Major Adverse Limb Events Research Articles

Supra-Inguinal Inflow for Distal Bypasses Have Acceptable Patency and Limb Salvage Rates

There is a paucity of data evaluating outcomes of lower extremity bypass (LEB) using supra-inguinal inflow for revascularization of infra-inguinal vessels. The purpose of this study is to report outcomes after LEB originating from aortoiliac arteries to infra-femoral targets. The Vascular Quality Initiative database (2003-2020) was queried for patients undergoing LEB from the aortoiliac arteries to the popliteal and tibial arteries. Patients were stratified into 3 cohorts based on outflow targets (above-knee [AK] popliteal, below-knee [BK] popliteal, and tibial arteries). Perioperative and 1-year outcomes including primary patency, amputation-free survival (AFS), and major adverse limb events (MALEs) were compared. A Cox proportional hazards model was used to estimate the independent prognostic factors of outcomes. Of 403 LEBs, 389 (96.5%) originated from the external iliac artery, while the remaining used the aorta or common iliac artery as inflow. In terms of the distal target, the AK popliteal was used in 116 (28.8%), the BK popliteal in 151 (27.5%), and tibial vessels in 136 (43.7%) cases. BK popliteal and tibial bypasses, compared to AK popliteal bypasses, were more commonly performed in patients with chronic limb-threatening ischemia (69.5% and 69.9% vs. 48.3%; P<0.001). Vein conduit was more often used for tibial bypass than for AK and BK popliteal bypasses (46.3% vs. 21.9% and 16.3%; P<0.001). In the perioperative period, BK popliteal and tibial bypass patients had higher reoperation rates (16.9% and 13.2% vs. 5.2%; P=0.02) and lower primary patency (89.4% and 89% vs. 95.7%; P=0.04) than AK bypass patients. At 1year, compared with AK popliteal bypasses, BK and tibial bypasses demonstrated lower primary patency (81.9% vs. 56.7% vs. 52.4%, P<0.001) and freedom from MALE (77.6% vs. 70.2% vs. 63.1%, P=0.04), although AFS was not significantly different (89.7% vs. 90.6% vs. 83.8%, P=0.19).On multivariable analysis, compared with AK popliteal bypasses, tibial bypasses were independently associated with increased loss of primary patency (hazard ratio 1.9, 95% confidence interval, 1.03-3.51, P=0.04). Subanalysis of patients with chronic limb-threatening ischemia demonstrated significantly higher primary patency in the AK popliteal cohort at discharge and 1 year, but no difference in AFS or freedom from MALE between the cohorts at follow-up. LEB with supra-inguinal inflow appear to have acceptable rates of 1-year patency and limb salvage in patients at high risk of bypass failure. Tibial outflow target was independently associated with worse primary patency but not with MALE or AFS.

Associations between lipoprotein(a), oxidized phospholipids, and extracoronary vascular disease

The roles of lipoprotein(a) [Lp(a)] and related oxidized phospholipids (OxPLs) in the development and progression of coronary disease is known, but their influence on extracoronary vascular disease is not well-established. We sought to evaluate associations between Lp(a), OxPL apolipoprotein B (OxPL-apoB), and apolipoprotein(a) (OxPL-apo(a)) with angiographic extracoronary vascular disease and incident major adverse limb events (MALEs). Four hundred forty-six participants who underwent coronary and/or peripheral angiography were followed up for a median of 3.7 years. Lp(a) and OxPLs were measured before angiography. Elevated Lp(a) was defined as ≥150 nmol/L. Elevated OxPL-apoB and OxPL-apo(a) were defined as greater than or equal to the 75th percentile (OxPL-apoB ≥8.2 nmol/L and OxPL-apo(a) ≥35.8 nmol/L, respectively). Elevated Lp(a) had a stronger association with the presence of extracoronary vascular disease compared to OxPLs and was minimally improved with the addition of OxPLs in multivariable models. Compared to participants with normal Lp(a) and OxPL concentrations, participants with elevated Lp(a) levels were twice as likely to experience a MALE (odds ratio: 2.14, 95% confidence interval: 1.03, 4.44), and the strength of the association as well as the C statistic of 0.82 was largely unchanged with the addition of OxPL-apoB and OxPL-apo(a). Elevated Lp(a) and OxPLs are risk factors for progression and complications of extracoronary vascular disease. However, the addition of OxPLs to Lp(a) does not provide additional information about risk of extracoronary vascular disease. Therefore, Lp(a) alone captures the risk profile of Lp(a), OxPL-apoB, and OxPL-apo(a) in the development and progression of atherosclerotic plaque in peripheral arteries.

