Editor's Choice - 2017 ESC Guidelines on the Diagnosis and Treatment of Peripheral Arterial Diseases, in collaboration with the European Society for Vascular Surgery (ESVS)

Diagnosis and treatment of ischemia-producing coronary stenoses improves 5-year survival of patients undergoing major vascular surgery

OBJECTIVE

Patients undergoing vascular surgery procedures have poor long-term survival due to coexisting coronary artery disease (CAD), which is often asymptomatic, undiagnosed, and undertreated. We sought to determine whether preoperative diagnosis of asymptomatic (silent) coronary ischemia using coronary computed tomography (CT)-derived fractional flow reserve (FFRCT) together with postoperative ischemia-targeted coronary revascularization can reduce adverse cardiac events and improve long-term survival following major vascular surgery METHODS: In this observational cohort study of 522 patients with no known CAD undergoing elective carotid, peripheral, or aneurysm surgery we compared two groups of patients. Group I included 288 patients enrolled in a prospective Institutional Review Board-approved study of preoperative coronary CT angiography (CTA) and FFRCT testing to detect silent coronary ischemia with selective postoperative coronary revascularization in addition to best medical therapy (BMT) (FFRCT guided), and Group II included 234 matched controls with standard preoperative cardiac evaluation and postoperative BMT alone with no elective coronary revascularization (Usual Care). In the FFRCT group, lesion-specific coronary ischemia was defined as FFRCT ≤0.80 distal to a coronary stenosis, with severe ischemia defined as FFRCT ≤0.75. Results were available for patient management decisions. Endpoints included all-cause death, cardiovascular death, myocardial infarction (MI), and major adverse cardiovascular events (MACE [death, MI, or stroke]) during 5-year follow-up.

RESULTS

The two groups were similar in age, gender, and comorbidities. In FFRCT, 65% of patients had asymptomatic lesion-specific coronary ischemia, with severe ischemia in 52%, multivessel ischemia in 36% and left main ischemia in 8%. The status of coronary ischemia was unknown in Usual Care. Vascular surgery was performed as planned in both cohorts with no difference in 30-day mortality. In FFRCT, elective ischemia-targeted coronary revascularization was performed in 103 patients 1 to 3 months following surgery. Usual Care had no elective postoperative coronary revascularizations. At 5 years, compared with Usual Care, FFRCT guided had fewer all-cause deaths (16% vs 36%; hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.22-0.60; P < .001), fewer cardiovascular deaths (4% vs 21%; HR, 0.11; 95% CI, 0.04-0.33; P < .001), fewer MIs (4% vs 24%; HR, 0.13; 95% CI, 0.05-0.33; P < .001), and fewer MACE (20% vs 47%; HR, 0.36; 95% CI, 0.23-0.56; P < .001). Five-year survival was 84% in FFRCT compared with 64% in Usual Care (P < .001).

CONCLUSIONS

Diagnosis of silent coronary ischemia with ischemia-targeted coronary revascularization in addition to BMT following major vascular surgery was associated with fewer adverse cardiovascular events and improved 5-year survival compared with patients treated with BMT alone as per current guidelines.

Rationale and design for the randomized placebo-controlled double-blind trial studying the effect of single antiplatelet therapy (clopidogrel) versus dual antiplatelet therapy (clopidogrel/acetylsalicylic acid) on the occurrence of atherothrombotic events following lower extremity peripheral transluminal angioplasty (CLEAR-PATH)

RATIONALE

Antiplatelet therapy (APT) is the standard of care after endovascular revascularization (EVR) in patients with peripheral artery disease (PAD). APT aims to prevent both major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Nonetheless, the rates of MACE and MALE after EVR remain high. In coronary artery and cerebrovascular disease, dual APT (DAPT)compared to acetylsalicylic acid alone has been proven to reduce MACE without increasing the risk of major bleeding when applied for a restricted number of weeks. However, within the PAD population, insufficient data are available to understand the potential attributable effect of DAPT over single APT (SAPT). Therefore, prospective randomized studies in targeted study populations are warranted.

TRIAL DESIGN

CLEAR-PATH is a Dutch multicenter, double-blind, placebo-controlled, randomized trial comparing SAPT (clopidogrel 75 mg plus placebo) with DAPT (clopidogrel 75 mg plus acetylsalicylic acid 80 mg) in patients with PAD undergoing EVR. CLEAR-PATH includes a time-to-event analysis with a follow-up of one year. The primary composite efficacy endpoint consists of all-cause mortality, nonfatal stroke, nonfatal myocardial infarction, severe limb ischemia, (indication for) re-intervention due to any symptomatic restenosis, re-occlusion, or due to acute limb ischemia, and major amputation. The primary safety endpoint contains major bleeding following the Thrombolysis in Myocardial Infarction classification. The enrolment started in August 2022. In total 450 primary efficacy outcome events are required which expectedly amounts to 1696 subjects. Recruitment will take approximately 36 months.

CONCLUSION

CLEAR-PATH will assess the efficacy and safety of DAPT compared to SAPT following EVR in PAD patients.

TRIAL REGISTRATION NUMBER

NL80009.041.21.

Endovascular Treatment as an Alternative to Bypass Surgery for Juxtarenal Aortic Occlusion: Results from the CHAOS (CHronic Abdominal Aortic Occlusion, ASian Multicenter) Registry

BACKGROUND

Juxtarenal aortic occlusion (JRAO), in which the occlusion of the aorta extends to just below the renal artery, is often treated by bypass surgery because of concerns about the risk of procedural failure and fatal embolization to abdominal organs when treated with endovascular treatment (EVT). This study assessed the outcome of EVT for JRAO compared with aorto-biiliac /aorto-bifemoral (AOB) or axillo-bifemoral (AXB) bypass.

METHODS

A retrospective review of an international database created by 30 centers in Asia (CHronic Abdominal Aortic Occlusion, ASian Multicenter registry) was performed for patients who underwent revascularization for chronic total occlusion of the infrarenal aorta from 2007 to 2017. Of the 436 patients, 130 with JRAO (Forty-seven AOBs, 32 AXBs, and 51 EVTs) from 25 institutions were included in this study.

RESULTS

Patients were significantly older in the AXB and EVT groups and more malnourished in the EVT group than the AOB group. EVT was attempted but failed in 1 patient. Seven patients (1 [2.1%] in the AOB group, 1 [3.1%] in the AXB group, and 5 [9.8%] in the EVT group) died during hospitalization, but most of the causes in the EVT group were not related to the revascularization procedure. No visceral embolism was observed, which had been concerned, even though protection was performed only in 2 cases of the EVT group. At the latest follow-up (median duration 3.0 years), the ankle-brachial pressure index was significantly higher in the order of AOB, EVT, and AXB. At 4 years, the estimated primary and secondary patency rates of the AOB group (87.5% and 90.3%, respectively) were significantly higher than the AXB group (66.7% and 68.6%, respectively).

CONCLUSIONS

AOB remains the gold standard and should be the first choice for acceptable risk patients. For frail patients, EVT is a good option and likely preferable as a first-line treatment compared to AXB.

Single Tract Aortic Revascularization Technique in the Treatment of Aortoiliac Occlusive Disease

Endovascular treatment is an acceptable option for patients with aortoiliac occlusive disease. However, bilateral passage of guidewires through the aortoiliac occlusion can be a challenging step in achieving successful revascularization. The aim of this article is to present a novel strategy for successfully passing bilateral guidewires through long aortoiliac occlusive lesions. After one guidewire is passed through the aortic and iliac lesions via one side of the femoral artery, the other guidewire is passed using the up-and-over technique and pulled out from the ipsilateral side of the body. This contralateral guidewire is then inserted into the ipsilateral angiographic catheter along with the ipsilateral guidewire. Subsequently, the angiographic catheter is removed in a manner similar to a peel-away sheath. Eventually, bilateral guidewires can be passed through the lesion via a single aortic tract.

Perioperative platelet reactivity over time in patients undergoing vascular surgery: An observational pilot study

BACKGROUND

Despite Antiplatelet therapy (APT), cardiovascular patients undergoing revascularisation remain at high risk for thrombotic events. Individual response to APT varies substantially, resulting in insufficient protection from thrombotic events due to high on-treatment platelet reactivity (HTPR) in ≤40% of patients. Individual variation in platelet response impairs APT guidance on a single patient level. Unfortunately, little is known about individual platelet response to APT over time, timing for accurate residual platelet reactivity measurement, or the optimal test to monitor residual platelet reactivity.

AIMS

To investigate residual platelet reactivity variability over time in individual patients undergoing carotid endarterectomy (CEA) treated with clopidogrel.

METHODS

Platelet reactivity was determined in patients undergoing CEA in a prospective, single-centre, observational study using the VerifyNow (change in turbidity from ADP-induced binding to fibrinogen-coated beads), the VASP assay (quantification of phosphorylation of vasodilator-stimulated phosphoprotein), and a flow-cytometry-based assay (PACT) at four perioperative time points. Genotyping identified slow (CYP2C19*2 and CYP2C19*3) and fast (CYP2C19*17) metabolisers.

RESULTS

Between December 2017 and November 2019, 50 patients undergoing CEA were included. Platelet reactivity measured with the VerifyNow (p = < .001) and VASP (p = .029) changed over time, while the PACT did not. The VerifyNow identified patients changing HTRP status after surgery. The VASP identified patients changing HTPR status after eight weeks (p = .018). CYP2C19 genotyping identified 13 slow metabolisers.

CONCLUSION

In patients undergoing CEA, perioperative platelet reactivity measurements fluctuate over time with little agreement between platelet reactivity assays. Consequently, HTPR status of individual patients measured with the VerifyNow and VASP assay changed over time. Therefore, generally used perioperative platelet reactivity measurements seem unreliable for adjusting perioperative APT strategy.

One-year limb salvage and quality of life following mechanical aspiration thrombectomy in patients with acute lower extremity ischemia

OBJECTIVE

Lower extremity acute limb ischemia (LE-ALI) is associated with high morbidity and mortality rates, and a burden on patient quality of life (QoL). There is limited medium- to long-term evidence on mechanical aspiration thrombectomy (MT) in patients with LE-ALI. The STRIDE study was designed to assess safety and efficacy of MT using the Indigo Aspiration System in patients with LE-ALI. Thirty-day primary and secondary endpoints and additional outcomes were previously published. Here, we report 365-day secondary endpoints and QoL data from STRIDE.

METHODS

STRIDE was a multicenter, prospective, single-arm, observational cohort study that enrolled 119 patients across 16 sites in the United States and Europe. Patients were treated first-line with MT using the Indigo Aspiration System (Penumbra, Inc). The study completed follow-up in October 2023. Secondary endpoints at 365 days included target limb salvage and mortality. Additionally, the VascuQoL-6 questionnaire, developed for evaluating patient-centered QoL outcomes for peripheral arterial disease, was assessed at baseline and follow-up through 365 days.

RESULTS

Seventy-three percent of patients (87/119) were available for 365-day follow-up. Mean age of these patients was 65.0 ± 13.3 years, and 44.8% were female. Baseline ischemic severity was classified as Rutherford I in 12.6%, Rutherford IIa in 51.7%, and Rutherford IIb in 35.6%. In general, baseline and disease characteristics (demographics, medical history, comorbidities, target thrombus) of these patients are similar to the enrolled cohort of 119 patients. The secondary endpoints at 365 days for target limb salvage was 88.5% (77/87) and mortality rate was 12.0% (12/100). VascuQoL-6 improved across all domains, with a median total score improvement from 12.0 (interquartile range, 9.0-15.0) at baseline to 19.0 (interquartile range, 16.0-22.0) at 365 days.

