The Reintervention Index: A New Outcome Measure for Comparative Effectiveness of Lower Extremity Revascularization

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.

Clinical Impact of an Enhanced Recovery Program for Lower-extremity Bypass

OBJECTIVE

To determine the association of Enhanced Recovery Program (ERP) implementation with length of stay (LOS) and perioperative outcomes after lower-extremity bypass (LEB).

BACKGROUND

ERPs have been shown to decrease hospital LOS and improve perioperative outcomes, but their impact on patients undergoing vascular surgery remains unknown.

METHODS

Patients undergoing LEB who received or did not receive care under the ERP were included; pre-ERP (January 1, 2016-May 13, 2018) and ERP (May 14, 2018-July 31, 2022). Clinicopathologic characteristics and perioperative outcomes were analyzed.

RESULTS

Of 393 patients who underwent LEB [pre-ERP: n = 161 (41%); ERP: n = 232 (59%)], most were males (n = 254, 64.6%), White (n = 236, 60%), and government-insured (n = 265, 67.4%). Pre-ERP patients had higher Body Mass Index (28.8 ± 6.0 vs 27.4 ± 5.7, P = 0.03) and rates of diabetes (52% vs 36%, P = 0.002). ERP patients had a shorter total [6 (3-13) vs 7 (5-14) days, P = 0.01) and postoperative LOS [5 (3-8) vs 6 (4-8) days, P < 0.001]. Stratified by indication, postoperative LOS was shorter in ERP patients with claudication (3 vs 5 days, P = 0.01), rest pain (5 vs 6 days, P = 0.02), and tissue loss (6 vs 7 days, P = 0.03). ERP patients with rest pain also had a shorter total LOS (6 vs 7 days, P = 0.04) and lower 30-day readmission rates (32%-17%, P = 0.02). After ERP implementation, the average daily oral morphine equivalents decreased [median (interquartile range): 52.5 (26.6-105.0) vs 44.12 (22.2-74.4), P = 0.019], while the rates of direct discharge to home increased (83% vs 69%, P = 0.002).

CONCLUSIONS

This is the largest single-center cohort study evaluating ERP in LEB, showing that ERP implementation is associated with shorter LOS and improved perioperative outcomes.

Insulin Requirement and Infrainguinal Bypass Outcomes in Patients with Peripheral Arterial Disease

BACKGROUND

Diabetes mellitus (DM) is a major risk factor for peripheral artery disease. The association of DM with major adverse limb events (MALE) after lower extremity revascularization remains controversial, as patients with diabetes are typically analyzed as a single, homogenous group. Using a large national database, this study examines the impact of insulin use and glycemic control on the outcomes following infrainguinal bypass. The hypothesis is that prevalent insulin therapy and elevated hemoglobin A1c (HbA1c) are associated with an increased risk of MALEs after infrainguinal bypass in patients with DM and could therefore be used for risk stratification.

METHODS

The Vascular Quality Initiative database files for infrainguinal bypass (2007-2021) were retrospectively reviewed. Patients with DM undergoing bypass for peripheral artery disease were included. Patients on dialysis or with prior kidney transplantation were excluded. The characteristics and outcomes of patients with insulin-requiring diabetes mellitus (IRDM) were compared to those of patients not requiring insulin (noninsulin-requiring diabetes mellitus [NIRDM]) prior to the bypass procedure.

RESULTS

A total of 9,686 patients with DM (56% IRDM) underwent bypass. Patients with IRDM were significantly younger than patients with NIRDM, more likely to be female (P < 0.01), African American (P < 0.01), and Hispanic (P = 0.031), and more likely to have comorbidities and be categorized into American Society of Anesthesiologist classes IV-V. They were more likely to be treated for chronic limb-threatening ischemia (P < 0.001). Patients with IRDM had significantly higher perioperative complications with no difference in perioperative mortality between the 2 groups. Beyond the perioperative period, with a mean follow-up of 427 days, patients with IRDM had significantly lower crude rates of primary patency and higher crude rates of major amputation, MALE, and mortality compared to patients with NIRDM. Regression analyses demonstrated that insulin requirement, but not HbA1c, was independently associated with a higher risk of MALE (hazard ratio = 1.17 [1.06-1.29]) and mortality (hazard ratio = 1.28 [1.16-1.43]).