Assessing the Suitability of CHA2DS2-VASc for Predicting Adverse Limb Events and Cardiovascular Outcomes in Peripheral Artery Disease Patients with Percutaneous Transluminal Angioplasty: A Retrospective Cohort Study.

Patients with peripheral artery disease (PAD) are at high risk of major adverse limb events (MALEs) and major adverse cardiovascular events (MACEs). CHA2DS2-VASc is a prognostic score for atrial fibrillation stroke risk; however, no study has evaluated its predictive ability for MALEs and MACEs in PAD patients who underwent percutaneous transluminal angioplasty. We conducted a retrospective cohort study on patients from Taiwan with PAD. The patients were stratified into four risk groups based on their modified CHA2DS2-VASc score. Cox proportional hazard models, 10-fold cross-validation, and receiver operating characteristic (ROC) analyses were utilized to evaluate the predictive ability of CHA2DS2-VASc for MALEs, MACEs, and MALEs + MACEs. Kaplan-Meier analysis estimated the survival probability of the risk groups. CHA2DS2-VASc was found to be a significant predictor of MACEs (hazard ratio (HR) 3.52 (95% confidence interval (95% CI) 1.00-12.12; p = 0.048), HR 4.18 (95% CI 1.19-14.36; p = 0.023), and HR 5.08 (95% CI 1.49-17.36; p = 0.009), for moderate-, high-, and very high-risk groups, respectively), while for MALEs and MALEs + MACEs, significance was achieved only for the high-risk group using a univariate model. For the multivariate adjusted model, the score was found to be a significant predictor of MACEs for only the very high-risk group, with an HR of 4.67 (95% CI 1.03-21.09; p = 0.045). The score demonstrated an AUC > 0.8, good discrimination (c-index > 0.8), and good calibration for predicting MACEs. However, it failed to achieve good performance for predicting MALEs and MALEs + MACEs. Based on all of the findings, CHA2DS2-VASc could potentially serve as a risk stratification score for predicting MACEs in patients with PAD, but it failed to qualify as a good predictor for MALEs.

The Identification and Evaluation of Interleukin-7 as a Myokine Biomarker for Peripheral Artery Disease Prognosis.

Background/Objectives: Myokines have been demonstrated to be associated with cardiovascular diseases; however, they have not been studied as biomarkers for peripheral artery disease (PAD). We identified interleukin-7 (IL-7) as a prognostic biomarker for PAD from a panel of myokines and developed predictive models for 2-year major adverse limb events (MALEs) using clinical features and plasma IL-7 levels. Methods: A prognostic study was conducted with a cohort of 476 patients (312 with PAD and 164 without PAD) that were recruited prospectively. Their plasma concentrations of five circulating myokines were measured at recruitment, and the patients were followed for two years. The outcome of interest was two-year MALEs (composite of major amputation, vascular intervention, or acute limb ischemia). Cox proportional hazards analysis was performed to identify IL-7 as the only myokine that was associated with 2-year MALEs. The data were randomly divided into training (70%) and test sets (30%). A random forest model was trained using clinical characteristics (demographics, comorbidities, and medications) and plasma IL-7 levels with 10-fold cross-validation. The primary model evaluation metric was the F1 score. The prognostic model was used to classify patients into low vs. high risk of developing adverse limb events based on the Youden Index. Freedom from MALEs over 2 years was compared between the risk-stratified groups using Cox proportional hazards analysis. Results: Two-year MALEs occurred in 28 (9%) of patients with PAD. IL-7 was the only myokine that was statistically significantly correlated with two-year MALE (HR 1.56 [95% CI 1.12-1.88], p = 0.007). For the prognosis of 2-year MALEs, our model achieved an F1 score of 0.829 using plasma IL-7 levels in combination with clinical features. Patients classified as high-risk by the predictive model were significantly more likely to develop MALEs over a 2-year period (HR 1.66 [95% CI 1.22-1.98], p = 0.006). Conclusions: From a panel of myokines, IL-7 was identified as a prognostic biomarker for PAD. Using a combination of clinical characteristics and plasma IL-7 levels, we propose an accurate predictive model for 2-year MALEs in patients with PAD. Our model may support PAD risk stratification, guiding clinical decisions on additional vascular evaluation, specialist referrals, and medical/surgical management, thereby improving outcomes.

