Impact of calcification and infrapopliteal outflow on the outcome of endovascular treatment of femoropopliteal occlusive disease

Incidence of Acute Thrombotic Occlusion and Its Predictors After Contemporary Femoropopliteal Endovascular Therapy in Patients With Peripheral Artery Disease

PURPOSE

This study investigated the incidence of acute thrombotic occlusion (ATO) and its predictors after contemporary femoropopliteal (FP) endovascular therapy (EVT) for peripheral artery disease.

MATERIALS AND METHODS

We retrospectively examined 763 limbs (chronic limb-threatening ischemia [CLTI]: 44%, involving popliteal lesion: 44%) in 644 patients (mean age: 75±9 years, male: 71%, hemodialysis: 34%) who successfully underwent EVT with contemporary FP devices (drug-coated stent: n=220, stent graft: n=158, drug-eluting stent: n=150, drug-coated balloon [DCB]: n=235) from June 2012 to July 2020. The outcome measure was ATO defined as acute onset of claudication and/or signs of CLTI in combination with angiographic evidence of occlusive thrombus formation within the treated segment. Cox proportional hazards regression models were used to identify baseline characteristics associated with the incidence of ATO after EVT treated with scaffold. To determine the impact of ATO occurrence and creatine phosphokinase (CPK) elevation on the subsequent composite outcome of mortality or major amputation, we developed the Cox model in which the trichotomous variable (free from ATO, ATO without CPK elevation, and ATO with CPK elevation) was a time-dependent covariate.

RESULTS

The 24-month incidence of ATO in the overall population was 4.3%±0.8% (DCB: 1.0%±0.7% vs scaffold: 5.8%±1.1%, p<0.01). Hemodialysis (hazard ratio [HR]: 2.63, p=0.02) and involving popliteal lesion (HR: 8.22, p<0.01) were independently associated with an increased risk of ATO in patients treated with scaffold. Both ATO without CPK elevation and ATO with CPK elevation were significantly associated with a composite outcome of mortality or major amputation comparing free from ATO, with an HR of 2.39 and 9.87, respectively (p=0.02 and p<0.01).

CONCLUSION

We found a substantial incidence of ATO after contemporary FP-EVT, particularly with scaffold. Hemodialysis and involving popliteal lesion were significantly associated with ATO risk in patients treated with scaffold. The occurrence of ATO, particularly with CPK elevation, was associated with an increased risk of a subsequent composite outcome of mortality or major amputation. The scaffold was safely used in patients without those risk factors of ATO, but a non-scaffolding strategy should be considered for patients with more risk factors.

CLINICAL IMPACT

The scaffold was safely used in patients without hemodialysis and involving popliteal lesion, but a non-scaffolding strategy should be considered for patients with those risk factors. The occurrence of ATO, particulary with CPK elevation, was of high risk of mortality or amputation.

Specialty Balloons for Vessel Preparation During Infrainguinal Endovascular Revascularization Procedures: A Review of Literature

Balloon angioplasty with/without utilizing drug eluting technology or stenting constitutes the treatment of choice for a significant percentage of patients with peripheral artery disease requiring an intervention. However, in cases of diffuse disease and plaque complexity, angioplasty may lead to dissection, recoil, and/or early restenosis, making vessel preparation a key component for successful and durable endovascular revascularization outcome. This review of literature aims to present contemporary data for several commercially available specialty balloons that have been designed to minimize the arterial wall stress of conventional balloon angioplasty and facilitate technical success, as well as long-term patency.

Results of New Dual-Drug Coated Balloon Angioplasty versus POBA for Femoropopliteal Lesions

BACKGROUND

The study aimed to assess the 24-month safety and effectiveness of a new generation drug-coated balloon (DCB) (Elutax; AR Baltic Medical, Vilnius Lithuania-also marketed as Emperor in some European countries; Aachen Resonance, Germany, and AB Medica, Italy) for the treatment of patients with femoropopliteal lesions.