CONCLUSIONS

Insulin requirement, but not HbA1c, is significantly associated with MALEs and survival after infrainguinal bypass in the Vascular Quality Initiative. Stratification of patients with DM based on their prevalent insulin use prior to infrainguinal bypass surgery could improve the prediction of outcomes of peripheral arterial bypass surgery in patients with diabetes.

Perioperative complications of minor and major reinterventions for peripheral arterial disease

INTRODUCTION

Patients with peripheral arterial disease (PAD) frequently require reinterventions after lower-extremity revascularization (LER) to maintain perfusion. Current Society for Vascular Surgery guidelines define reinterventions as major or minor based on the magnitude of the procedure. While prior studies have compared primary LER procedures of different magnitudes, similar studies for reinterventions have not been performed. The objective of this study is to compare perioperative outcomes associated with major and minor reinterventions.

METHODS

Patients undergoing LER for PAD at a tertiary care center from 2013 to 2017 were included. A retrospective review of electronic medical records was performed, and reinterventions were categorized as major or minor based on the procedure magnitude. Minor reinterventions included endovascular procedures and open revision with patch angioplasty, while major reinterventions were characterized by open surgical or endovascular LER with catheter-directed thrombolysis (CDT). Perioperative outcomes following LER were captured and compared for major and minor reinterventions. An additional subgroup analysis was performed comparing outcomes associated with major reinterventions stratified into open major surgical reinterventions and CDT.

RESULTS

This study included 713 patients over a mean follow-up of 2.5 years. A total of 291 patients underwent 696 ipsilateral reinterventions (range = 1-12 reinterventions). Most reinterventions were minor (72.1%, N = 502) and 27.9% (N = 194) were major. Patients receiving reinterventions had an average age of 67.2 ± 11.5 and most were white (73.5%) males (60.1%) initially treated for claudication (58.2%) and CLTI (41.8%). There was significantly higher post-operative bleeding (9.8% vs 3.4%, p = .001), arterial thrombosis (3.1% vs 1.0%, p = .047), and acute renal failure (6.2% vs 2.4%, p = .014) after major reinterventions than minor. Additionally, major reinterventions had significantly higher return to the OR (17.0% vs 11.3%, p = .046) and longer hospital stays (7.5 vs 4.3 days, p = <.0001). Overall, major reinterventions were associated with significantly increased perioperative morbidity (37.6% vs 19.7%, p ≤ .001) with no difference in perioperative mortality. In the subgroup analysis, open reinterventions resulted in significantly longer hospital stays (8.6 days vs 5.5 days, p ≤ .001) and more wound infections than CDT (11.0% vs 0%, p = .017). However, there was no other significant difference in morbidity or mortality following treatment with open surgical reinterventions or CDT.

CONCLUSIONS

In this study, major reinterventions after LER were associated with greater perioperative morbidity than minor reinterventions, with no difference in mortality. Major reinterventions performed via open surgery and CDT had similar morbidity and mortality.

The Use and Impact of Cilostazol on Patients Undergoing Endovascular Peripheral Interventions

OBJECTIVES

Cilostazol is used for the treatment of intermittent claudication. The impact of cilostazol on the outcomes of peripheral vascular interventions (PVI) remains controversial. This study assesses the use and impact of cilostazol on patients undergoing PVI for peripheral arterial disease (PAD).

METHODS

The Vascular Quality Initiative (VQI) database files for PVI were reviewed. Patients with PAD who underwent PVI for CLTI or claudication were included and divided based on the use of cilostazol preoperatively. After propensity matching for patient demographics and comorbidities, the short-term and long-term outcomes of the two groups (preoperative cilostazol use versus no pre-operative cilostazol use) were compared. The Kaplan-Meier method was used to determine outcomes.