Learning curve in tibial and pedal bypass with autologous vein graft.

The 2019 Global Vascular Guidelines recommended open bypass for patients at average risk with greater limb severity and anatomical complexity. However, the outcomes of tibial and pedal bypass (TPB) are inferior to those of above-the-knee surgical revascularization. This may be due to the technical difficulty and need for development of skills to perform TPB. However, there is a limited knowledge on the learning curve in TPB. Thus, the aim of the study is to assess this learning curve in a single-center retrospective analysis. Cases treated with TPB with an autologous vein conduit in patients with chronic limb-threatening ischemia (CLTI) at a Japanese single center from 2009 to 2022 were analyzed retrospectively. The primary endpoint was the learning curve for TPB. The study included 449 TPB procedures conducted by a single main surgeon in patients with CLTI (median age, 75 years; 309 males; diabetes mellitus, 73%; end stage renal failure with hemodialysis, 44%). The operative time decreased significantly as the number of cases accumulated (p < .001). Using the cumulative sum (CUSUM) operative time, the learning curve was estimated to be phase 1 (initial learning curve) for 134 cases (1-134); phase 2 (competent period) for 179 cases (135-313); and phase 3 (mastery and challenging period) for 136 cases (314-449). The mean follow-up period was 34 ± 31months. The 1- and 3-year limb salvage rates of 97% and 96% in phase 3 were significantly higher than those in phases 1 and 2 (p < .001, p = .029). Major adverse limb events (MALE) occurred in 117 (26%) patients, and the 1- and 3-year MALE rates of 10% and 17% in phase 3 were significantly lower than those in phases 1 and 2 (p < .001, p = .009). In the study, vascular surgeon required a learning curve of 134 TPB cases to Overcoming the learning curve for bypass was associated with improvement of medium-term outcomes for limb salvage and freedom from MALE.

How multidisciplinary clinics may mitigate socioeconomic barriers to care for chronic limb-threatening ischemia

ObjectiveAlthough multidisciplinary clinics improve outcomes in chronic limb-threatening ischemia (CLTI), their role in addressing socioeconomic disparities is unknown. Our institution treats patients with CLTI at both traditional general vascular clinics and a multidisciplinary Limb Preservation Program (LPP). The LPP is in a minority community, providing expedited care at a single facility by a consistent team. We compared outcomes within the LPP with our institution’s traditional clinics and explored patients’ perspectives on barriers to care to evaluate if the LPP might address them. MethodsAll patients undergoing index revascularization for CLTI from 2014 to 2023 at our institution were stratified by clinic type (LPP or traditional). We collected clinical and socioeconomic variables, including Area Deprivation Index (ADI). Patient characteristics were compared using χ2, Student t, or Mood median tests. Outcomes were compared using log-rank and multivariable Cox analysis. We also conducted semi-structured interviews to understand patient-perceived barriers. ResultsFrom 2014 to 2023, 983 limbs from 871 patients were revascularized; 19.5% of limbs were treated within the LPP. Compared with traditional clinic patients, more LPP patients were non-White (43.75% vs 27.43%; P < .0001), diabetic (82.29% vs 61.19%; P < .0001), dialysis-dependent (29.17% vs 13.40%; P < .0001), had ADI in the most deprived decile (29.38% vs 19.54%; P = .0061), resided closer to clinic (median 6.73 vs 28.84 miles; P = .0120), and had worse Wound, Ischemia, and foot Infection (WIfI) stage (P < .001). There were no differences in freedom from death, major adverse limb event (MALE), or patency loss. Within the most deprived subgroup (ADI >90), traditional clinic patients had earlier patency loss (P = .0108) compared with LPP patients. Multivariable analysis of the entire cohort demonstrated that increasing age, heart failure, dialysis, chronic obstructive pulmonary disease, and increasing WIfI stage were independently associated with earlier death, and male sex was associated with earlier MALE. Ten traditional clinic patients were interviewed via convenience sampling. Emerging themes included difficulty understanding their disease, high visit frequency, transportation barriers, distrust of the health care system, and patient-physician racial discordance. ConclusionsLPP patients had worse comorbidities and socioeconomic deprivation yet had similar outcomes to healthier, less deprived non-LPP patients. The multidisciplinary clinic’s structure addresses several patient-perceived barriers. Its proximity to disadvantaged patients and ability to conduct multiple appointments at a single visit may address transportation and visit frequency barriers, and the consistent team may facilitate patient education and improve trust. Including these elements in a multidisciplinary clinic and locating it in an area of need may mitigate some negative impacts of socioeconomic deprivation on CLTI outcomes.