METHODS

From January 2019 to January 2020, DCB angioplasties using Elutax were performed on 53 consecutive patients (53 limbs) with femoropopliteal lesions (group A) and compared with a noncontemporary control group (group B) consisting of 71 patients (71 limbs) treated with plain old balloon angioplasty (POBA) between January 2017 and January 2018. Before performing the angioplasty, both groups underwent clinical examination, ultrasound evaluation, and computed tomography angiography to delineate subject clinical and baseline lesion characteristics. Primary end point was primary patency rate at 24 months. Secondary end points included clinically driven target lesion revascularization (CD-TLR), overall survival and limb salvage rates.

RESULTS

In both groups technical success rate was 100% with bailout stenting performed in 16.9% (9/53) of lesions in group A, while stenting was necessary in 22.5% of lesions (16/71) in group B. Patients treated with Elutax exhibited lower 24-month restenosis/reocclusion rate and improved primary patency compared to those treated with POBA (restenosis/reocclusion rate: 9.4% vs. 25.3%, CI 95% 0.01-0.30, P = 0.034; primary patency: 88.2% vs. 71.5%, log rank P = 0.03). Twenty-four-month CD-TLR rate was 7.5% for DCB versus 18.3% for POBA. No device or procedure-related deaths occurred, and no 30-day mortality was observed in either group. During the follow-up period, the limb salvage rate was 94.9% for A group and 92.1% for B group. All minor amputations occurred in limbs presented with chronic limb threatening ischemia (CLTI). Overall survival was 91.7% for group A and 89.4% for group B.

CONCLUSIONS

Paclitaxel + Dextran DCB angioplasty proved safe and effective in managing chronic lesions of femoropopliteal arteries. Our experience has shown superior primary patency rate for Elutax when compared to POBA.

Cardiovascular and Limb Events Following Endovascular Revascularization Among Patients ≥65 Years Old: An American College of Cardiology PVI Registry Analysis

Background We aimed to characterize the occurrence of major adverse cardiovascular and limb events (MACE and MALE) among patients with peripheral artery disease (PAD) undergoing peripheral vascular intervention (PVI), as well as associated factors in patients with chronic limb threatening ischemia (CLTI). Methods and Results Patients undergoing PVI in the American College of Cardiology's (ACC) National Cardiovascular Data Registry's PVI Registry who could be linked to Centers for Medicare and Medicaid Services data were included. The primary outcomes were MACE, MALE, and readmission within 1 month and 1 year following index CLTI-PVI or non-CLTI-PVI. Cox proportional hazards regression was used to identify factors associated with the development of the primary outcomes among patients undergoing CLTI-PVI. There were 1758 (49.7%) patients undergoing CLTI-PVI and 1779 (50.3%) undergoing non-CLTI-PVI. By 1 year, MACE occurred in 29.5% of patients with CLTI (n=519), and MALE occurred in 34.0% of patients with CLTI (n=598). By 1 year, MACE occurred in 8.2% of patients with non-CLTI (n=146), and MALE occurred in 26.1% of patients with non-CLTI (n=465). Predictors of MACE at 1 year in CLTI-PVI included end-stage renal disease on hemodialysis, congestive heart failure, prior CABG, and severe lung disease. Predictors of MALE at 1 year in CLTI-PVI included treatment of a prior bypass graft, profunda femoral artery treatment, end-stage renal disease on hemodialysis, and treatment of a previously treated lesion. Conclusions Patients ≥65 years old undergoing PVI experience high rates of MACE and MALE. A range of modifiable and non-modifiable patient factors, procedural characteristics, and medications are associated with the occurrence of MACE and MALE following CLTI-PVI.

Clinical Implications of Phenotypes of Hemodialysis Patients With Central Venous Occlusion or Central Venous Stenosis Defined by Cluster Analysis

Objective

This study aims to investigate the association between clinical factors of patients with central (superior vena cava, brachiocephalic, or subclavian) venous occlusion or central venous stenosis (CVO/CVS) and the difficulty of interventional recanalization as well as the duration of postoperative patency.