CONCLUSIONS

These 365-day results from STRIDE demonstrate that first-line MT with the Indigo Aspiration System for LE-ALI portray continued high target limb salvage rates and improved patient-reported QoL. These findings indicate Indigo as a safe and effective therapeutic option for LE-ALI.

Covered Endovascular Reconstruction of the Iliac Artery Bifurcation (CERIB)

PURPOSE

The aim of this study was to present the covered endovascular reconstruction of the iliac artery bifurcation (CERIB) technique as a revascularization option for aorto-iliac occlusive disease (AIOD) involving the iliac artery bifurcation.

METHODS

This was a retrospective single-center study including all patients undergoing a CERIB procedure from January 2021 until December 2022. Covered endovascular reconstruction of the iliac artery bifurcation procedures were performed percutaneously with bilateral femoral access, excepting cases where simultaneous open femoral artery reconstruction was required due to the extension of peripheral arterial occlusive disease. Standard patient, procedural, and follow-up (FU) data including survival and arterial reinterventions were gathered and analyzed.

RESULTS

A total of 13 patients were included (11/13 male, median age=70 [60-76] years). Additional open and/or endovascular procedures included endarterectomy of the femoral bifurcation (n=6), rotational atherectomy (n=2), and 1 axillary artery cutdown for upper limb access (n=1). Median operating time was 2.9 hours (1.5-4.9 hours); median radiation duration and dose were 28.4 (14.3-63.3 minutes) and 4090.6 (384.4-9430.1 cGray/cm2), respectively. The stent grafts used for CERIB were BeGraft peripheral n=31, BeGraft Aortic n=4 and BeGraft peripheral plus n=1 (Bentley InnoMed GmbH, Hechingen, Germany). In 2 patients with prior stenting of the common iliac artery (CIA), only the internal and external iliac arteries (IIA and EIA) were treated in this study, and in 2 cases, additional uncovered stents were required for relining. Technical success was 100%. During a midterm FU (median 18 [4-31] months), 2 patients died from cardiovascular reasons and 1 patient with prior iliac stenting required reinterventions for recurring occlusion.

CONCLUSION

Covered endovascular reconstruction of the iliac artery bifurcation is a straightforward option for treating AIOD involving the iliac artery bifurcation that allows preservation of internal iliac artery perfusion and shows good early and midterm results. Prior iliac artery stenting may be a risk factor for early occlusion after CERIB.

CLINICAL IMPACT

Aorto-iliac occlusive disease with involvement of the internal iliac artery is encountered regularly in vascular surgical practice, but the internal iliac artery is often not included in the revascularization strategy. The present article will increase the awareness for the relevance of including the internal iliac artery in revascularization strategies and presents CERIB as another method to be added to the armamentarium of (endo-)vascular surgeons and interventionalists.

The use of fetal bovine acellular dermal matrix in severe diabetic foot ulceration and threatened limbs with tissue loss the use of FBADM as an adjunct for complex wounds

OBJECTIVES

Foot ulceration associated with diabetic foot disease (DFD) and chronic limb-threatening ischaemia (CLTI) presents a complex clinical challenge and failure to heal the wound imposes a significant risk of major limb amputation (MLA). In attempt to accelerate wound healing rates and decrease MLA, tissue engineering research into bio-engineered scaffolds and skin substitutes has become a growing area of interest. Advanced wound therapies such as fetal bovine acellular dermal matrix (FBADM) may have success in the treatment of difficult to heal chronic foot ulcers. The FBADM traps and binds the patients' own epithelial cells to rebuild the dermis layer of the skin. Previous studies have suggested that wounds treated with FBADM had a faster healing rate than wounds managed with conventional dressings. However, these studies excluded foot wounds with chronic exposed bone or tendon, active infection, gangrene, or osteomyelitis and patients with uncontrolled blood glucose levels were excluded. The aim of this study was to assess the efficacy of FBADM for patients admitted to hospital acutely with severe foot ulceration secondary to DFD and CLTI.

METHODS

Between February 2020 and December 2021, inpatients admitted acutely at a single tertiary centre with a severe non-healing foot ulcer and had a wound suitable for application of a FBADM after primary debridement were included in the study. A severe non-healing foot wound was defined as a Society for Vascular Surgery Wound, Ischaemia, and foot Infection (WIfI) stage of 3 or 4. Participants were prospectively followed up at regular intervals at a multidisciplinary high-risk diabetic foot clinic until June 2022. The primary endpoint was time to wound closure. The secondary endpoints were number of applications of FBADM, readmission rate and amputation-free survival.

RESULTS

There were 22 patients included in the study with a median age of 71 (50-87) years and 15 were male. Five patients had a WIfI stage of 3 and 17 had a WIfI score of 4. Overall, 14 patients required revascularisation procedures (6 open surgery,8 endovascular intervention). A total of 18 patients achieved complete wound healing with a median time to wound healing of 178 (28-397) days. Two patients underwent a MLA and two patients died prior to complete wound healing. The median length of stay was 16.5 (5-115) days, and 4 patients were readmitted to hospital within 12 months.

CONCLUSION

FBADM may be a useful adjunct in the acute setting of complex DFD and CLTI ulceration to assist with wound healing. Future comparative prospective studies are required to further validate these preliminary findings.

Growth Differentiation Factor-15 and Clinical Outcomes in Lower Extremity Artery Disease

AIM

Lower extremity artery disease (LEAD) is an increasingly common health problem that is associated with high mortality due to thrombotic and bleeding events. Growth differentiation factor-15 (GDF15), a stress-response cytokine belonging to the transforming growth factor-beta superfamily, is associated with cardiovascular disease and its outcomes. The aim of the present study was to examine the effect of serum GDF15 levels on clinical outcomes in patients with LEAD.

METHODS

We measured serum GDF15 levels in 200 patients with LEAD before their initial endovascular therapy. The primary endpoint was the all-cause mortality rate. The secondary endpoints, on the other hand, were thrombotic and bleeding events, such as cerebral infarction, acute coronary syndrome, acute limb ischemia, and Bleeding Academic Research Consortium types 3 and 5.

RESULTS

The serum GDF15 levels increased with advancing Fontaine class. Kaplan-Meier analysis revealed that the high-GDF15 group (≥ 2,275 pg/mL) had higher rates of all-cause deaths and thrombotic and bleeding events than the low-GDF15 group (＜2,275 pg/mL). Multivariate Cox proportional-hazards regression analysis revealed that GDF15 was an independent predictor of all-cause mortality and thrombotic and bleeding events after adjusting for confounding risk factors. When the ABC-AF-bleeding score was substituted for GDF15, similar results were obtained.

CONCLUSION

Serum GDF15 levels were associated with all-cause mortality and thrombotic and bleeding events in patients with LEAD. Serum GDF15 is a potentially useful marker of clinical outcomes, specifically for tracking thrombotic and bleeding events in patients with LEAD.

Antithrombotic and Lipid Lowering Therapy is Associated With Improved Survival After Vascular Surgery: A Population Based Study From Norway

OBJECTIVE

This population based retrospective cohort study aimed to investigate the association between combined treatment with lipid lowering drugs and antiplatelet or anticoagulation therapy and long term survival following vascular surgery in Norway.

METHODS

The study included all patients who were registered for the treatment of carotid stenosis, abdominal aortic aneurysm (AAA), and atherosclerotic lower extremity arterial disease (LEAD) in the Norwegian Registry for Vascular Surgery between 2015 and 2019 and who were discharged alive. Clinical and medication details were retrieved from the register. Survival was assessed with Kaplan-Meier analysis and a multivariable Cox regression model. Stratification was according to treatment group, patient sex, and if patients received the recommended medications or not. Recommended medications were defined as lipid lowering drugs, usually statins, and antiplatelets, or sometimes anticoagulants, when comorbidity indicated anticoagulation therapy.

RESULTS

In total, 15 810 patients had LEAD, 4 080 patients AAA, and 2 194 patients had carotid stenosis. In all treatment groups, survival was superior for patients who used the recommended medications upon discharge. The difference was greatest in patients with LEAD with mean survival periods of 4.33 (95% CI 4.29 - 4.36) and 3.7 (95% CI 3.64 - 3.77) years in patients discharged with and without the recommended medications, respectively (p < .001). The mean survival periods were 4.67 (95% CI 4.61 - 4.73) and 4.34 (95% CI 4.24 - 4.44) years in patients with AAA discharged with and without the recommended medications, respectively (p < .001). Cox regression analysis showed a statistically significantly lower mortality rate for patients discharged with the recommended medications for LEAD (HR 0.58; p < .001) and AAA (HR 0.57; p < .001).

CONCLUSION

The recommended medications were associated with improved survival in all treatment groups and both sexes. The survival difference was statistically significant in patients with LEAD and AAA. Patients with LEAD had the greatest improvement; therefore, the recommended secondary prophylaxis is especially important in these patients.

Adherence and Persistence to Antiplatelet Therapy in Lower Extremity Peripheral Arterial Disease: A Danish Population Based Cohort Study

OBJECTIVE

Adherence to antiplatelet therapy is recommended but unexplored in patients with symptomatic lower extremity peripheral arterial disease (PAD). Therefore, this study aimed to determine adherence and persistence to antiplatelet therapy in patients with PAD, defined as intermittent claudication and chronic limb threatening ischaemia.

DESIGN

Population based nationwide cohort study.

METHODS

This study included all Danish citizens aged ≥ 40 years with a first inpatient or outpatient diagnosis of symptomatic PAD between 2010 - 2017, and who had at least one prescription claim for aspirin and/or clopidogrel within 90 days after diagnosis. Adherence was determined by the proportion of days covered (PDC) during the first year after diagnosis. Persistence was defined as no treatment gap ≥ 30 days between prescription renewals over three year follow up.

RESULTS

A total of 39 687 patients were eligible for inclusion, of whom 23 279 (58.7%) claimed a prescription for aspirin and/or clopidogrel within 90 days of diagnosis. Among these, 12 898 (55.4%) were prevalent users, while the remainder comprised new users who initiated the therapy after the index PAD diagnosis. The mean PDC was 74.5% (SD 35.0%) for prevalent users and 60.5% (SD 30.5%) for new users. Adherence increased with age and number of concomitant drugs. The overall one year cumulative incidence treatment discontinuation was 13.0% (95% CI 12.5 - 13.4%) overall, 17.2% (CI 16.6 - 17.9%) for prevalent users, and 7.9% (CI 7.4 - 8.4%) for new users. At three year follow up, the cumulative incidence of discontinuation was 31.5% (CI 30.9 - 32.2%) overall, 44.6% (CI 43.7 - 45.4%) for prevalent users, and 14.6% (CI 13.9 - 15.3) for new users.

CONCLUSION

Less than 60% of patients with newly diagnosed symptomatic PAD claimed a prescription for antiplatelet therapy within 90 days of diagnosis, and both adherence and persistence were moderate during the first year after diagnosis. These findings underscore the importance of efforts to improve the initiation and continuation of antiplatelet therapy in patients with PAD.

Extracorporeal Shockwave for Intermittent Claudication and Quality of Life: A Randomized Clinical Trial

Importance

Intermittent lower limb claudication limits function and quality of life. Supervised exercise programs are not readily available, and a noninvasive alternative is needed.