Anatomical and clinical factors associated with infrapopliteal arterial bypass outcomes in patients with chronic limb-threatening ischemia

The aim of this study was to identify anatomical and clinical factors associated with limb-based patency (LBP) loss, major adverse limb events (MALEs), and poor amputation-free survival (AFS) after an infrapopliteal arterial bypass (IAB) surgery according to the Global Limb Anatomic Staging System. A retrospective analysis of patients undergoing IAB surgery between January 2010 and December 2021 at a single institution was performed. Two-year AFS, freedom from LBP loss, and freedom from MALEs were assessed using the Kaplan–Meier method. Anatomical and clinical predictors were assessed using multivariate analysis. The total number of risk factors was used to calculate risk scores for subsequent categorization into low-, moderate-, and high-risk groups. IABs were performed on 103 patients. The rates of two-year freedom from LBP loss, freedom from MALEs, and AFS were 71.3%, 76.1%, and 77.0%, respectively. The multivariate analysis showed that poor run-off beyond the ankle and a bypass vein caliber of < 3 mm were significantly associated with LBP loss and MALEs. Moreover, end-stage renal disease, non-ambulatory status, and a body mass index of < 18.5 were significantly associated with poor AFS. The rates of freedom from LBP loss and MALEs and the AFS rate were significantly lower in the high-risk group than in the other two groups (12-month low-risk rates: 92.2%, 94.8%, and 94.4%, respectively; 12-month moderate-risk rates: 58.6%, 84.6%, and 78.3%, respectively; 12-month high-risk rates: 11.1%, 17.6%, and 56.2%, respectively; p < 0.001, p < 0.001, and p < 0.001, respectively). IAB is associated with poor clinical outcomes in terms of LBP, MALEs, and AFS in high-risk patients. Risk stratification based on these predictors is useful for long-term prognosis.

Outcomes of Revascularisation for Treating Lifestyle-Limiting Intermittent Claudication in Aboriginal and Torres Strait Islander People and Non-Indigenous Patients from North Queensland: A Retrospective Cohort Study.

Background: This retrospective analysis of an ongoing prospective cohort study aimed to assess the outcome of revascularisation for treating lifestyle-limiting intermittent claudication caused by peripheral artery disease (PAD) in Aboriginal and Torres Strait Islander Peoples and non-Indigenous North Queenslanders. Methods: Consenting patients with PAD who underwent endovascular or open revascularisation procedures for treating lifestyle-limiting intermittent claudication were included. The primary outcome measure was major adverse limb events (MALEs), defined as major amputation or the requirement for repeat open or endovascular revascularisation. Results: Of the 378 included patients, 18 (4.8%) identified as Aboriginal and/or Torres Strait Islander Peoples. During a mean follow-up (standard deviation) of 6.0 (3.9) years, the incidence of MALE was similar in the Aboriginal and Torres Strait Islander People and non-Indigenous Australians (absolute percentage: 50.0% vs. 40.6%, log rank p = 0.59). In both unadjusted and adjusted analyses, Aboriginal and Torres Strait Islander Peoples and non-Indigenous Australians had similar risks of MALE (unadjusted hazard ratio, HR, 1.20, 95% confidence interval, CI, 0.61, 2.36; adjusted HR 1.02, 95%CI 0.50, 2.06). Conclusions: This study suggests that Aboriginal and Torres Strait Islander People are under-represented in the population of patients undergoing revascularisation to treat intermittent claudication. Due to small numbers it cannot be reliably concluded that Aboriginal and Torres Strait Islander People and non-Indigenous Australians have similar rates of MALE.

Surgery or endovascular therapy for patients with chronic limb-threatening ischemia requiring infrapopliteal interventions