RESULTS

A total of 245,309 patients underwent PVI procedures and 6.6% (N=16,366) were on cilostazol prior to intervention. Patients that received cilostazol were more likely to be male (62% vs 60%; P < .001), White (77% vs 75%; P < .001), and smokers (83% vs 77%; P < .001). They were less likely to have diabetes mellitus (50% vs 56%; P < .001) and congestive heart failure (14% vs 23%; P < .001). Patient on cilostazol were more likely to be treated for claudication (63% vs 40%, P < .001), undergo prior lower extremity revascularization (55% vs 51%, P<.001) and less likely to have undergone prior minor and major amputation (10% vs 19%; P < .001) compared to patients who did not receive cilostazol. After 3:1 propensity matching, there were 50,265 patients included in the analysis with no differences in baseline characteristics. Patients on cilostazol were less likely to develop renal complications and more likely to be discharged home. Patients on cilostazol had significantly lower rates of long-term mortality (11.5% vs 13.4%, P <.001 and major amputation (4.0% vs 4.7%, P=0.022). However, there were no significant differences in rates of reintervention, major adverse limb events, or patency after PVI. Amputation-free survival rates were significantly higher for patients on cilostazol, after four years of follow-up (89% vs 87%, P=0.03).

CONCLUSION

Cilostazol is underutilized in the VQI database and seems to be associated with improved amputation-free survival. Cilostazol therapy should be considered in all patients with PAD who can tolerate it prior to PVI.

A narrative review on the application of high-intensity focused ultrasound for the treatment of occlusive and thrombotic arterial disease

Objectives

High-intensity focused ultrasound (HIFU) is a noninvasive therapeutic modality with a variety of applications. It is approved for the treatment of essential tremors, ablation of prostate, hepatic, breast, and uterine tumors. Although not approved for use in the treatment of atherosclerotic arterial disease, there is a growing body of evidence investigating applications of HIFU. Currently, percutaneous endovascular techniques are predominant for the treatment of arterial pathology; however, there are no endovascular techniques of HIFU available. This study aims to review the state of current evidence for the application of HIFU in atherosclerotic arterial disease.

Methods

All English-language articles evaluating the effect of HIFU on arterial occlusive and thrombotic disease until 2021 were reviewed. Both preclinical and human clinical studies were included. Study parameters such as animal or clinical model and outcomes were reviewed. In addition, details pertaining to settings on the HIFU device used were also reviewed.

Results

In preclinical models, atherosclerotic plaque progression was inhibited by HIFU, through decreases in oxidized low-density lipoprotein cholesterol and increases in macrophage apoptosis. Additionally, HIFU promotes angiogenesis in hindlimb ischemic models by the upregulation of angiogenic and antiapoptotic factors, with increased angiogenesis at higher line densities of HIFU. HIFU also promotes thrombolysis and conversely induces platelet activation at low frequencies and higher intensities. Various clinical studies have attempted to translate some of these properties and demonstrated positive clinical outcomes for arterial recanalization after thrombotic stroke, decreased atherosclerotic plaque burden in carotid arteries, increase in tissue perfusion and a decrease in diameter stenosis in patients with atherosclerotic arterial disease.

Conclusions

In current preclinical and clinical data, the safety and efficacy of HIFU shows great promise in the treatment of atherosclerotic arterial disease. Future focused studies are warranted to guide the refinement of HIFU settings for more widespread adoption of this technology.

The Impact of Clinical Follow-Up After Revascularization on the Outcomes of Patients with Chronic Limb Threatening Ischemia

BACKGROUND

Guidelines for optimal follow-up for patients undergoing lower extremity revascularization (LER) for peripheral arterial disease recommend multiple visits with imaging during the first year followed by yearly monitoring thereafter. Critical limb-threatening ischemia (CLTI) patients are at a greater risk for mortality and limb amputation than claudicants and thus necessitate closer monitoring. The goal of this article is to study the effects of compliance with follow-up after revascularization for patients with CLTI on major amputation rates and mortality.

METHODS

A single-center retrospective chart review of consecutive patients undergoing LER for CLTI was performed. Patients were stratified based on compliance with follow-up to compliant or noncompliant cohorts. Patient characteristics, reinterventions, and perioperative and long-term outcomes were compared between the 2 groups.

RESULTS

There were 356 patients undergoing LER and 61% (N = 218) were compliant. There was no significant difference in baseline characteristics between the 2 groups. Noncompliant patients were more likely to undergo endovascular interventions compared to compliant patients (92.8% vs. 79.4%, P = 0.03). There was no difference in perioperative outcomes between the 2 groups with overall 30-day mortality of 0.6%. After mean follow-up of 2.7 years, compliant patients had greater ipsilateral reintervention rates (49.1% vs. 34.1%, P = 0.005) and overall reintervention rates (61% vs. 44.2%, P = 0.002) compared to noncompliant patients. There was no significant difference in mortality or ipsilateral major amputations between the 2 groups.