Objective

To assess extracorporeal corporeal shockwave therapy in improving quality of life in patients with claudication.

Design, Setting, and Participants

In this double-blind, placebo-controlled randomized clinical trial, patients in the outpatient setting at a single tertiary center for vascular surgery were randomized in a 1:1 ratio to extracorporeal shockwave therapy or placebo therapy with no shockwaves delivered. Recruitment was between June 2015 and January 2020, with 12-week follow-up ending in March 2020. A convenience sample of patients with claudication and conservative treatment requirements who refused or were unable to participate in supervised exercise were eligible. Patients receiving anticoagulation therapy or with an active cancer were excluded. Of 522 patients screened, 389 were eligible, 138 were enrolled, and 110 completed follow-up and were included in the primary analysis. Statistical analysis was completed by May 2021.

Intervention

In the intervention group, patients received 100 impulses of 0.1mJ/mm/cm2 in an area of the gastrocnemius muscle 3 times weekly for 3 weeks. The steps for treatment were replicated for the control group without delivering the treatment.

Main Outcomes and Measures

The primary outcome was the Physical Functioning domain of the 36-item Short-Form Quality of Life Questionnaire at 12-week follow-up. Secondary outcomes included walking distances, ankle brachial pressure index, and other quality-of-life measures.

Results

Of 138 patients recruited and randomized, 92 (67%) were male, and the mean (SD) age of the study population was 67 (9.6) years. The intervention group had a significantly higher physical function score at 12 weeks (estimated median difference 3.8; 95% CI, 0.0-7.7; P = .03). However, this significance did not remain when adjusting for covariates. At 12 weeks, the intervention group had significantly longer pain-free and maximum walking distances (pain-free estimated median difference, 34.1, 95% CI, 11.4-56.8; P = .004; maximum estimated median difference, 51.4; 95% CI, 10.7-86.5; P = .01).

Conclusions and Relevance

To our knowledge, this is the first double-blind, placebo-controlled, randomized clinical trial to consider extracorporeal shockwave therapy for the management of intermittent claudication. It demonstrated efficacy for walking distances, may have a positive effect on quality of life, and may provide a safe, noninvasive alternative therapy for patients with intermittent claudication.

Trial Registration

ClinicalTrials.gov Identifier: NCT02652078.

Surveillance After Surgical and Endovascular Treatment for Peripheral Artery Disease: a Dutch Survey

OBJECTIVE

At present, there is no clear, optimal approach to surveillance after invasive treatment of peripheral artery disease (PAD) in terms of modality, duration, clinical benefit, and cost effectiveness. The ongoing debate on the clinical benefit and cost effectiveness of standard surveillance creates a clear knowledge gap and may result in overtreatment or undertreatment. In this study, a survey was conducted among vascular surgeons in the Netherlands to assess the currently applied surveillance programmes.

METHODS

All vascular surgeons from the Dutch Society for Vascular Surgery received an online survey on follow up after open and endovascular revascularisation in patients with PAD. Surveillance was defined as at least one follow up visit after intervention with or without additional imaging or ankle brachial index (ABI) measurement. Ten types of PAD intervention were surveyed.

RESULTS

Surveys were returned by 97 (46.2%) of 210 vascular surgeons, and 76% reported using a routine follow up protocol after an invasive intervention. Clinical follow up only is most commonly performed after femoral endarterectomy (53%). After peripheral bypass surgery, clinical follow up only is applied rarely (4 - 8%). In six of the 10 interventions surveyed, duplex ultrasound (DUS) was the most used imaging modality for follow up. After bypass surgery, 76 - 86% of vascular surgeons perform DUS with or without ABI measurement. After endovascular interventions, 21 - 60% performed DUS surveillance. Lifelong surveillance is most often applied after aortobifemoral bypass (57%). Surveillance frequency and duration vary greatly within the same intervention. Frequencies range from every three or six months to annually. Duration ranges from one time surveillance to lifelong follow up.

CONCLUSION

There is significant practice variation in surveillance after surgical and endovascular treatment of patients with PAD in the Netherlands. Prospective studies to evaluate treatment outcomes and to define the clinical need and cost effectiveness of standardised surveillance programmes for patients with PAD are recommended.

Gupta Perioperative Risk for Myocardial Infarction or Cardiac Arrest score is a long-term cardiovascular risk predictor after aortoiliac revascularization

INTRODUCTION

Gupta Perioperative Risk for Myocardial Infarction or Cardiac Arrest (MICA) is a validated self-explanatory score applied in cardiac or non-cardiac surgeries. This study aims to assess the predictive value of the MICA score for cardiovascular events after aortoiliac revascularization.

METHODS

This prospective cohort underwent elective aortoiliac revascularization between 2013 and 2021. Patients' demographic, clinical characteristics and outcomes were registered. The patients were divided into two groups according to the MICA score using optimal binning. Survival analysis to test for time-dependent variables and multivariate Cox regression analysis for independent predictors were performed.

RESULTS

This study included 130 patients with a median follow-up of 55 months. Preoperative MICA score was ≥ 6.5 in 41 patients. MICA ≥ 6.5 presented a statistically significant association with long-term occurrence of acute heart failure (HR=1.695, 95% CI 1.208-2.379, p=0.002), major adverse cardiovascular events (HR=1.222, 95% CI 1.086-1.376, p<0.001) and all-cause mortality (HR=1.256, 95% CI 1.107-1.425, p<0.001). Multivariable Cox regression confirmed MICA as a significant independent predictor of long-term major adverse cardiovascular events (aHR=1.145 95%CI 1.010-1.298, p=0.034) and all-cause mortality (aHR=1.172 95%CI 1.026-1.339, p=0.020).

CONCLUSION

The MICA score is a quick, easy-to-obtain, predictive tool in identifying patients with a higher risk of post-aortoiliac revascularization cardiovascular events, such as acute heart failure, major adverse cardiovascular events and all-cause mortality. Additional research for validation of the MICA score in the context of aortoiliac revascularization and specific interventions are necessary.

Percutaneous Endovascular Reconstruction of the Common Femoral Artery and Its Bifurcation

Occlusive lesions of the common femoral artery (CFA) and its bifurcation have traditionally been treated with open surgery. Although long-term patency rates after open surgery are excellent, such repairs are associated with substantial local and general morbidity. In recent years, different treatment options have emerged within percutaneous endovascular repair. We hereby present a narrative review on endovascular treatment modalities and a treatment algorithm for endovascular revascularisation of the CFA and its bifurcation. Lesion analysis, access issues, vessel preparation tools, and types of repairs with or without the involvement of the bifurcation are described. Based on current data, an interventional approach can result in high technical success and acceptable mid-term patency rates. Further comparative evidence with open surgery and/or between the different types of endovascular repairs is required to improve the current treatment algorithm.

The phenomenon of drug-coating embolism during lower extremity endovascular interventions with paclitaxel-coated balloon

INTRODUCTION

There is a risk of distal embolization lower extremity endovascular interventions. Possibly a drug-coating embolism caused by coating detachment from intravascular devices.

METHODS

This review focuses on providing updated information on distal embolism in endovascular revascularization of lower extremity arteries, including the use of drug-coated balloons.

RESULTS

Drug-coating embolism is a special case of distal embolization during recanalization of the arteries of the lower extremities. Preclinical studies have demonstrated embolization of drug-coated balloons during angioplasty of lower extremity arteries. However, the clinical role of drug-coating embolism is not completely clear. A 2020 meta-analysis found an increased risk of major lower extremity amputation after drug-coated balloon angioplasty in patients with critical limb ischemia. But long-term research is emerging to support the safety of using these devices. Perhaps a more thorough assessment of the quality of life and the degree of compensation of lower limb ischemia with an intraoperative assessment of the frequency of peripheral embolizations using ultrasound emboli detection, as well as microcirculation with transcutaneous oximetry and laser Doppler flowmetry of the operated lower limb will allow a more detailed study of the phenomenon of drug-coating embolism and its impact on long-term clinical outcomes.

CONCLUSION

According to the results of preclinical studies, the use of paclitaxel-coated balloons leads to an increase in the concentration of paclitaxel in distal skeletal muscles. However, paclitaxel concentration in skeletal muscle was significantly higher in first-generation DCBs. The non-target effects of drug-coating balloon are not fully understood and require further study. Understanding the phenomenon of drug-coating embolism can help physicians to better assess the patient risk and to minimize complications.

Documentary analysis of national and international guidance for community clinicians referring patients with suspected chronic limb-threatening ischaemia

BACKGROUND

Delayed referral of patients with chronic limb-threatening ischaemia (CLTI) from the community to vascular services may increase risk of amputation due to delayed revascularisation. Lack of appropriate guidance for clinicians in the community may contribute to this problem. This documentary analysis investigated referral guidance available to primary care clinicians.

METHODS

National and international documents providing guidance on CLTI management were identified by searching sources including Medline, Embase, Guidelines International Network and College/Society websites. Data were extracted on referral recommendations, target audience and author groups. Recommendations were coded according to the Behaviour Change Technique Taxonomy. Clinical practice guideline quality and ease of implementation were assessed independently by two reviewers using the Appraisal of Guidelines Research and Evaluation (AGREE) II and Guideline Implementability Appraisal (GLIA) tools, respectively.

RESULTS

12 documents containing guidance on CLTI referrals were included. Five were clinical practice guidelines. Nine targeted clinicians in the community among their audience, yet only one included a primary care clinician in their author group. Recommendations on identification and referral of CLTI were often in non-specific language and frequently assumed specialist knowledge of vascular disease. Just 4 of the 93 behaviour change techniques were identified in the guidance documents. Three relevant domains of the AGREE II tool were scored for five clinical practice guidelines: stakeholder involvement (range 21.4%-52.4%, mean 42.9%), clarity of presentation (range 71.4%-92.9%, mean 82.9%) and applicability (25.0%-57.1%, mean 36.8%). The GLIA tool identified barriers to ease of implementation for all five clinical practice guidelines.

CONCLUSIONS

Most guidance for clinicians in the community on the management of CLTI has been written without their input and assumes knowledge of vascular disease, which may be lacking. Future guidance development should involve community clinicians, consider using additional behaviour change techniques, and improve the applicability and ease of implementation of recommendations.

Dual Antithrombotic Therapy versus Anticoagulant Monotherapy for Major Adverse Limb Events in Patients with Concomitant Lower Extremity Arterial Disease and Atrial Fibrillation: A Propensity Score Weighted Analysis

OBJECTIVE

Patients with symptomatic lower extremity arterial disease (LEAD) are recommended to receive antiplatelet therapy, while direct oral anticoagulants (DOACs) are standard for stroke prevention in patients with atrial fibrillation (AF). For patients with concomitant LEAD and AF, data comparing dual antithrombotic therapy (an antiplatelet agent used in conjunction with a DOAC) vs. DOAC monotherapy are scarce. This retrospective cohort study, based on data from the Taiwan National Health Insurance Research Database, aimed to compare the efficacy and safety of these antithrombotic strategies.

METHODS

Patients with AF who underwent revascularisation for LEAD between 2012 - 2020 and received any DOAC within 30 days of discharge were included. Patients were grouped by antiplatelet agent exposure into the dual antithrombotic therapy and DOAC monotherapy groups. Inverse probability of treatment weighting was used to mitigate selection bias. Major adverse limb events (MALEs), ischaemic stroke or systemic embolism, and bleeding outcomes were compared. Patients were followed until the occurrence of any study outcome, death, or up to two years.