Methods

A total of 103 hemodialysis patients with CVO/CVS treated with endovascular treatment were enrolled. The two-step cluster analysis was selected to differentiate the cases into distinct phenotypes automatically. Differences in characteristics, the difficulty of interventional recanalization, and the duration of postoperative primary patency time between the two clusters were statistically compared.

Results

The 103 cases were divided into distinct two clusters by the two-step cluster analysis with 48 (46.6%) in cluster 1 and 55 (53.4%) in cluster 2. Compared to cluster 2, patients in cluster 1 have a higher proportion of blunt stump, side branches, occlusion lesions >2 cm, calcification, or organization. Moreover, the above four factors were, in turn, the most critical four predictors distinguishing 103 patients into two clusters. The remaining six factors were, in turn, occlusion located in the superior vena cava (SVC), duration of central venous catheterization (CVC), lesion location, vessel diameter, number of CVC, and previously failed lesion. Of the four most important factors, with the exception of occlusion lesions exceeding 2 cm, there were significant differences in the length of procedure time between the groups grouped by the remaining three factors. And there was a significant difference in the primary patency rate between the group with blunt stump and the group without blunt stump and also between the group with occlusion lesions ≥ 2 cm and the group with occlusion lesions <2 cm. The operation time of cluster 1 was longer than that of cluster 2. In terms of postoperative patency time, the primary patency time was significantly longer in the patients of cluster 2 compared with cluster 1 (P = 0.025).

Conclusion

Patients were divided into distinct two clusters. CVO/CVS of patients in cluster 1 was more challenging to be recanalized than that in cluster 2, and the primary patency time was significantly longer in the patients of cluster 2 compared with cluster 1. Blunt stump, side branches, occlusion lesions exceeding 2 cm, and calcification or organization are the four most critical predictors distinguishing 103 patients into two clusters.

Prediction of 2-Year Major Adverse Limb Event-Free Survival After Percutaneous Transluminal Angioplasty and Stenting for Lower Limb Atherosclerosis Obliterans: A Machine Learning-Based Study

Background

The current scoring systems could not predict prognosis after endovascular therapy for peripheral artery disease. Machine learning could make predictions for future events by learning a specific pattern from existing data. This study aimed to demonstrate machine learning could make an accurate prediction for 2-year major adverse limb event-free survival (MFS) after percutaneous transluminal angioplasty (PTA) and stenting for lower limb atherosclerosis obliterans (ASO).

Methods

A lower limb ASO cohort of 392 patients who received PTA and stenting was split to the training set and test set by 4:1 in chronological order. Demographic, medical, and imaging data were used to build machine learning models to predict 2-year MFS. The discrimination and calibration of artificial neural network (ANN) and random forest models were compared with the logistic regression model, using the area under the receiver operating curve (ROCAUC) with DeLong test, and the calibration curve with Hosmer–Lemeshow goodness-of-fit test, respectively.

Results

The ANN model (ROCAUC = 0.80, 95% CI: 0.68–0.89) but not the random forest model (ROCAUC = 0.78, 95% CI: 0.66–0.87) significantly outperformed the logistic regression model (ROCAUC = 0.73, 95% CI: 0.60–0.83, P = 0.01 and P = 0.24). The ANN model the logistic regression model demonstrated good calibration performance (P = 0.73 and P = 0.28), while the random forest model showed poor calibration (P < 0.01). The calibration curve of the ANN model was visually the closest to the perfectly calibrated line.

Conclusion

Machine learning models could accurately predict 2-year MFS after PTA and stenting for lower limb ASO, in which the ANN model had better discrimination and calibration. Machine learning-derived prediction tools might be clinically useful to automatically identify candidates for PTA and stenting.