ObjectiveThe recent publication of randomized trials comparing open bypass surgery to endovascular therapy in patients with chronic limb-threatening ischemia, namely, Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) and Bypass versus Angioplasty in Severe Ischaemia of the Leg-2 (BASIL-2), has resulted in potentially contradictory findings. The trials differed significantly with respect to anatomical disease patterns and primary end points. We performed an analysis of patients in BEST-CLI with significant infrapopliteal disease undergoing open tibial bypass or endovascular tibial interventions to formulate a relevant comparator with the outcomes reported from BASIL-2. MethodsThe study population consisted of patients in BEST-CLI with adequate single segment saphenous vein conduit randomized to open bypass or endovascular intervention (cohort 1) who additionally had significant infrapopliteal disease and underwent tibial level intervention. The primary outcome was major adverse limb event (MALE) or all-cause death. MALE included any major limb amputation or major reintervention. Outcomes were evaluated using Cox proportional regression models. ResultsThe analyzed subgroup included a total of 665 patients with 326 in the open tibial bypass group and 339 in the tibial endovascular intervention group. The primary outcome of MALE or all-cause death at 3 years was significantly lower in the surgical group at 48.5% compared with 56.7% in the endovascular group (P = .0018). Mortality was similar between groups (35.5% open vs 35.8% endovascular; P = .94), whereas MALE events were lower in the surgical group (23.3% vs 35.0%; P<.0001). This difference included a lower rate of major reinterventions in the surgical group (10.9%) compared with the endovascular group (20.2%; P = .0006). Freedom from above ankle amputation or all-cause death was similar between treatment arms at 43.6% in the surgical group compared with 45.3% the endovascular group (P = .30); however, there were fewer above ankle amputations in the surgical group (13.5%) compared with the endovascular group (19.3%; P = .0205). Perioperative (30-day) death rates were similar between treatment groups (2.5% open vs 2.4% endovascular; P = .93), as was 30-day major adverse cardiovascular events (5.3% open vs 2.7% endovascular; P = .12). ConclusionsAmong patients with suitable single segment great saphenous vein who underwent infrapopliteal revascularization for chronic limb-threatening ischemia, open bypass surgery was associated with a lower incidence of MALE or death and fewer major amputation compared with endovascular intervention. Amputation-free survival was similar between the groups. Further investigations into differences in comorbidities, anatomical extent, and lesion complexity are needed to explain differences between the BEST-CLI and BASIL-2 reported outcomes.

Implementation of a vascular acute care surgery model is associated with improved surgeon efficiency and 2-year mortality after lower extremity intervention

ObjectiveVascular surgeons work long, unpredictable hours with repeated exposure to high-stress situations. Inspired by general surgery acute care surgery models, we sought to organize the care of vascular emergencies with the implementation of a vascular acute care surgery (VACS) model. Within this model, a surgeon is in-house without elective cases and assigned for consultations and urgent operative cases on a weekly basis. This study examined the impact of a VACS model on postoperative mortality and surgeon efficiency. MethodsThis was a retrospective cohort analysis of institutional Vascular Quality Initiative data from July 2014 to July 2023. Patients undergoing lower extremity bypass, peripheral vascular intervention, or amputation were included. There was a washout period from January 2020 to January 2022 to account for COVID-19 pandemic practice abnormalities. Patients were separated into pre- or post-VACS groups. The primary clinical outcomes were 30-day and 2-year mortality. Secondary clinical outcomes included 30-day complications and 30-day and 1-year major adverse limb events (MALE). Separate analyses of operating room data from July 2017 to February 2024 and fiscal data from fiscal year 2019 to fiscal year 2024 were conducted. A washout period from January 2020 to January 2022 was applied. Efficiency outcomes included monthly relative value units (RVUs) per clinical fraction full-time equivalent (cFTE) and daytime (0730-1700, Monday-Friday) operating room minutes. Patient factors and operative efficiency were compared using appropriate statistical tests. Regression modeling was performed for the primary outcomes. ResultsThere were 972 and 257 patients in the pre- and post-VACS groups, respectively. Pre-VACS patients were younger (66.8 ± 12.0 vs 68.7 ± 12.7 years; P = .03) with higher rates of coronary artery disease (34.6% vs 14.8%; P < .01), hypertension (88.4% vs 82.2%; P = .01), and tobacco history (84.4% vs 78.2%; P = .02). Thirty-day mortality (2.4% pre-vs 0.8% post-VACS; P = .18) and Kaplan-Meier estimation of 2-year mortality remained stable after VACS (P = .07). VACS implementation was not associated with 30-day mortality but was associated with lower 2-year mortality hazard on multivariable Cox regression (hazard ratio [HR], 0.5; 95% confidence interval [CI], 0.3-0.9; P = .01). Operative efficiency improved post-VACS (median, 850.0; interquartile range [IQR], 765.7-916.3 vs median, 918.0; IQR, 881.0-951.1 RVU/cFTE-month; P = .03). Daytime operating minutes increased (469.1 ± 287.5 vs 908.2 ± 386.2 minutes; P < .01), whereas non-daytime minutes (420.0; IQR, 266.0-654.0 vs 469.5; IQR, 242.0-738.3 minutes; P = .40) and weekend minutes (129.0; IQR, 0.0-298.0 vs 113.5; IQR, 0.0-279.5 minutes; P = .59) remained stable. ConclusionsA VACS model leads to improvement in surgeon operative efficiency while maintaining patient safety. The adoption of a vascular acute care model has a positive impact on the delivery of comprehensive vascular care.