RESULTS

A total of 1 470 patients were identified, with 736 in the dual antithrombotic therapy group and 734 in the DOAC monotherapy group. Among them, 1 346 patients received endovascular therapy as the index revascularisation procedure and 124 underwent bypass surgery. At two years, dual antithrombotic therapy was associated with a higher risk of MALEs than DOAC monotherapy (subdistribution hazard ratio [SHR] 1.34, 95% confidence interval [CI] 1.15 - 1.56), primarily driven by increased repeat revascularisation. Dual antithrombotic therapy was also associated with a higher risk of major bleeding (SHR 1.43, 95% CI 1.05 - 1.94) and gastrointestinal bleeding (SHR 2.17, 95% CI 1.42 - 3.33) than DOAC monotherapy.

CONCLUSION

In patients with concomitant LEAD and AF who underwent peripheral revascularisation, DOAC monotherapy was associated with a lower risk of MALEs and bleeding events than dual antithrombotic therapy.

Predicting Outcomes Following Lower Extremity Endovascular Revascularization Using Machine Learning

BACKGROUND

Lower extremity endovascular revascularization for peripheral artery disease carries nonnegligible perioperative risks; however, outcome prediction tools remain limited. Using machine learning, we developed automated algorithms that predict 30-day outcomes following lower extremity endovascular revascularization.

METHODS AND RESULTS

The National Surgical Quality Improvement Program targeted vascular database was used to identify patients who underwent lower extremity endovascular revascularization (angioplasty, stent, or atherectomy) for peripheral artery disease between 2011 and 2021. Input features included 38 preoperative demographic/clinical variables. The primary outcome was 30-day postprocedural major adverse limb event (composite of major reintervention, untreated loss of patency, or major amputation) or death. Data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, 6 machine learning models were trained using preoperative features. The primary model evaluation metric was area under the receiver operating characteristic curve. Overall, 21 886 patients were included, and 30-day major adverse limb event/death occurred in 1964 (9.0%) individuals. The best performing model for predicting 30-day major adverse limb event/death was extreme gradient boosting, achieving an area under the receiver operating characteristic curve of 0.93 (95% CI, 0.92-0.94). In comparison, logistic regression had an area under the receiver operating characteristic curve of 0.72 (95% CI, 0.70-0.74). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.09. The top 3 predictive features in our algorithm were (1) chronic limb-threatening ischemia, (2) tibial intervention, and (3) congestive heart failure.

CONCLUSIONS

Our machine learning models accurately predict 30-day outcomes following lower extremity endovascular revascularization using preoperative data with good discrimination and calibration. Prospective validation is warranted to assess for generalizability and external validity.

Endovascular therapy versus bypass for chronic limb-threatening ischemia in a real-world practice

OBJECTIVE

The recent Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) study showed that bypass was superior to endovascular therapy (ET) in patients with chronic limb-threatening ischemia (CLTI) deemed suitable for either approach who had an available single-segment great saphenous vein (GSV). However, the superiority of bypass among those lacking GSV was not established. We aimed to examine comparative treatment outcomes from a real-world CLTI population using the Vascular Quality Initiative-Medicare-linked database.

METHODS

We queried the Vascular Quality Initiative-Medicare-linked database for patients with CLTI who underwent first-time lower extremity revascularization (2010-2019). We performed two one-to-one propensity score matchings (PSMs): ET vs bypass with GSV (BWGSV) and ET vs bypass with a prosthetic graft (BWPG). The primary outcome was amputation-free survival. Secondary outcomes were freedom from amputation and overall survival (OS).

RESULTS

Three cohorts were queried: BWGSV (N = 5279, 14.7%), BWPG (N = 2778, 7.7%), and ET (N = 27,977, 77.6%). PSM produced two sets of well-matched cohorts: 4705 pairs of ET vs BWGSV and 2583 pairs of ET vs BWPG. In the matched cohorts of ET vs BWGSV, ET was associated with greater hazards of death (hazard ratio [HR] = 1.34, 95% confidence interval [CI], 1.25-1.43; P < .001), amputation (HR = 1.30, 95% CI, 1.17-1.44; P < .001), and amputation/death (HR = 1.32, 95% CI, 1.24-1.40; P < .001) up to 4 years. In the matched cohorts of ET vs BWPG, ET was associated with greater hazards of death up to 2 years (HR = 1.11, 95% CI, 1.00-1.22; P = .042) but not amputation or amputation/death.

CONCLUSIONS

In this real-world multi-institutional Medicare-linked PSM analysis, we found that BWGSV is superior to ET in terms of OS, freedom from amputation, and amputation-free survival up to 4 years. Moreover, BWPG was superior to ET in terms of OS up to 2 years. Our study confirms the superiority of BWGSV to ET as observed in the BEST-CLI trial.

Outcomes of peripheral artery disease and polyvascular disease in patients with end-stage kidney disease

OBJECTIVE

Patients with peripheral artery disease (PAD) and end-stage kidney disease are a high-risk population, and concomitant atherosclerosis in coronary arteries (CAD) or cerebral arteries (CVD) is common. The aim of the study was to assess long-term outcomes of PAD and the impact of coexistent CAD and CVD on outcomes.

METHODS

The United States Renal Data System was used to identify patients with PAD within 6 months of incident dialysis. Four groups were formed: PAD alone, PAD with CAD, PAD with CVD, and PAD with CAD and CVD. PAD-specific outcomes (chronic limb-threatening ischemia, major amputation, percutaneous/surgical revascularization, and their composite, defined as major adverse limb events [MALE]) as well as all-cause mortality, myocardial infarction, and stroke were studied.

RESULTS

The study included 106,567 patients (mean age, 71.2 years; 40.8% female) with a median follow-up of 546 days (interquartile range, 214-1096 days). Most patients had PAD and CAD (49.8%), 25.8% had PAD alone, and 19.2% had all three territories involved. MALE rate in patients with PAD was 22.3% and 35.0% at 1 and 3 years, respectively. In comparison to PAD alone, the coexistence of both CAD and CVD (ie, polyvascular disease) was associated with a higher adjusted rates of all-cause mortality (hazard ratio [HR], 1.28; 95% confidence interval [CI], 1.24-1.31), myocardial infarction (HR, 1.78; 95% CI, 1.69-1.88), stroke (HR, 1.66; 95% CI, 1.52,1.80), and MALE (HR, 1.07; 95% CI, 1.04-1.11).

CONCLUSIONS

Patients with end-stage kidney disease have a high burden of PAD with poor long-term outcomes, which worsen, in an incremental fashion, with the involvement of each additional diseased arterial bed.

Adipose Derived Stromal Vascular Fraction and Mesenchymal Stem Cells Improve Angiogenesis in a Rat Hindlimb Ischaemia Model

OBJECTIVE

This study aimed to investigate the effect of human adipose tissue derived stromal vascular fraction (AD-SVF) and mesenchymal stem cells (AD-MSCs) on blood flow recovery and neovascularisation in a rat hindlimb ischaemia model.

METHODS

SVF was isolated using an automated centrifugal system, and AD-MSCs were obtained from adherent cultures of SVF cells. Rats were divided into four groups of six rats each: non-ischaemia (Group 1); saline treated ischaemia (Group 2); SVF treated ischaemia (Group 3); and AD-MSC treated ischaemia (Group 4). Unilateral hindlimb ischaemia was induced in Sprague-Dawley rats via femoral artery ligation. Saline, SVF, or AD-MSCs were injected intramuscularly into the adductor muscle intra-operatively. Cell viability was calculated as the percentage of live cells relative to total cell number. Blood flow improvement, muscle fibre injury, and angiogenic properties were validated using thermal imaging and histological assessment.

RESULTS

The viabilities of SVF and AD-MSCs were 83.3% and 96.7%, respectively. Group 1 exhibited no significant temperature difference between hindlimbs, indicating a lack of blood flow changes. The temperature gradient gradually decreased in SVF and AD-MSC treated rats compared with saline treated rats. In addition, only normal muscle fibres with peripherally located nuclei were observed in Group 1. Groups 3 and 4 exhibited significantly fewer centrally located nuclei, indicating less muscle damage compared with Group 2. Regarding angiogenic properties, CD31 staining of endothelial cells showed similar patterns among all groups, whereas expression of vascular endothelial growth factor, as a crucial angiogenesis factor, was enhanced in the SVF and AD-MSC treated groups.

CONCLUSION

SVF and AD-MSCs improved blood flow and neovascularisation in a rat hindlimb ischaemia model, suggesting their potential ability to promote angiogenesis. Further extensive research is warranted to explore their potential applications in the treatment of severe lower extremity arterial disease.

Impact of Calcification on the Outcomes of Femoropopliteal Artery Endovascular Treatment Using a Polymer Coated Drug-Eluting Stent

PURPOSE

The aim of this study was to analyze the impact of calcification on the 12 and 24 months outcomes of the Eluvia™ (Boston Scientific®) drug-eluting stent (DES) for femoropopliteal occlusive disease using three different calcium scoring systems.

MATERIAL AND METHODS

A single-center, retrospective cohort-study (March-2016 to December-2018) of patients treated with the Eluvia™ DES for femoropopliteal atherosclerosis was performed. Outcomes included primary and secondary patency rates and freedom from target lesion revascularization (FTLR) and were analyzed by comparing the impact of calcium burden according to the following calcium scores: Peripheral Arterial Calcium Scoring System (PACSS) score, number of vessel quadrants affected (0-4) and calcification score per Peripheral Academic Research Consortium (PARC) definitions.

RESULTS

In total, 111 Patients were included (mean age: 71.2 ± 7.9; 64% male). Most patients presented with Rutherford class 3 (79.9%), followed by class 5 (12.7%), class 4 (10%) and class 6 (6.4%). The mean lesion length was 197.6 ± 108.5 mm and 74.3% of patients had chronic total occlusions. There were no differences in primary patency between the calcification scores at 12 months (PACSS, LogRank = 0.28; quadrants, LogRank = 0.29; PARC, LogRank = 0.42) and 24 months (PACSS, LogRank = 0.13; quadrants, LogRank = 0.42; PARC, LogRank = 0.13). FTLR was significantly lower at 12 months in patients with calcification affecting 3 or 4 quadrants (LogRank = 0.022) but not at 24 months (LogRank = 0.36).

CONCLUSIONS

In this study, the Eluvia™ DES showed promising performance in calcified disease and the analysis according to the quadrant model predicted an increased risk for TLR at 12 months.

Ischemia-Guided Coronary Revascularization Following Lower-Extremity Revascularization Improves 5-Year Survival of Patients With Chronic Limb-Threatening Ischemia

PURPOSE

To determine whether diagnosis of asymptomatic (silent) coronary ischemia using coronary computed tomography (CT)-derived fractional flow reserve (FFRCT) together with targeted coronary revascularization of ischemia-producing coronary lesions following lower-extremity revascularization can reduce adverse cardiac events and improve long-term survival of patients with chronic limb-threatening ischemia (CLTI).