Orbital Atherectomy Prior to Drug-Coated Balloon Angioplasty in Calcified Infrapopliteal Lesions: A Randomized, Multicenter Pilot Study

PURPOSE

Optimal balloon angioplasty for infrapopliteal lesions is often limited by severe calcification, which has been associated with decreased procedural success and lower long-term patency.

MATERIALS AND METHODS

This was a prospective, randomized, multicenter pilot trial that included adult subjects with calcified lesions located from the popliteal segment below the knee (BTK) joint to within 5 cm above the ankle with ≥70% diameter stenosis by angiography. Patients were randomized 1:1 to undergo orbital atherectomy (OA) with adjunctive drug-coated balloon (DCB) angioplasty versus plain balloon angioplasty (BA) and DCB angioplasty (control). The periprocedural and 12 month outcomes of both procedures were compared.

RESULTS

Overall, 66 subjects (OA + DCB = 32 vs control = 34) were included in an intention to treat analysis. Baseline demographics and lesion characteristics were well-balanced. The mean lesion length was 101.3 mm (SD = 72.8 mm) and 78.8 (SD = 61.0 mm) in the OA + DCB and control groups, respectively, with almost all lesions having severe calcification per the Peripheral Academic Research Consortium (PARC) criteria. Chronic total occlusions (CTOs) were present in 43.8% and 35.3% of the patients in the OA + DCB and control groups, respectively. The technical success of OA + DCB versus DCB was 81.8% and 89.2%, respectively, with 3 slow flow/no reflow, 1 perforation, 1 severe dissection occurred in OA + DCB group, and one distal embolization occurred in the control group. The target lesion primary patency rate was numerically higher in the OA + DCB versus control group at 6 (88.2% vs 50.0%, p=0.065) and 12 month follow-up (88.2% vs 54.5%, p=0.076). The 12 month freedom from major adverse events, clinically-driven target lesion revascularization, major amputation, and all-cause mortality rates were similar between both groups.

CONCLUSION

The results of the Orbital Vessel PreparaTIon to MaximIZe Dcb Efficacy in Calcified BTK (OPTIMIZE BTK) pilot study indicated that utilization of OA + DCB is safe for infrapopliteal disease. Further prospective adequately powered studies should investigate the potential benefit of combined OA + DCB for BTK lesions.

The catastrophic impact of COVID-19 infection in patients with chronic limb-threatening ischemia

Background

To determine the impact of COVID-19 infection in patients with chronic limb-threatening ischemia, mainly the limb salvage estimates rate and the overall survival.

Methods

This was a retrospective, consecutive cohort study of chronic limb-threatening ischemia in patients with COVID-19 infection.

Results

Overall, 35 patients with chronic limb-threatening ischemia and COVID-19 infection were evaluated. The mean age of the patients was 72.51 years, and most of them were male (60%), with arterial hypertension (85.7%), followed by diabetes mellitus (80%) and tobacco user (71.4%). There was a higher prevalence of wound, ischemia and foot infection (WIfI) classification 4 with 58.8% and Rutherford grade 5 (74.3%). The factors related to overall mortality rate were: D-dimer >1,000 mg/dL (hazard ratio = 22.7, P < .001, confidence interval = 10.49–26.52), respiratory symptoms (hazard ratio = 16.6, P < .001, confidence interval = 9.87–20.90), chest computed tomography compromising higher than 50% of the pulmonary tract (hazard ratio = 16,0, P < .001, confidence interval = 10.41–20.55), acute kidney failure (hazard ratio = 21.58, P < .001, confidence interval = 16.5–30.5), chronic kidney disease (hazard ratio = 4.4, P = .036, confidence interval = 1.45–10.1), therapeutic anticoagulation (hazard ratio = 8.37, P = .004, confidence interval = 1.35–8.45), and WIfI classification (hazard ratio = 5.28, P = .022, confidence interval = 1.34–10.01). The following were related to limb loss: D-dimer >1,000 mg/mL (hazard ratio = 5.47, P = .02, confidence interval = 1.94–10.52), respiratory symptoms (hazard ratio = 5.42, P = .02, confidence interval = 1.87–10.90), and WIfI classification (hazard ratio = 4.44, P = .035, confidence interval = 1.34–8.01).