The Role of Lipoprotein(a) in Peripheral Artery Disease.

Lipoprotein(a) is a low-density-lipoprotein-like particle that consists of apolipoprotein(a) bound to apolipoprotein(b). It has emerged as an established causal risk factor for atherosclerotic cardiovascular disease, stroke, and aortic valve stenosis through multifactorial pathogenic mechanisms that include inflammation, atherogenesis, and thrombosis. Despite an estimated 20% of the global population having elevated lipoprotein(a) levels, testing remains underutilized due to poor awareness and a historical lack of effective and safe therapies. Although lipoprotein(a) has a strong association with coronary artery disease and cerebrovascular disease, its relationship with peripheral artery disease is less well established. In this article, we review the epidemiology, biology, and pathogenesis of lipoprotein(a) as it relates to peripheral artery disease. We also discuss emerging treatment options to help mitigate major adverse cardiac and limb events in this population.

Clinical impact of fluoropolymer-based drug-eluting stent thrombosis in femoropopliteal artery occlusive lesions.

Endovascular treatment (EVT) is recommended for superficial femoral artery (SFA) lesions, and good results have been reported after implantation of drug-eluting stents (DES) for SFA. However, the major concern after implantation is acute thrombosis during the follow-up period, resulting in major amputation and major adverse limb events. In this study, we examined the incidence and outcome of acute thrombosis after DES implantation in the SFA. DES implantation for a femoropopliteal lesion was performed in 288 patients at multiple centers in Japan from 2019 to 2021. A total of 25 patients (8.6%) with DES acute occlusion were analyzed retrospectively. The primary endpoint was amputation-free survival (AFS) after acute occlusion. The median patient age was 77years, with 48% having diabetes, 40% undergoing maintenance dialysis, and 66% having chronic limb-threatening ischemia (CLTI). The mean time from initial DES implantation to acute occlusion was 153.5 ± 177.6days, with a median of 104days. EVT was performed in 18 patients (72%), surgical revascularization in 3 (12%), and conservative treatment in 4 (16%). Two deaths within 30days were both due to sepsis. No major amputation or major adverse cardiovascular events occurred within 30days. The 1-year rates of patency and freedom from target lesion revascularization after DES thrombosis were 22.9% and 48.8%, respectively. AFS at 1 year was 55.1%. Acute DES occlusion is relatively frequent, and the outcome is poor. Therefore, the indication of DES implantation for a complex SFA lesion may require careful consideration. Further investigation may be needed in DES implantation for a complex SFA lesion.

Clinical Implications of Low Body Mass Index on Endovascular Lower Extremity Revascularization

ObjectiveThe epidemic of obesity and associated cardiovascular morbidity continues to grow, attracting public attention and healthcare resources. However, the impact of malnutrition and being underweight continues to be overshadowed by obesity, especially in patients with peripheral arterial disease (PAD). This study assesses the characteristics and outcomes of patients with low body mass index (BMI ≤ 18.5) compared to patients with nonobese BMI undergoing peripheral vascular interventions (PVI). MethodsA retrospective analysis of patients undergoing PVI due to PAD registered in the VQI database. Patients were categorized into underweight (BMI ≤ 18.5) and nonobese BMI (BMI=18.5-30). Patients in both groups were matched 3:1 for baseline demographic characteristics, comorbidities, medications, and indications. Kaplan-Meier analysis was done for long-term outcomes. ResultsA total of 337,926 patients underwent PVI, of whom 12,935 (4%) were underweight, 215,728 (64%) were nonobese, and 109,263 (32%) were obese. Underweight patients were more likely to be older, female, smokers, with COPD, and more likely to present with chronic limb-threatening ischemia than nonobese patients. After propensity matching, there were 18,047 nonobese patients and 6,031 underweight patients. There were no significant differences in matched characteristics.Perioperatively, underweight patients were more likely to require a longer hospital length of stay. Underweight patients had statistically significantly higher 30-day mortality compared to patients with nonobese BMI (3% vs. 1.6%, p<0.001) and a higher rate of thrombotic complications. As for long-term outcomes, underweight patients had a higher rate of reintervention (20% vs. 18%, p<0.001) and major adverse limb events (27% vs. 22%, p<0.001). The 4-year rate of amputation-free survival was significantly lower in underweight patients (70% vs. 82% p<0.001), and the 2-year freedom from major amputation (90% vs. 94% p<0.001) showed similar trends with worse outcomes in patients who were underweight. ConclusionsUnderweight patients with PAD are disproportionally more likely to be African American, females, and smokers and suffer worse outcomes after PVI than PAD patients with nonobese BMI. When possible, increased scrutiny and optimization of nutrition and other factors contributing to low BMI should be addressed prior to PVI.