MATERIALS AND METHODS

Prospective cohort study of CLTI patients with no cardiac history or symptoms undergoing elective lower-extremity revascularization. Patients with pre-operative coronary computed tomography angiography (CTA) and FFRCT evaluation with selective post-operative coronary revascularization (FFRCT group) were compared with patients with standard pre-operative evaluation and no post-operative coronary revascularization (control group). Lesion-specific coronary ischemia was defined as FFRCT≤0.80 distal to a coronary stenosis with FFRCT≤0.75 indicating severe ischemia. Endpoints included all-cause death, cardiac death, myocardial infarction (MI) and major adverse cardiovascular (CV) events (MACE=CV death, MI, stroke, or unplanned coronary revascularization) during 5 year follow-up.

RESULTS

In the FFRCT group (n=111), FFRCT analysis revealed asymptomatic (silent) coronary ischemia (FFRCT≤0.80) in 69% of patients, with severe ischemia (FFRCT≤0.75) in 58%, left main ischemia in 8%, and multivessel ischemia in 40% of patients. The status of coronary ischemia in the control group (n=120) was unknown. Following lower-extremity revascularization, 42% of patients in FFRCT had elective coronary revascularization with no elective revascularization in controls. Both groups received guideline-directed medical therapy. During 5 year follow-up, compared with control, the FFRCT group had fewer all-cause deaths (24% vs 47%, hazard ratio [HR]=0.43 [95% confidence interval [CI]=0.27-0.69], p<0.001), fewer cardiac deaths (5% vs 26%, HR=0.18 [95% CI=0.07-0.45], p<0.001), fewer MIs (7% vs 28%, HR=0.21 [95% CI=0.10-0.47], p<0.001), and fewer MACE events (14% vs 39%, HR=0.28 [95% CI=0.15-0.51], p<0.001).

CONCLUSIONS

Ischemia-guided coronary revascularization of CLTI patients with asymptomatic (silent) coronary ischemia following lower-extremity revascularization resulted in more than 2-fold reduction in all-cause death, cardiac death, MI, and MACE with improved 5 year survival compared with patients with standard cardiac evaluation and care (76% vs 53%, p<0.001).

CLINICAL IMPACT

Silent coronary ischemia in patients with chronic limb-threatening ischemia (CLTI) is common even in the absence of cardiac history or symptoms. FFRCT is a convenient tool to diagnose silent coronary ischemia perioperatively. Our data suggest that post-surgery elective FFRCT-guided coronary revascularization reduces adverse cardiac events and improves long-term survival in this very-high risk patient group. Randomized study is warranted to finally test this concept.

Post hoc analysis of the SuperB and Zilverpass trials for treatment of long and complex superficial femoral artery lesions

OBJECTIVE

In two randomized controlled trials, the outcomes of endovascular treatment of complex femoropopliteal arterial lesions were compared with bypass surgery and considered a valid alternative treatment. The aim of this study was to compare both endovascular treatment options with the hypothesis that implantation of heparin-bonded self-expanding covered stents (Viabahn [SECS]) or drug-eluting stents (ZilverPTX [DES]) are related to similar clinical outcomes at 1-year follow-up.

METHODS

In a post-hoc analysis, the SuperB trial and Zilverpass databases were merged. Patients in the endovascular treatment arms were included, and data was analyzed in an intention-to-treat (ITT) and a per-protocol (PP) fashion. Data included baseline and lesion characteristics, procedural details, and follow-up data. The primary endpoint of this study was primary patency at 1-year follow-up. The secondary endpoints were secondary patency, target lesion revascularization (TLR), limb loss, and all-cause mortality.

RESULTS

A total of 176 patients were included; 63 in the SECS arm and 113 in the DES arm. Through 1-year follow-up, there were no significant differences in primary patency (ITT: 63.4% vs 71.1%: P = .183 and PP: 60.8% vs 71.1%; P = .100). Secondary patency rates were not significantly different in the ITT analysis (86.5% vs 95.1%; P = .054), but in the PP analysis, there was a significant difference in favor of the DES group (SECS, 85.6% vs DES, 95.1%; P = .038). There was no significant difference in freedom from TLR between groups (79.6% vs 77.0%; P = .481). No major amputations were performed in the SECS group, and two were performed in the DES group (1.8%). Survival rate was 98.2% in the SECS group, and 91.3% in the DES group after 1-year follow-up (P = .106). Based on diagnosis (intermittent claudication vs chronic limb-threatening ischemia) no differences between patients with intermittent claudication and chronic limb-threatening ischemia were observed in primary patency, secondary patency and freedom from TLR.

CONCLUSIONS

Treatment of complex femoropopliteal arterial disease with the heparin-bonded Viabahn endoprosthesis and the Zilver PTX drug-eluting stent are related to similar primary and secondary patency, and TLR rates at 1 year, except for secondary patency in the PP analysis. This study further supports the endovascular treatment of long complex lesions in the femoropopliteal artery.

Preoperative Sizing to Lower In-Stent Restenosis in Peripheral Arterial Occlusive Disease

BACKGROUND

The primary treatment for lower-extremity peripheral arterial occlusive disease (PAOD) is angioplasty stenting. Its main complication is in-stent restenosis. Poor selection of stent dimensions has been identified as a factor contributing to early in-stent restenosis. The aim of this study is to determine whether the implantation of stents, selected based on arterial morphological reconstruction using a sizing software program, reduces the occurrence of in-stent restenosis. The study also aims to evaluate the potential benefits of routine preoperative sizing.

METHODS

Between January 2016 and December 2020, all patients treated for PAOD through scheduled angioplasty stenting in our department were included in the study. Using systematic preoperative computed tomography angiography, precise reconstruction and sizing were performed to select the ideal length and diameter of stents, resulting in the selection of a so-called IDEAL stent. During the procedure, the surgeon implanted either the IDEAL stent or a different one, named the ACTUAL stent, based on intraoperative data and/or availability. We compared the in-stent restenosis rate between IDEAL and ACTUAL stents.

RESULTS

There were no significant differences in the overall characteristics between the IDEAL and ACTUAL stent groups. The in-stent restenosis rate at 1 year was 13% (N = 28/212, P = 0.994) in the IDEAL group and 17% (N = 25/149, P = 0.994) in the ACTUAL group. Among the ACTUAL stents, a total of 19.6% of stents with a diameter mismatch when chosen based on arteriography showed a significantly higher restenosis rate during the first year of follow-up (P = 0.02).

CONCLUSIONS

Our study did not demonstrate a significant difference in 1-year restenosis rate between the IDEAL and the ACTUAL stent groups. It specifically revealed the significant impact of diameter selection on the intrastent restenosis rate during the first year of follow-up. Stents chosen based on arteriographic criteria, which exhibited diameter discordance, compared to the IDEAL stents group selected using sizing reconstructions, could be either oversized or undersized. This led to a significantly higher restenosis rate at 1 year postoperatively.

External Validation of the OAC3-PAD Bleeding Score in a Nationwide Population of Patients Undergoing Invasive Treatment for Peripheral Arterial Disease

OBJECTIVE

The OAC3-PAD score was developed to predict bleeding risk in patients with lower extremity peripheral arterial disease (PAD), but its performance in concomitant international cohorts is largely unknown. This study aimed to validate the OAC3-PAD score in an unselected nationwide population of patients undergoing invasive treatment for symptomatic PAD.

METHODS

This was a nationwide cohort study including all patients who underwent a first revascularisation procedure or major amputation for symptomatic PAD in Denmark from 2000 - 2021. The study population was stratified based on OAC3-PAD score, and the one year risk of major bleeding was assessed, accounting for the competing risk of death. The score performance was evaluated using calibration plots, C statistic, Brier score, and the index of prediction accuracy (IPA).

RESULTS

A total of 52 016 patients were included (mean age 71 years, 43.8% female). The one year risk of major bleeding increased with higher OAC3-PAD score, ranging from 1.6% (95% confidence interval [CI] 1.4 - 1.8%) to 2.3% (95% CI 2.0 - 2.5%), 3.5% (95% CI 3.2 - 3.8%), and 5.2% (95% CI 4.8 - 5.6%) for patients with low, low moderate, moderate high, and high score, respectively. Using patients with low risk as reference, the OAC3-PAD score effectively categorised patients, demonstrating statistically significant differences in bleeding risk across strata. However, the score showed modest discriminative performance, with a C statistic of 65% (95% CI 63 - 66%) and a Brier score of 2.6% (95% CI 2.5 - 2.7%). Nevertheless, it performed significantly better than the null model, as indicated by an IPA of 3.1%.

CONCLUSION

Among patients who underwent invasive treatment for symptomatic PAD in routine care, the OAC3-PAD score was associated with greater risk of major bleeding with increasing score level. However, its discriminatory ability was modest, and the clinical utility remains to be determined.

Using Machine Learning (XGBoost) to Predict Outcomes After Infrainguinal Bypass for Peripheral Artery Disease

OBJECTIVE

To develop machine learning (ML) algorithms that predict outcomes after infrainguinal bypass.

BACKGROUND

Infrainguinal bypass for peripheral artery disease carries significant surgical risks; however, outcome prediction tools remain limited.

METHODS

The Vascular Quality Initiative database was used to identify patients who underwent infrainguinal bypass for peripheral artery disease between 2003 and 2023. We identified 97 potential predictor variables from the index hospitalization [68 preoperative (demographic/clinical), 13 intraoperative (procedural), and 16 postoperative (in-hospital course/complications)]. The primary outcome was 1-year major adverse limb event (composite of surgical revision, thrombectomy/thrombolysis, or major amputation) or death. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained 6 ML models using preoperative features. The primary model evaluation metric was the area under the receiver operating characteristic curve (AUROC). The top-performing algorithm was further trained using intraoperative and postoperative features. Model robustness was evaluated using calibration plots and Brier scores.

RESULTS

Overall, 59,784 patients underwent infrainguinal bypass, and 15,942 (26.7%) developed 1-year major adverse limb event/death. The best preoperative prediction model was XGBoost, achieving an AUROC (95% CI) of 0.94 (0.93-0.95). In comparison, logistic regression had an AUROC (95% CI) of 0.61 (0.59-0.63). Our XGBoost model maintained excellent performance at the intraoperative and postoperative stages, with AUROCs (95% CI's) of 0.94 (0.93-0.95) and 0.96 (0.95-0.97), respectively. Calibration plots showed good agreement between predicted and observed event probabilities with Brier scores of 0.08 (preoperative), 0.07 (intraoperative), and 0.05 (postoperative).

CONCLUSIONS

ML models can accurately predict outcomes after infrainguinal bypass, outperforming logistic regression.

Utilization of coronary computed tomography angiography and computed tomography-derived fractional flow reserve in a critical limb-threatening ischemia cohort

Objective

Patients with peripheral arterial disease (PAD) have a significant risk of myocardial infarction and death secondary to concomitant coronary artery disease (CAD). This is particularly true in patients with critical limb-threatening ischemia (CLTI) who exceed a 20% mortality rate at 6 months despite standard treatment with risk factor modification. Although systematic preoperative coronary testing is not recommended for patients with PAD without cardiac symptoms, the clinical manifestations of CAD are often muted in patients with CLTI due to poor mobility and activity intolerance. Thus, the true incidence and impact of "silent" CAD in a CLTI cohort is unknown. This study aims to determine the prevalence of ischemia-producing coronary artery stenosis in a CLTI cohort using coronary computed tomography angiography (cCTA) and computed tomography (CT)-derived fractional flow reserve (FFRCT), a noninvasive imaging modality that has shown significant correlation to cardiac catheterization in the detection of clinically relevant coronary ischemia.