Conclusion

This study concluded that COVID-19 has a catastrophic impact among patients with chronic limb-threatening ischemia. The main factors related to overall mortality were D-dimer >1,000 mg/dL, respiratory symptoms, chest computed tomography compromising higher than 50% of the pulmonary tract, acute kidney failure, chronic kidney disease, therapeutic anticoagulation, and WIfI classification. The factors related to limb loss were WIfI classification, D-dimer >1,000 mg/mL and respiratory symptoms.

Association of Postangioplasty Femoropopliteal Dissections With Outcomes After Drug-Coated Balloon Angioplasty in the Femoropopliteal Arteries

PURPOSE

Balloon angioplasty for the treatment of femoropopliteal lesions is often complicated by postangioplasty dissections. While dissections are known to affect patency and reintervention after balloon angioplasty, the association between dissections and major adverse limb event (MALE) after drug-coated balloon (DCB) angioplasty remains uncertain. Thus, the postangioplasty dissection and bailout stenting patterns were investigated.

MATERIALS AND METHODS

This was a single-center retrospective study enrolling patients with de novo femoropopliteal lesions treated with DCB with/without stenting. Postangioplasty target vessel dissection was graded based to the coronary artery classification grades A-F, with grade C-F considered "severe." Cox regression analysis was performed to examine the association of dissection severity with outcomes during 2-year follow up, among nonstented cases.

RESULTS

In 85.3% of the cases (N=203/238) a postangioplasty dissection was observed. The average dissection length was 55.57 mm (SD 36.71 mm), with 1 dissection present in 91.8% (N=180/196) and 2 or more dissections present in 8.2% (N=16/196). Dissection severity was grade A (19.8%), B (20.6%), C (23.1%), D (10.9%), E (10.1%), and F (0.8%). Bailout stenting was required in 40.4% of the patients, being more prevalent among grade C and grade E cases. Among 142 nonstented cases, dissections were present in 85.2%. A total of 75 (52.8%) of these dissections were grade A and B, while 46 (32.4%) were grade C to F. Among nonstented cases, grade C (hazard ratio [HR] 5.83; 95% CI 1.25 to 27.31; p=0.025) and grade D (HR 6.32; 95% CI 1.39 to 28.86; p=0.017) vs grade A dissections were associated with a higher risk for 2-year MALE. Multivariate analysis adjusting for several lesion characteristics demonstrated a statistically significant higher risk for 2-year MALE among the severe dissection group (HR 2.94; 95% CI 1.27 to 6.79; p = 0.012). Interestingly, the risks of limb loss (HR 1.30; 95% CI 0.22 to 7.79; p=0.774) and repeat revascularization (HR 0.95; 95% CI 0.40 to 2.26; p=0.905) during follow-up were similar between the 2 groups.

CONCLUSION

This study indicated that nonstented moderate and severe postangioplasty dissections after DCB angioplasty were associated with higher risk for MALE. Future studies are needed to validate our results and determine other dissection characteristics (eg, total dissection length, lumen area, total number of dissections) that may affect the efficacy of DCB.

Successful Peripheral Vascular Intervention in Patients with High-risk Comorbidities or Lesion Characteristics

PURPOSE OF REVIEW

Certain comorbidities and lesion characteristics are associated with increased risk for procedural complications, limb events, and cardiovascular events following peripheral vascular intervention (PVI) in patients with peripheral arterial disease (PAD). The purpose of this review is to provide an overview of high-risk modifiable and unmodifiable patient characteristics and its relative impact on clinical outcomes such as amputation risk and mortality. Furthermore, general approaches to potentially mitigating these risks through pre-intervention planning and use of modern devices and techniques are discussed.