CONCLUSIONS

Patients who were compliant with follow-up after LER for CLTI underwent more reinterventions with no difference in mortality or major limb amputation. Further research regarding the threshold for reintervention and the optimal schedule for follow-up in patients with CLTI is needed.

Eligibility of Patients with Chronic Limb Threatening Ischemia for Deep Venous Arterialization

OBJECTIVES

Percutaneous deep venous arterialization (pDVA) has emerged as a new modality for limb salvage in patients with chronic limb threatening ischemia (CLTI) and no standard option for revascularization. The proportion of patients facing major amputation that are eligible for this technology remains unknown. This study aims to provide a real-life estimate of patient eligibility for pDVA to reduce major amputations.

METHODS

Electronic medical records of 100 consecutive patients with peripheral arterial disease (PAD) who underwent major amputation of 106 limbs were reviewed. Angiograms performed ≤6 months before amputation were assessed by two vascular surgeons. Disease severity was categorized using the Global Limb Anatomic Staging System and patients were classified as ideal, possible, or not candidates for pDVA. Ideal candidates had ≥1 patent tibial artery, no target in the foot, and no proximal disease. Possible candidates had ≥1 patent tibial artery with PAD, no target in the foot, and proximal disease amenable to endovascular therapy. Patients were not eligible if there was no patent tibial artery, extensive PAD, or an arterial target in the foot for bypass.

RESULTS

Of 106 limbs reviewed, 35 (33%) did not undergo angiography ≤6 months before amputation because of infection (n=14), advanced tissue loss (n=10), failed revascularizations (n=8), advanced limb ischemia (n=2), and refusing revascularization (n=1). Thus, 69 lower extremity angiograms (2 incomplete excluded) in 68 patients were analyzed. 15 patients with 16 limbs (23.2%) were identified as candidates for pDVA (ideal=7, possible=9). There were no differences in demographics between the two groups, but candidates for pDVA were less likely to have hyperlipidemia and congestive heart failure than those who were not candidates. pDVA candidates underwent significantly fewer interventions prior to major amputation compared to patients who were not candidates (1.50 ± 0.73 vs 2.61 ± 2.57, p=0.007). Angiographically, patients who were pDVA candidates had significantly higher Inframalleolar GLASS grades (1.81 ± 0.40 vs 0.86 ± 0.41, p<0.0001) but lower Femoropopliteal Glass grades (0.73 ± 1.10 vs 2.43 ± 1.71, p<0.0001) than patients who were not candidates. There was no significant difference in GLASS stage between these two groups (p=0.368). After mean follow-up of 48 months, there was no difference in mortality between both groups (40% vs 32.1%, p=0.567).

CONCLUSION

Among patients considered for revascularization, 23.2% had favorable angiography and 14.7% could have benefited for pDVA as a new therapeutic modality for limb salvage. 33% of major amputations were performed for clinically-deemed unsalvageable CLTI.

Reinterventions in Patients with Claudication and Chronic Limb Threatening Ischemia

BACKGROUND

Patients with peripheral artery disease (PAD) present with claudication or chronic limb threatening ischemia (CLTI). CLTI patients have a more advanced stage of atherosclerosis and increased comorbidities compared to claudicants, and are at an elevated risk of major amputation and mortality after lower extremity revascularization (LER). However, the frequency of reinterventions for claudication and CLTI have not been compared. Our hypothesis is that patients with CLTI undergo more frequent reinterventions to prevent major amputation.

METHODS

A single-center retrospective chart review of consecutive patients undergoing lower extremity revascularization (LER) for PAD in 2013-2015 was performed. Patients were stratified based on indication for revascularization into claudication or CLTI. Patient characteristics, outcomes, and reinterventions were compared between the 2 groups.