Methods

Patients presenting with newly diagnosed CLTI at our institution from May 2020 to April 2021 were screened for underlying CAD. Included subjects had no known history of CAD, no cardiac symptoms, and no anginal equivalent complaints at presentation. Patients underwent cCTA and FFRCT evaluation and were classified by the anatomic location and severity of CAD. Significant coronary ischemia was defined as FFRCT ≤0.80 distal to a >30% coronary stenosis, and severe coronary ischemia was documented at FFRCT ≤0.75, consistent with established guidelines.

Results

A total of 170 patients with CLTI were screened; 65 patients (38.2%) had no coronary symptoms and met all inclusion/exclusion criteria. Twenty-four patients (31.2%) completed cCTA and FFRCT evaluation. Forty-one patients have yet to complete testing secondary to socioeconomic factors (insurance denial, transportation inaccessibility, testing availability, etc). The mean age of included subjects was 65.4 ± 7.0 years, and 15 (62.5%) were male. Patients presented with ischemic rest pain (n = 7; 29.1%), minor tissue loss (n = 14; 58.3%) or major tissue loss (n = 3; 12.5%). Significant (≥50%) coronary artery stenosis was noted on cCTA in 19 of 24 patients (79%). Significant left main coronary artery stenosis was identified in two patients (10%). When analyzed with FFRCT, 17 patients (71%) had hemodynamically significant coronary ischemia (FFRCT ≤0.8), and 54% (n = 13) had lesion-specific severe coronary ischemia (FFRCT ≤0.75). The mean FFRCT in patients with coronary ischemia was 0.70 ± 0.07. Multi-vessel disease pattern was present in 53% (n = 9) of patients with significant coronary stenosis.

Conclusions

The use of cCTA-derived fractional flow reserve demonstrates a significant percentage of patients with CLTI have silent (asymptomatic) coronary ischemia. More than one-half of these patients have lesion-specific severe ischemia, which may be associated with increased mortality when treated solely with risk factor modification. cCTA and FFRCT diagnosis of significant coronary ischemia has the potential to improve cardiac care, perioperative morbidity, and long-term survival curves of patients with CLTI. Systemic improvements in access to care will be needed to allow for broad application of these imaging assessments should they prove universally valuable. Additional study is required to determine the benefit of selective coronary revascularization in patients with CLTI.

Awareness of smoking cessation amongst German vascular surgeons

Background: Smoking represents the well-known enemy of vascular well-being. Numerous previous studies emphasised the important role of smoking on the development and progression of atherosclerotic cardiovascular disease. The current study aimed to identify hurdles and barriers for an insufficient implementation of secondary prevention in the treatment of lower extremity peripheral arterial disease (PAD). Methods: All members of the German Society for Vascular Surgery and Vascular Medicine (DGG) with valid email addresses were invited to participate in an electronic survey on smoking. Results are descriptively presented. Results: Amongst 2716 invited participants, 327 (12%) submitted complete responses, thereof 33% women and 80% between 30 and 59 years old (87% board certified specialists). 83% were employed by hospitals (56% teaching hospital, 14% university, 13% non-academic) and 16% by outpatient facilities. 6% are active smokers (63% never) while a mean of five medical education activities on smoking cessation were completed during the past five years of practice. Only 27% of the institutions offered smoking cessation programs and 28% of the respondents were aware of local programs while a mean of 46% of their patients were deemed eligible for participation. 63% of the respondents deemed outpatient physicians primarily responsible for smoking cessation, followed by medical insurance (26%). Conclusions: The current nationwide survey of one scientific medical society involved in the care of patients with vascular disease revealed that smoking cessation, although being commonly accepted as important pillar of comprehensive holistic care, is not sufficiently implemented in everyday clinical practice.

Diagnosis of a chronic wound in the special case of a vascular malformation: A proposal of the Wound and Healing Group of the French Society of Vascular Medicine

Vascular malformations can present with a variety of symptoms and an unpredictable course with the occurrence of wounds. Ulcerations in patients with vascular malformations are fortunately rare. Although few data exist, complications may involve a variety of mechanistic or hemodynamic factors. A rigorous etiological and vascular assessment is therefore essential. In view of the paucity of recommendations, the Wound and Healing Group of the French Society of Vascular Medicine, based on the literature on the subject, presents a number of suggestions for the diagnosis and management of wounds associated with vascular malformations.

Patient-specific risk factors for reintervention following primary endovascular treatment of iliac artery disease

OBJECTIVE

Predictive models for reintervention may guide clinicians to optimize selection, education, and follow-up of patients undergoing endovascular iliac revascularization. Although the impact of lesion- and device-related characteristics on iliac restenosis and reintervention risk is well-defined, data on patient-specific risk factors are scarce and conflicting. This study aimed to explore the value of patient-related factors in predicting the need for clinically driven target-vessel revascularization (CD-TVR) in patients undergoing primary endovascular treatment of iliac artery disease.

METHODS

Consecutively enrolled patients undergoing endovascular revascularization for symptomatic iliac artery disease at a tertiary vascular referral center between January 2008 and June 2020 were retrospectively analyzed. Primary and secondary outcomes were CD-TVR occurrence within 24 months and time to CD-TVR, respectively. Patients who died or did not require CD-TVR within 24 months were censored at the date of death or at 730 days, respectively. Multiple imputation was used to account for missing data in primary analyses.

RESULTS

A total of 1538 iliac interventions were performed in 1113 patients (26% females; 68 years). CD-TVR occurred in 108 limbs (74 patients; 7.0%) with a median time to CD-TVR of 246 days. On multivariable analysis, increasing age was associated with lower likelihood of CD-TVR (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.50-0.83; P = .001) and decreased risk of CD-TVR at any given time (hazard ratio [HR], 0.66; 95% CI, 0.52-0.84; P = .001). Similarly, a lower likelihood of CD-TVR (OR, 0.75; 95% CI, 0.59-0.95; P = .017) and decreased risk of CD-TVR at any given time (HR, 0.73; 95% CI, 0.58-0.93; P = .009) were observed with higher glomerular filtration rates. Lastly, revascularization of common vs external iliac artery disease was associated with lower likelihood of CD-TVR (OR, 0.48; 95% CI, 0.24-0.93; P = .030) and decreased risk of CD-TVR at any given time (HR, 0.48; 95% CI, 0.25-0.92; P = .027). No associations were observed between traditional cardiovascular risk factors (sex, hypertension, higher low-density lipoprotein cholesterol, higher hemoglobin A1c, smoking) and CD-TVR.

CONCLUSIONS

In this retrospective cohort study, younger age, impaired kidney function, and external iliac artery disease were associated with CD-TVR. Traditional markers of cardiovascular risk were not seen to predict reintervention.

Five-year outcomes of the GORE VIABAHN Endoprosthesis for the treatment of complex femoropopliteal lesions from a Japanese postmarket surveillance study

Introduction: The safety and effectiveness of the GORE VIABAHN Endoprosthesis for treatment of symptomatic patients with peripheral artery disease (PAD) and complex femoropopliteal (FP) lesions was assessed in a real-world Japanese practice setting. Methods: A prospective, multicenter, postmarket surveillance study was conducted from 2016 to 2017 at 64 sites in Japan. Symptomatic patients with PAD and FP lesions ⩾ 10 cm and reference vessel diameters ranging from 4.0 to 7.5 mm were eligible for enrollment. Outcome measures evaluated at 5 years were primary patency (PP), primary-assisted patency (PAP), secondary patency (SP), freedom from target lesion revascularization (fTLR), occurrence of device- or procedure-related serious adverse events (SAEs), and stent fractures. Results: A total of 321 patients were enrolled and were a mean age of 73.9 ± 8.7 years; 77.3% were men and 26.5% had chronic limb-threatening ischemia (CLTI). The mean lesion length was 23.6 ± 6.6 cm and the frequency with TASC II C/D lesions and chronic total occlusions was 86.6% and 70.4%, respectively. The Kaplan-Meier estimated PP, PAP, SP, and fTLR at 5 years was 62.4%, 74.1%, 82.3%, and 75.9%, respectively. The mean ankle-brachial index was 0.92 ± 0.15 and the mean improvement in Rutherford class was 2.3 ± 1.4, which was maintained through 5 years. The rate of cumulative device- or procedure-related SAEs through 5 years was 19.9% with only 9.3% of those occurring after the first year. No stent fractures were observed through 5 years by x-ray evaluation. Conclusion: The 5-year safety and efficacy outcomes of the endoprosthesis were clinically acceptable for treating complex FP lesions in a real-world cohort of Japanese patients with PAD. (ClinicalTrials.gov Identifier: NCT04706273).

Outcomes of balloon angioplasty and stent placement for iliac artery lesions classified as TASC II A, B: a single-center study

Background

Iliac artery stenosis or occlusion is a critical condition that can severely impact a patient's quality of life. The effectiveness of balloon angioplasty and intraluminal stenting for the treatment of iliac artery lesions classified as TASC II A and B was evaluated in this single-center prospective study.

Methods

Conducted between October 2016 and September 2020 at Cho Ray Hospital's Vascular Surgery Department, this prospective study involved PAD patients categorized by TASC II A and B classifications who underwent endovascular intervention. Intervention outcomes were assessed peri-procedure and during short-term and mid-term follow-ups.

Results

Of the total of 133 patients, 34.6% underwent balloon angioplasty, while 65.4% received stenting. The immediate technical success rate was 97.7%, while the clinical success rate was 62.4%. Complications were minimal, with major limb amputation reported in 1.5% of the cases. There was a significant improvement in Rutherford classification and ABI at short-term follow-up, with a patency rate of 90.2%. The mid-term post-intervention follow-up yielded similar results with an 86.1% patency rate. The mortality rates associated with arterial occlusion were 2.3% during short-term follow-up and 1.7% during mid-term follow-up.

Conclusion

Balloon angioplasty and stent placement are effective and safe interventions for TASC II A and B iliac artery occlusions with favorable short and mid-term outcomes. Further, multi-center studies with larger sample sizes are recommended for more comprehensive conclusions, including long-term follow-up assessment.

Comparative outcomes of aortobifemoral bypass with or without previous endovascular kissing stenting of the aortoiliac bifurcation

OBJECTIVE

The aim of this multicenter national study was to compare the outcomes of primary open surgery by aorto-bifemoral bypass (ABFB) with those performed after a failed endovascular treatment (EVT) by kissing stent technique for complex aortoiliac occlusive disease (AIOD) lesions (TransAtlantic Inter-Society Consensus [TASC] II C and D).

METHODS

All consecutive ABFB cases carried out at 12 vascular surgery centers between 2016 and 2021 were retrospectively collected and analyzed. Data included patients' baseline demographics and clinical characteristics, procedural details, perioperative outcomes, and follow-up results (survival, patency, amputation). The study cohort was divided into two groups based on indications for ABFB: primary treatment vs secondary treatment after EVT failure.

RESULTS

Overall, 329 patients underwent ABFB during the study period (71% males; mean age, 64 years), of which 285 were primary treatment and 44 were after prior EVT. At baseline, no significant differences were found between study groups in demographics and clinical characteristics. TASC C and D lesions were similarly represented in the study groups (TASC C: 22% vs 78%; TASC D: 16% vs 84%). No major differences were found between study groups in terms of procedural details, early mortality, and perioperative complications. At 5 years, primary patency rates were significantly higher for primary ABFB (88%; 95% confidence interval [CI], 93.2%-84%) as compared with ABFB after prior EVT (69%; 95% CI 84.9%-55%; log rank P value < .001); however, the 5-year rates of secondary patency (100% vs 95%; 95% CI, 100%-86%) and limb salvage (97%; 95% CI, 99%-96 vs 97%; 95% CI, 100%-94%) were similar between study groups.