RECENT FINDINGS

Diabetes, tobacco use, and older age remain strong risk factors for the development of peripheral arterial disease. Recent data highlight the significant risk of polyvascular disease on major limb and cardiac events in advanced PAD, and ongoing studies are assessing this risk specifically after PVI. Challenging lesion characteristics such as calcified disease and chronic total occlusions can be successfully treated with PVI by utilizing novel devices (e.g., intravascular lithotripsy, re-entry devices) and techniques (e.g., subintimal arterial "flossing" with antegrade-retrograde intervention). Understanding high-risk patient comorbidities and lesion characteristics will improve our ability to counsel and manage patients with advanced PAD. Continued device innovation and novel techniques will aid in procedural planning for successful interventions to improve clinical outcomes.

The Effect of Severe Femoropopliteal Arterial Calcification on the Treatment Outcome of Femoropopliteal Intervention in Patients with Ischemic Tissue Loss

Purpose

We investigated the effect of severe calcification of the femoropopliteal artery on intervention outcomes in patients with ischemic tissue loss.

Materials and Methods

A retrospective review of the first endovascular treatment of the femoropopliteal artery for ischemic tissue loss between May 2010 and February 2018 was performed. The calcification of femoropopliteal lesions was estimated by the Compliance 360° score, and lesions with a score of 4 were defined as severe calcification lesions.

Results

Overall, 135 first femoropopliteal endovascular procedures on 135 limbs from 112 patients were included in this study. Among the 135 limbs that received treatement of the femoropopliteal arteries, 74 limbs had Trans-Atlantic Inter Society Consensus (TASC) A or B lesions and 61 limbs had TASC C or D lesions. Among 61 cases of TASC C or D lesions, 21 limbs (34.4%) had severe calcification; there was no statistically significant difference in limb salvage (P=0.75), and amputation-free survival (P=0.11) based on the degree of calcification. However, the survival rate in TASC C or D lesions was significantly different between the two groups (non-severe calcification group vs severe calcification group at 1-year, 2-years, and 3-years: 88.6%, 79.7%, and 61.0% vs 70.0%, 56.0%, and 28.0%, respectively, P=0.01). In multivariate analysis of influencing factors for poor survival in TASC C or D using the Cox proportional hazards model, severe calcification (hazard ratio, 2.362; 95% confidence interval, 1.035-5.391; P=0.041) was a statistically significant risk factor.

Conclusion

Severe femoropopliteal artery calcification was associated with poor survival, especially in TASC C or D lesions.

Balloon Angioplasty of Infrapopliteal Arteries: A Systematic Review and Proposed Algorithm for Optimal Endovascular Therapy

Endovascular revascularization has been increasingly utilized to treat patients with chronic limb-threatening ischemia (CLTI), particularly atherosclerotic disease in the infrapopliteal arteries. Lesions of the infrapopliteal arteries are the result of 2 different etiologies: medial calcification and intimal atheromatous plaque. Although several devices are available for endovascular treatment of infrapopliteal lesions, balloon angioplasty still comprises the mainstay of therapy due to a lack of purpose-built devices. The mechanism of balloon angioplasty consists of adventitial stretching, medial necrosis, and dissection or plaque fracture. In many cases, the diffuse nature of infrapopliteal disease and plaque complexity may lead to dissection, recoil, and early restenosis. Optimal balloon angioplasty requires careful attention to assessment of vessel calcification, appropriate vessel sizing, and the use of long balloons with prolonged inflation times, as outlined in a treatment algorithm based on this systematic review. Further development of specific devices for this arterial segment are warranted, including devices for preventing recoil (eg, dedicated atherectomy devices), treating dissections (eg, tacks, stents), and preventing neointimal hyperplasia (eg, novel drug delivery techniques and drug-eluting stents). Further understanding of infrapopliteal disease, along with the development of new technologies, will help optimize the durability of endovascular interventions and ultimately improve the limb-related outcomes of patients with CLTI.