Midterm Outcomes and Predictors of Failure of Lower Extremity Bypass to Para-Malleolar and Pedal Targets

ObjectivesThe frequency of distal lower extremity bypass (LEB) for infra-popliteal critical limb threatening ischemia (IP-CLTI) has significantly decreased. Our goal was to analyze the contemporary outcomes and factors associated with failure of LEB to para-malleolar and pedal targets. MethodsWe queried the VQI infra-inguinal database from 2003-2021 to identify LEB to para-malleolar or pedal/plantar targets. Primary outcomes were graft patency, major adverse limb events [vascular re-intervention, above ankle amputation] (MALE), and amputation-free survival at 2 years. Standard statistical methods were utilized. ResultsWe identified 2331 LEB procedures (1265 anterior tibial at ankle/dorsalis pedis, 783 posterior tibial at ankle, 283 tarsal/plantar). The prevalence of LEB bypasses to distal targets has significantly decreased from 13.37% of all LEB procedures in 2003 to 3.51% in 2021 (p<0.001). The majority of cases presented with tissue loss (81.25. Common post-operative complications included major adverse cardiac events (8.9%) and surgical site infections (3.6%). Major amputations occurred in 16.8% of patients at 1 year. Post-operative mortality at 1 year was 10%.On unadjusted Kaplan-Meier survival analysis at 2 years, primary patency was 50.56%±3.6%, MALE was 63.49%±3.27%, and amputation-free survival was 71.71%±0.98%. In adjusted analyses [adjusted for comorbidities, indication, conduit type, urgency, prior vascular interventions, graft inflow vessel (femoral/popliteal), concomitant inflow procedures, surgeon and center volume] conduits other than GSV (p<0.001) were associated with loss of primary patency and increased MALE. High center volume (>5 procedures/year) was associated with improved primary patency (p=0.015), and lower MALE (p=0.021) at 2 years. ConclusionsDespite decreased utilization, open surgical bypass to distal targets at the ankle remains a viable option for treatment of IP-CLTI with acceptable patency and amputation-free survival rates at 2 years. Bypasses to distal targets should be performed at high volume centers to optimize graft patency and limb salvage and minimize re-interventions.

The Clinical Impact of Access Site Selection for Successful Thrombolysis and Intervention in Acute Critical Lower Limb Ischaemia (RAD-ALI Registry).

Background: Acute limb ischaemia (ALI) is of great clinical importance due to its consequent serious complications and high comorbidity and mortality rates. The purpose of this study was to compare the acute success and complication rates of CDT performed via transradial, transbrachial, and transfemoral access sites in patients with acute lower limb vascular occlusion and to investigate the 1-year outcomes of CDT and MT for ALI. Methods: Between 2008 and 2019, 84 consecutive patients with ALI were treated with CDT in a large community hospital. Data were collected and retrospectively analysed. The primary ("safety") endpoints encompassed major adverse events (MAEs), major adverse limb events (MALEs), and the occurrence of complications related to the access site. Secondary ("efficacy") endpoints included both technical and clinical achievements, treatment success, fluoroscopy time, radiation dose, procedure time, and the crossover rate to an alternative puncture site. Results: CDT was started with radial (n = 17), brachial (n = 9), or femoral (n = 58) access. CDT was technically successful in 74/84 patients (88%), but additional MT and angioplasty and/or stent implantation was necessary in 17 (20.2%) and 45 cases (53.6%), respectively. Clinical success was achieved in 74/84 cases (88%). The mortality rate at 1 year was 14.3%. The cumulative incidence of MAEs and MALEs at 12 months was 50% and 40.5%, respectively. After conducting multivariate analysis, history of Rutherford stage IIB (hazard ratio [HR], 3.64; 95% confidence interval [CI], 1.58-8.41; p = 0.0025), occlusion of the external iliac artery (HR, 27.52; 95% CI, 2.83-267.33; p = 0.0043), being a case of clinically unsuccessful thrombolysis (HR, 7.72; 95% CI, 2.48-23.10; p = 0.0004), and the presence of diabetes mellitus (HR, 2.18; 95% CI, 1.01-4.71; p = 0.047) were independent predictors of a high MAE mortality rate at 12 months. For MALEs, statistically significant differences were detected with the variables history of Rutherford stage IIB (HR, 4.30; 95% CI, 1.99-9.31; p = 0.0002) and external iliac artery occlusion (HR, 31.27; 95% CI, 3.47-282.23; p = 0.0022). Conclusions: Based on the short-term results of CDT, acute limb ischaemia can be successfully, safely, and effectively treated with catheter-directed thrombolytic therapy with radial, brachial, or femoral access. However, radial access is associated with fewer access site complications. A history of Rutherford stage IIB, occlusion of external iliac artery, unsuccessful thrombolysis, and the presence of diabetes mellitus were independently associated with an increased risk of MAEs. A history of Rutherford stage IIB and external iliac artery occlusion are independent predictors of MALEs.