CONCLUSIONS

Surgical treatment of TASC C/D AIOD with ABFB seems to be equally safe and effective when performed after prior EVT, although primary ABFB seemed to have higher primary patency rates. Despite the need for more frequent reinterventions, secondary patency and limb salvage rates were similar. However, future large prospective trials are required to confirm these findings.

Poor short-term outcomes for prognostic high-risk patients with chronic limb-threatening ischemia undergoing endovascular therapy

BACKGROUND

The prognosis of chronic limb-threatening ischemia (CLTI) is poor, with an expected life expectancy of 2 or more years, which significantly influences treatment decisions. However, death may occur at the early stages of treatment for wound healing, and aggressive treatment may limit the quality of life of such patients. In patients with CLTI undergoing endovascular therapy (EVT), the Wound, Ischemia, and foot Infection (WIfI) clinical stage, male sex, older age, non-ambulatory status, low body mass index, and dialysis have been reported as predictors of mortality risk. However, most studies have not fully investigated the WIFI clinical stage as a prognostic predictor of CLTI. This study aimed to evaluate short-term prognosis and wound healing rates using the prognostic predictors (PPs) indicated above in risk-stratified patients with CLTI who underwent EVT.

METHODS

This retrospective single-center observational study included 61 CLTI patients undergoing EVT from April 2020 to October 2022. The patients were divided into a high-risk group (PPs ≥ 4, n = 20) and low-risk group (PPs ≤ 3, n = 41) according to the number of PPs. Survival and wound healing rates within one year were compared between these two groups.

RESULTS

The mean age of the patients was 74.7 ± 1.6 years, and 42 (68.9%) were male. Among these patients, the high-risk group compared with the low-risk group had a significantly worse survival rate within one year (46.4% vs. 84.7%, log-rank p < 0.001). Fifteen patients died within one year. Of these, seven deaths were cardiovascular deaths and six were deaths from infectious diseases. Cox proportional hazards analysis showed that WIfI clinical stage 4 (p = 0.043, hazard ratio [HR] = 4.85) and the male sex (p = 0.037, HR = 6.34) influenced the prognosis of this population. The high-risk group tended to have a worse wound healing rate within one year than that had by the low-risk group (55.4% vs. 83.0%, log-rank p = 0.086).

CONCLUSIONS

The assessment of short-term prognosis and wound healing rates using PPs may be useful. Discussing the results of short-term clinical outcome assessments with patients should be considered when determining their individualized treatment plans.

Safety and effectiveness of the phoenix atherectomy device for endovascular treatment of common femoral and popliteal arteries: Results of the EN-MOBILE trial

Background: This study aimed to assess the peri- and postprocedural outcomes of atherectomy-assisted endovascular treatment of the common femoral (CFA) and popliteal arteries. Methods: Phoenix atherectomy was used for the treatment of 73 and 53 de novo CFA and popliteal artery lesions, respectively, in 122 consecutive patients. Safety endpoints encompassed perforation and peripheral embolization. Postprocedural endpoints included freedom from clinically driven target lesion revascularization (CD-TLR) and clinical success (an improvement of ⩾ 2 Rutherford category [RC]). In addition, 531 patients treated for popliteal artery stenosis or occlusion without atherectomy were used as a comparator group. Results: Procedural success (residual stenosis < 30% after treatment) was 99.2%. The need for bail-out stenting was 2 (2.7%) and 3 (5.7%) in CFA and popliteal artery lesions, respectively. Only one (1.4%) embolization occurred in the CFA, which was treated by catheter aspiration. No perforations occurred. After 1.50 (IQR = 1.17-2.20) years, CD-TLR occurred in seven (9.2%) and six (14.6%) patients with CFA and popliteal artery lesions, respectively, whereas clinical success was achieved in 62 (91.2%) and 31 (75.6%), respectively. Patients treated with atherectomy and DCB in the popliteal artery after matching for baseline RC, lesion calcification, length, and the presence of chronic total occlusion, exhibited higher freedom from CD-TLR compared to the nondebulking group (HR = 3.1; 95% CI = 1.1-8.5, p = 0.03). Conclusion: Atherectomy can be used safely and is associated with low rates of bail-out stenting in CFA and popliteal arteries. CD-TLR and clinical success rates are clinically acceptable. In addition, for the popliteal artery, atherectomy combined with DCB demonstrates lower CD-TLR rates compared to a DCB alone strategy. (German Clinical Trials Register: DRKS00016708).

Machine Learning to Predict Outcomes of Endovascular Intervention for Patients With PAD

Importance

Endovascular intervention for peripheral artery disease (PAD) carries nonnegligible perioperative risks; however, outcome prediction tools are limited.

Objective

To develop machine learning (ML) algorithms that can predict outcomes following endovascular intervention for PAD.

Design, Setting, and Participants

This prognostic study included patients who underwent endovascular intervention for PAD between January 1, 2004, and July 5, 2023, with 1 year of follow-up. Data were obtained from the Vascular Quality Initiative (VQI), a multicenter registry containing data from vascular surgeons and interventionalists at more than 1000 academic and community hospitals. From an initial cohort of 262 242 patients, 26 565 were excluded due to treatment for acute limb ischemia (n = 14 642) or aneurysmal disease (n = 3456), unreported symptom status (n = 4401) or procedure type (n = 2319), or concurrent bypass (n = 1747). Data were split into training (70%) and test (30%) sets.

Exposures

A total of 112 predictive features (75 preoperative [demographic and clinical], 24 intraoperative [procedural], and 13 postoperative [in-hospital course and complications]) from the index hospitalization were identified.

Main Outcomes and Measures

Using 10-fold cross-validation, 6 ML models were trained using preoperative features to predict 1-year major adverse limb event (MALE; composite of thrombectomy or thrombolysis, surgical reintervention, or major amputation) or death. The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). After selecting the best performing algorithm, additional models were built using intraoperative and postoperative data.

Results

Overall, 235 677 patients who underwent endovascular intervention for PAD were included (mean [SD] age, 68.4 [11.1] years; 94 979 [40.3%] female) and 71 683 (30.4%) developed 1-year MALE or death. The best preoperative prediction model was extreme gradient boosting (XGBoost), achieving the following performance metrics: AUROC, 0.94 (95% CI, 0.93-0.95); accuracy, 0.86 (95% CI, 0.85-0.87); sensitivity, 0.87; specificity, 0.85; positive predictive value, 0.85; and negative predictive value, 0.87. In comparison, logistic regression had an AUROC of 0.67 (95% CI, 0.65-0.69). The XGBoost model maintained excellent performance at the intraoperative and postoperative stages, with AUROCs of 0.94 (95% CI, 0.93-0.95) and 0.98 (95% CI, 0.97-0.99), respectively.

Conclusions and Relevance

In this prognostic study, ML models were developed that accurately predicted outcomes following endovascular intervention for PAD, which performed better than logistic regression. These algorithms have potential for important utility in guiding perioperative risk-mitigation strategies to prevent adverse outcomes following endovascular intervention for PAD.

Using machine learning to predict outcomes following suprainguinal bypass

OBJECTIVE

Suprainguinal bypass for peripheral artery disease (PAD) carries important surgical risks; however, outcome prediction tools remain limited. We developed machine learning (ML) algorithms that predict outcomes following suprainguinal bypass.

METHODS

The Vascular Quality Initiative database was used to identify patients who underwent suprainguinal bypass for PAD between 2003 and 2023. We identified 100 potential predictor variables from the index hospitalization (68 preoperative [demographic/clinical], 13 intraoperative [procedural], and 19 postoperative [in-hospital course/complications]). The primary outcomes were major adverse limb events (MALE; composite of untreated loss of patency, thrombectomy/thrombolysis, surgical revision, or major amputation) or death at 1 year following suprainguinal bypass. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained six ML models using preoperative features (Extreme Gradient Boosting [XGBoost], random forest, Naïve Bayes classifier, support vector machine, artificial neural network, and logistic regression). The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). The best performing algorithm was further trained using intra- and postoperative data. Model robustness was evaluated using calibration plots and Brier scores. Performance was assessed on subgroups based on age, sex, race, ethnicity, rurality, median Area Deprivation Index, symptom status, procedure type, prior intervention for PAD, concurrent interventions, and urgency.

RESULTS

Overall, 16,832 patients underwent suprainguinal bypass, and 3136 (18.6%) developed 1-year MALE or death. Patients with 1-year MALE or death were older (mean age, 64.9 vs 63.5 years; P < .001) with more comorbidities, had poorer functional status (65.7% vs 80.9% independent at baseline; P < .001), and were more likely to have chronic limb-threatening ischemia (67.4% vs 47.6%; P < .001) than those without an outcome. Despite being at higher cardiovascular risk, they were less likely to receive acetylsalicylic acid or statins preoperatively and at discharge. Our best performing prediction model at the preoperative stage was XGBoost, achieving an AUROC of 0.92 (95% confidence interval [CI], 0.91-0.93). In comparison, logistic regression had an AUROC of 0.67 (95% CI, 0.65-0.69). Our XGBoost model maintained excellent performance at the intra- and postoperative stages, with AUROCs of 0.93 (95% CI, 0.92-0.94) and 0.98 (95% CI, 0.97-0.99), respectively. Calibration plots showed good agreement between predicted and observed event probabilities with Brier scores of 0.12 (preoperative), 0.11 (intraoperative), and 0.10 (postoperative). Of the top 10 predictors, nine were preoperative features including chronic limb-threatening ischemia, previous procedures, comorbidities, and functional status. Model performance remained robust on all subgroup analyses.

CONCLUSIONS

We developed ML models that accurately predict outcomes following suprainguinal bypass, performing better than logistic regression. Our algorithms have potential for important utility in guiding perioperative risk mitigation strategies to prevent adverse outcomes following suprainguinal bypass.

Safety and efficacy of mechanical aspiration thrombectomy for patients with acute lower extremity ischemia

OBJECTIVE

Acute limb ischemia (ALI) is associated with high rates of amputation and consequent morbidity and mortality. The objective of this study is to report on the safety and efficacy of aspiration thrombectomy using the Indigo Aspiration System in patients with lower extremity (LE) ALI.

METHODS

The STRIDE study was an international, multicenter, prospective, study that enrolled 119 participants presenting with LE-ALI. Patients were treated firstline with mechanical thrombectomy using the Indigo Aspiration System, before stenting or angioplasty, or other therapies as determined by treating physician. The primary end point was target limb salvage at 30 days after the procedure. Secondary end points within 30 days included technical success, defined as core laboratory-adjudicated Thrombolysis in Myocardial Infarction (TIMI) 2/3 flow rate immediately after the procedure, changes in modified Society for Vascular Surgery runoff score, improvement of Rutherford classification compared with before the procedure, patency, rate of device-related serious adverse events, and major periprocedural bleeding. Secondary end points that will be evaluated at 12 months include target limb salvage and mortality.