RESULTS

There were 826 patients undergoing LER and 44% (N = 361) had CLTI. Patients treated for CLTI were more likely to be smokers (P < 0.001), to have diabetes (P< 0.001), chronic renal insufficiency (P< 0.001), end stage renal disease (P< 0.001), and cardiac disease (P< 0.001). CLTI patients were less likely to be on optimal medical management as reflected by decreased rate of aspirin (P< 0.001), ADP receptor/P2Y12 inhibitors (P< 0.001), and statins (P< 0.001) compared to patients with claudication. Patients with CLTI had significantly higher major amputation (3.7% vs. 0.2%, P< 0.001) and mortality (1.4% vs. 0.2%, P = 0.092) at 30 days. At long-term follow up, patients with CLTI had higher rates of major amputation (15.5% vs. 1.3%, P < 0.001) and mortality (37.1% vs. 18.1%, P < 0.001) compared to patients with claudication. There was a significant difference in mean follow-up time between the 2 cohorts (claudication: 3.7 ± 1.5 years versus CLTI: 2.6 ± 1.8 years, P < 0.001). There was no significant difference in the ipsilateral reintervention rate between the 2 groups (claudication: 39.6% vs. CLTI: 42.7%, P = 0.37) or the mean number of ipsilateral reinterventions (claudication: 2.0 ± 1.6 vs. CLTI: 2.0 ± 1.7). However, after adjusting for follow-up time, the mean number of reinterventions per year was significantly higher for CLTI patients compared to patients with claudication (1.4 ± 2.2 vs. .6 ± 0.7 intervention per year, P < 0.001).

CONCLUSIONS

Patients undergoing LER for CLTI undergo more frequent reinterventions over time compared to patients treated for claudication. Research on reinterventions after LER should include reporting of the frequency of reintervention adjusted for the follow up period in addition to the reintervention rate defined as the percentage of patients undergoing reintervention.

Outcomes of bypass and endovascular interventions for advanced femoropopliteal disease in patients with premature peripheral artery disease

OBJECTIVE

Patients with premature peripheral artery disease (PAD), defined as age ≤50 years at presentation, have had poor outcomes with open and endovascular lower extremity revascularization. It is unclear whether either strategy is associated with better outcomes because comparative studies have been limited to case series in this patient population. The aim of the present study was to compare the outcomes of patients with premature PAD who had undergone bypass or endovascular revascularization for advanced femoropopliteal disease. Our hypothesis was that open bypass would provide superior long-term outcomes compared with endovascular intervention for patients with premature advanced femoropopliteal PAD.

METHODS

All the patients with premature PAD who had undergone isolated femoropopliteal lower extremity revascularization and included in the Vascular Quality Initiative infrainguinal bypass and peripheral vascular intervention files were reviewed from 2003 through 2019. Propensity score matching (1:1) was performed between patients who had undergone femoropopliteal bypass and endovascular interventions for isolated femoropopliteal Trans-Atlantic Classification System C or D lesions. The 1-year outcomes, including reintervention, patency, major amputation, and mortality, were analyzed.

RESULTS

Of the 2538 included patients, 902 had undergone isolated femoropopliteal endovascular intervention and 1636 had undergone femoropopliteal bypass. The endovascular intervention group were more likely to have diabetes (68.9% vs 54.0%; P < .001), coronary artery disease (31.0% vs 23.0%; P < .001), renal failure requiring dialysis (14.2% vs 7.2%; P < .001), and claudication (45.1% vs 36.6%; P < .001) compared with the bypass group. After propensity score matching, 466 patients were in each group with no significant differences in the baseline characteristics. Perioperative morbidity was higher with femoropopliteal bypass compared with endovascular intervention (12.0% vs 7.9%; P = .038); however, the rates of major amputation and mortality were not different. At 1 year, patients who had undergone femoropopliteal bypass were less likely to require reintervention (17.0% vs 25.2%; P = .012). However, no differences were found in major amputation (7.7% vs 7.9%; P = .928) or mortality (5.2% vs 5.2%; P = 1.00). Propensity score matching was also performed between femoropopliteal bypass with the great saphenous vein and isolated femoropopliteal endovascular interventions, and the outcomes were similar.

CONCLUSIONS

For patients with premature PAD and advanced femoropopliteal disease, bypass surgery decreased the reintervention rate at 1 year but was associated with increased perioperative morbidity and hospital length of stay compared with endovascular therapy. No differences were found in major amputation or mortality between the two strategies.