Comparing Iliac Artery vs Superficial Femoral Artery Stenting in Claudicants With Respect to Long-term Outcomes and Major Adverse Limb Events

Comparing Iliac Artery vs Superficial Femoral Artery Stenting in Claudicants With Respect to Long-term Outcomes and Major Adverse Limb Events

Predictors of bleeding and thrombotic events among patients admitted to the hospital with COVID-19 and elevated D-dimer: insights from the ACTION randomized clinical trial.

Therapeutic anticoagulation showed inconsistent results in hospitalized patients with COVID-19 and selection of the best patients to use this strategy still a challenge balancing the risk of thrombotic and hemorrhagic outcomes. The present post-hoc analysis of the ACTION trial evaluated the variables independently associated with both bleeding events (major bleeding or clinically relevant non-major bleeding) and the composite outcomes thrombotic events (venous thromboembolism, myocardial infarction, stroke, systemic embolism, or major adverse limb events). Variables were assessed one by one with independent logistic regressions and final models were chosen based on Akaike information criteria. The model for bleeding events showed an area under the curve of 0.63 (95% confidence interval [CI] 0.53 to 0.73), while the model for thrombotic events had an area under the curve of 0.72 (95% CI 0.65 to 0.79). Non-invasive respiratory support was associated with thrombotic but not bleeding events, while invasive ventilation was associated with both outcomes (Odds Ratio of 7.03 [95 CI% 1.95 to 25.18] for thrombotic and 3.14 [95% CI 1.11 to 8.84] for bleeding events). Beyond respiratory support, creatinine level (Odds Ratio [OR] 1.01 95% CI 1.00 to 1.02 for every 1.0mg/dL) and history of coronary disease (OR 3.67; 95% CI 1.32 to 10.29) were also independently associated to the risk of thrombotic events. Non-invasive respiratory support, history of coronary disease, and creatinine level may help to identify hospitalized COVID-19 patients at higher risk of thrombotic complications.ClinicalTrials.gov: NCT04394377.

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

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. 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. 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. 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.

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. 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. 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.

Medical Therapy for Peripheral Artery Disease.

Patients with lower extremity peripheral artery disease (PAD) are at high risk for major adverse cardiovascular events (MACE) and major adverse limb events (MALE). This manuscript will review the current evidence for medical therapy in patients with PAD according to different clinical features and the overall cardiovascular (CV) risk. The management of PAD encompasses non-pharmacologic strategies, including lifestyle modification such as smoking cessation, supervised exercise, Mediterranean diet and weight loss as well as pharmacologic interventions, particularly for high risk patients. Benefits for reduction of CV and limb outcomes have been demonstrated for new therapies, including antithrombotic therapy (i.e., low-dose rivaroxaban plus aspirin), lipid lowering therapy (i.e., proprotein convertase subtilisin/kexin type 9inhibitors), and glucose lowering therapy (i.e., sodium-glucose cotransporter-2inhibitors and glucagon-like peptide-1receptor agonists). However, the adoption of these therapies in PAD remains suboptimal in practice. Implementation science studies have recently shown promising results in PAD patients. Comprehensive medical and non-medical management of PAD patients is crucial to improving patient outcomes, mitigating symptoms, and reducing the risk of MACE and MALE. A personalized approach, considering the patient's overall risk profile and preference, is essential for optimizing medical management of PAD.