RESULTS

Of the 119 participants enrolled at 16 sites, the mean age was 66.3 years (46.2% female). At baseline (n = 119), ischemic severity was classified as Rutherford I in 10.9%, Rutherford IIa in 54.6%, and Rutherford IIb in 34.5%. The mean target thrombus length was 125.7 ± 124.7 mm. Before the procedure, 93.0% (of patients 107/115) had no flow (TIMI 0) through the target lesion. The target limb salvage rate at 30 days was 98.2% (109/111). The rate of periprocedural major bleed was 4.2% (5/119) and device-related serious adverse events was 0.8% (1/119). Restoration of flow (TIMI 2/3) was achieved in 96.3% of patients (105/109) immediately after the procedure. The median improvement in the modified Society for Vascular Surgery runoff score (before vs after the procedure) was 6.0 (interquartile range, 0.0-11.0). Rutherford classifications also improved after discharge in 86.5% of patients (83/96), as compared with preprocedural scores. Patency at 30 days was achieved in 89.4% of patients (101/113).

CONCLUSIONS

In the STRIDE (A Study of Patients with Lower Extremity Acute Limb Ischemia to Remove Thrombus with the Indigo Aspiration System) study, aspiration thrombectomy with the Indigo System provided a safe and effective endovascular treatment for patients with LE-ALI, resulting in a high rate (98.2%) of successful limb salvage at 30 days, with few periprocedural complications.

Association Between the Society for Vascular Surgery (SVS)-WIfI (Wound, Ischemia, Foot Infection) Classification, Wagner-Meggitt Classification, and Amputation Rate in Patients With Diabetic Foot Infection

Diabetic foot infection (DFI) is a common problem in patients with diabetic foot disease. Amputations and other complications of DFI lead to significant morbidity and mortality. The Society for Vascular Surgery (SVS)-WIfI (wound, ischemia, and foot infection) classification system can evaluate the benefit from revascularization and the risk of amputation in 1 and 3 years. We aimed to evaluate SVS-WIfI and Wagner-Meggitt (WM) prediction of DFI outcome, and to determine factors associated with major amputation and mortality rate. The patients with diabetes who presented between June 2018 and May 2020 with characteristics suggesting a more serious DFI or potential indications for hospitalization were reviewed in this cohort study. Demographic data, clinical characteristics, and type of revascularization were evaluated. One-year and 3-year amputation and mortality rates were the main outcomes. The grading of WM classification and the SVS-WIfI score were compared between amputation and nonamputation groups. Association between mortality and comorbidity were analyzed. One hundred and thirty-one patients admitted with DFI were included in study. And 73.28% had peripheral arterial disease (PAD). The 1-year and 3-year major amputation rates were 16.03% and 26.23%, respectively. Seventy-eight (59.54%) patients required minor amputation to control infection before revascularization. PAD (risk ratio [RR] 1.47: 95% confidence interval [CI] 1.29-1.67, P = .032), benefit from revascularization clinical stage 3 on SVS-WIfI score (RR 4.56: 95%CI 1.21-17.21, P = 0.007), and high WM classification score (RR 9.46: 95% CI 5.65-15.82, P < 0.001) were associated by multivariate analysis with high amputation rates. 1-year & 3-year amputation risk on SVS-WIfI score were not associated with amputation rates in DFI (P = .263 and .496). Only 9 (6.8%) patients were lost to follow up during the 3-year period. WM classification score, SVS-WIfI score on benefit from revascularization, and PAD were strongly associated with major amputation rates in patients with DFI.

Supervised Exercise Therapy for Intermittent Claudication: A Propensity Score Matched Analysis of Retrospective Data on Long Term Cardiovascular Outcomes

OBJECTIVE

This study aimed to explore the long term outcomes of patients with intermittent claudication (IC) who completed supervised exercise therapy (SET) vs. those who declined or prematurely discontinued SET, focusing on the incidence of chronic limb threatening ischaemia (CLTI), revascularisation, major adverse limb events (MALE), and major adverse cardiovascular events (MACE).

METHODS

A retrospective registry analysis of consecutive patients with IC who were referred for SET between March 2015 and August 2016 and followed up for a minimum of five years. Serial univariable analysis and logistic regression were performed to identify the statistically significant clinical variables that were independent predictors of each outcome measure. The resulting statistically significant variables were used to guide 1:1 propensity score matching (PSM) using the nearest neighbour method with a calliper of 0.2. Cox proportional hazards regression was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for the association between SET and the outcomes of interest.

RESULTS

Two hundred and sixty-six patients were referred to SET between March 2015 and August 2016. Of these, 64 patients completed SET and 202 patients did not. After PSM, 49 patients were analysed in each cohort. The Cox proportional hazards analysis revealed a significant association between completion of SET and revascularisation requirement (HR 0.46 95% CI 0.25 - 0.84; p = .011), completion of SET and progression to CLTI (HR 0.091, 95% CI 0.04 - 0.24; p < .001), completion of SET and MACE (HR 0.52; 95% CI 0.28 - 0.99; p = .05) and completion of SET and MALE (HR 0.28, 95% CI 0.13 - 0.65; p = .003). The Harrell's C index for all of these models was greater than 0.75, indicating good predictive accuracy.

CONCLUSION

Completion of SET is associated with better outcomes in patients who completed SET compared with patients who declined or discontinued SET with respect to clinically important cardiovascular outcomes over seven years.

Successful Revascularization, Angiosome Concept, and Multivessel Revascularization: Effects on Wound Healing: An Asian Perspective

Endovascular treatment for revascularization in patients with chronic limb-threatening ischemia (CLTI), which is commonly found in patients with diabetes mellitus demonstrates a variable result of vessel patency, wound healing rate, and limb salvage rate. The angiosome concept has been adopted to determine the best target arterial path (TAP) for revascularization for wound healing in CLTI patients. Recent publications demonstrated the benefit of angiosome-targeted revascularization to guide the endovascular treatment in patients CLTI. The best TAP under angiosome concept by direct revascularization with at least 2 of 3 below-the-knee arteries runoff to restore in-line pulsatile blood flow to the ischemic tissue shows the best patency and high rate of wound healing. However, the clinical evidence and application of the angiosome concept in daily practice are difficult and not well established. The vascular territories, collateral vessel, wound area, and locations which associated with angiosome are varied. This article review aims to summarize the concept of angiosome-targeted revascularization and multivessel revascularization for application to the real-world practice under the evidence-based data.

Pharmacomechanical thrombectomy with Angiojet in acute arterial occlusions: A prospective study among the results and outcomes

OBJECTIVE

The main objective of this present paper was to evaluate the results and outcomes of patients with acute limb ischemia (ALI) submitted to pharmacomechanical thrombectomy (PMT) endovascular surgery with Angiojet, regarding the number of cycles/pumps.

METHODS

Prospective, consecutive cohort study of ALI patients submitted to PMT endovascular intervention subdivided into two groups according to the number of cycles in the Angiojet technique: Group 1 higher than 150 cycles/second and Group 2 lesser than 150 cycles/second (cycles/s).

RESULTS

Overall, 92 patients with ALI submitted to PMT were evaluated. Two groups of patients were identified: Group 1 higher than 150 cycles/s with 60 patients and Group 2 lesser than 150 cycles/s with 32 patients. The overall mortality rate (OMR) was 15.1% (13 patients) in total cohort within the first 30 days. Group 1 had a higher OMR than Group 2 (16.1% vs 9.3%, p = 0.007). There were 4 cases of hematuria (4.3%), all of them in Group 1. We have performed a Kaplan-Meier regarding limb salvage rates: Group 1 had 85% and Group 2 had 95.7% at 1057 days. P = 0.081. Among the factors evaluated, the following were related to overall mortality rate: PMT with higher >150 cycles/s (HR = 7.17, p = 0.007, CI: 1.38-8.89), COVID-19 infection (HR = 2.75, p = 0.010, CI = 1.73-5.97), and post-operative acute kidney injury (HR = 2.97, p < 0.001, CI = 1.32-8.13). Among the factors evaluated, the following was related to limb loss: post-operative acute kidney injury (HR = 4.41, p = 0.036, CI: 1.771-7.132), probably because patients experiencing limb loss have a higher incidence of acute renal insufficiency due to higher circulating myoglobin higher hemolysis from the increased Angiojet cycles inducing rhabdomyolysis.

CONCLUSION

PMT with Angiojet is a safe and effective therapy in patients with ALI. However, patients receiving greater than 150 cycles/s were noted to have higher rates of acute kidney injury and mortality. This is likely reflective of increased thrombus burden and higher rates of hemolysis. Acute kidney injury, greater than 150 cycles/s, and COVID-19 infection were the variables with the strongest association to perioperative mortality.

Use of Rotational Atherectomy-Assisted Balloon Angioplasty in the Treatment of Isolated Below-the-Knee Atherosclerotic Lesions in Patients with Chronic Limb-Threatening Ischemia

The aim of the study is to evaluate the safety and effectiveness of rotational atherectomy-assisted balloon angioplasty (BTK-RA) for the treatment of isolated below the knee (BTK) atherosclerotic lesions and to compare the outcomes to plain old balloon angioplasty (POBA). Between January 2020 and September 2023, 96 consecutive patients with chronic limb threatening ischemia (CTLI) and isolated BTK-lesions underwent POBA (group A) or BTK-RA (group B). The primary outcome measures were: periprocedural technical success, primary patency, postoperative increase of the ankle branchial index (ABI), target lesion revascularization (TLR), limb salvage, minor amputation and death. Both techniques had similar technical success, operative time, intraprocedural complications and bailout stent implantations, independently of the operator's experience. Group B had significantly higher primary patency rates (93.5% vs. 72.0%, respectively, p = 0.006), TLR (2.1% vs. 24%, p = 0.057), lower in-hospital stay (2.0-3.0 vs. 4.0-6.0 days, respectively, p < 0.001) and higher postoperative ABI (0.8-0.2 vs. 0.7-0.1, respectively, p = 0.008), compared to group A. Significant differences (POBA n: 20, 40%, BTK-RA n = 3, 6.5%) were found in minor amputation rates between the two groups (p < 0.001), while the respective limb salvage rates were similar in both groups (94.0% vs. 97.8%, p = 0.35). The use of BTK-RA for the treatment of BTK-lesions in patients with CTLI showed significant clinical advantages in comparison to POBA.

Predictors of Crossing Failure in Femoropopliteal Lesions: The Importance of Length of the Lesion and Calcification

BACKGROUND

Endovascular therapy is nowadays the first choice for most patients with peripheral artery disease. The most important cause of technical failure is failure to cross the lesion with a wire. In this retrospective study, we explore possible risk factors of crossing failure.

METHODS

We included all consecutive patients in whom the lesion could not be crossed in the period of the January 1, 2017-January 1, 2022. The lesions of these patients were compared with patients in whom the lesion could be crossed (2:1). The following potential anatomical risk factors were compared: location of the lesion, occlusion length, lesion length, Peripheral Arterial Calcium Scoring Scale, Peripheral Academic Research Consortium, circumferential characterization classification, and the Trans-Atlantic Inter-Society Consensus II classification.

RESULTS

In 71 patients, the lesion could not be crossed; these patients were compared with 142 patients. There were significantly more patients with hypertension and hyperlipidemia in the group with crossing failure. The following factors were risk factors for crossing failure: occlusion length, lesion length, Peripheral Arterial Calcium Scoring Scale, Peripheral Academic Research Consortium, and circumferential characterization classification.

CONCLUSIONS

Although conclusions should be carefully drawn from this retrospective study, calcification and length of the lesion are associated with crossing failure in the femoropopliteal segment. The Trans-Atlantic Inter-Society Consensus II classification was the best predictor of crossing failure.