Treatment Of Peripheral Arterial Disease Research Articles

Gene therapy by virus-like self-spooling toroidal DNA condensates for revascularization of hindlimb ischemia

Peripheral arterial diseases (PAD) have been reported to be the leading cause for limb amputations, and the current therapeutic strategies including antiplatelet medication or intervene surgery are reported to not clinically benefit the patients with high-grade PAD. To this respect, revascularization based on angiogenetic vascular endothelial growth factor (VEGF) gene therapy was attempted for the potential treatment of critical PAD. Aiming for transcellular delivery of VEGF-encoding plasmid DNA (pDNA), we proposed to elaborate intriguing virus-like DNA condensates, wherein the supercoiled rigid micrometer-scaled plasmid DNA (pDNA) could be regulated in an orderly fashion into well-defined nano-toroids by following a self-spooling process with the aid of cationic block copolymer poly(ethylene glycol)-polylysine at an extraordinary ionic strength (NaCl: 600 mM). Moreover, reversible disulfide crosslinking was proposed between the polylysine segments with the aim of stabilizing these intriguing toroidal condensates. Pertaining to the critical hindlimb ischemia, our proposed toroidal VEGF-encoding pDNA condensates demonstrated high levels of VEGF expression at the dosage sites, which consequently contributed to the neo-vasculature (the particularly abundant formation of micro-vessels in the injected hindlimb), preventing the hindlimb ischemia from causing necrosis at the extremities. Moreover, excellent safety profiles have been demonstrated by our proposed toroidal condensates, as opposed to the apparent immunogenicity of the naked pDNA. Hence, our proposed virus-like DNA condensates herald potentials as gene therapy platform in persistent expressions of the therapeutic proteins, and might consequently be highlighted in the management of a variety of intractable diseases.

Applications of SPECT and PET Imaging for the Physiological Evaluation of Lower Extremity Peripheral Artery Disease.

Peripheral artery disease (PAD) is classified as the narrowing or complete occlusion of the lower extremity arteries due to atherosclerosis. The risk of developing PAD increases with increased age and risk factors such as smoking, diabetes, hypertension, and hypercholesterolemia. Current treatment for PAD involves lifestyle and symptom management, statin and antiplatelet therapy, and/or surgical interventions to improve quality of life with varying efficacy. PAD affects approximately 5 to 6 percent of the global population, with this global burden continuing to increase. Despite the increase in disease prevalence, no gold standard functional diagnostic tool has been established for enabling early detection of the disease, appropriate medical management, and prediction of adverse outcomes for PAD patients. The visualization and quantification of the physiological consequences of PAD are possible by way of nuclear imaging: specifically, via scintigraphy, single-photon emission computed tomography (SPECT), and positron emission tomography (PET) imaging. These non-invasive modalities, when combined with targeted radionuclides, possess utility for detecting functional perfusion deficits and provide unique insight into muscle tissue- and vascular-level characteristics of PAD patients. This review discusses the past, present, and emerging applications of hybrid nuclear imaging modalities in the evaluation and monitoring of patients with PAD.

Intravascular Ultrasound during Endovascular Intervention for Peripheral Artery Disease, by Severity, Location, Device, and Procedure

There is limited evidence for the role of Intravascular Ultrasound (IVUS) in patients undergoing peripheral vascular intervention (PVI). We conducted retrospective cohort study utilizing the HCUP-AHRQ National Readmission database(NRD) to delineate outcomes in IVUS guided PVI versus non-IVUS guided PVI. The current study utilized NRD between January 1, 2016, and December 31, 2019. We identified patients undergoing endovascular intervention for peripheral artery disease using relevant ICD-10-PCS. The cohort was divided based on the use of IVUS during the procedure. The primary outcome was major amputation at 6 months after index hospitalization. Measured confounders were matched using propensity score inverse probability of treatment weighing method. We further performed a subgroup analysis based on disease severity, location of intervention, device, and procedure.A total of 434901 hospitalizations were included in the present analysis. PVI with IVUS compared with no IVUS had similar risk of amputation at 6 months (195 of 8939[2.17%] versus 10404 of 384003 [2.71%]);Hazard Ratio,0.98;CI, 0.77–1.25. Further, there was no difference in the rates of secondary outcomes. On subgroup analysis, amputation rates were significantly lower among patients with rest pain, in iliac intervention, or patients undergoing drug eluting stent implantation with the use of IVUS compared with no IVUS. This nationwide observational study showed that there was no difference in major amputation rates with the use of IVUS in patients undergoing PVI. However, in subgroup of patients with rest pain, iliac intervention or drug-eluting stent implantation IVUS use was associated with significantly lower major amputation rates.

Medicine's Glass Slipper: The PAVAEX Boot and 20th Century Negative Pressure Therapy.

Before the 20th century, peripheral artery disease (PAD) manifested as extreme pain, chronic wounds, and, eventually, gangrene requiring amputation. Despite this, it was rarely diagnosed. However, at the turn of the century, Western medicine shifted focus from infectious to chronic illnesses, and with this change, physicians' engagement with PAD transformed. Aiming to mitigate long-term injury, physicians now worked to identify and treat vessel disease to restore meaningful blood circulation. This article explores the development and deployment of a new device resulting from this refocus, the PAssive VAscular EXerciser (PAVAEX) Boot, and its role as a creative response to a previously intractable clinical problem. The PAVAEX Boot, designed in 1933 by vascular surgeons Louis G. Herrmann and Mont R. Reid, was one of the few interventions for PAD at the time. Based on the observation that continuous negative pressure results in vasoconstriction, while short bursts transiently increase blood flow, the PAVAEX Boot utilized intermittent negative pressure to enhance peripheral vascular perfusion. Well-marketed and praised throughout the 1930s, it vanished from public writing and academic literature just 20years later. However, negative pressure wound therapy resurged in the late 20th century, and though its inventors failed to recognize the precedent of the PAVAEX Boot, many of these devices and therapies are rooted in identical theories. We examine why the PAVAEX Boot faded from use and argue that the device remains a crucial advancement in negative pressure therapy.

Practice patterns of peripheral vascular interventions for peripheral artery disease in the office-based laboratory setting versus outpatient hospital

ObjectiveControversy exists regarding the value and limitations of different sites of service for peripheral artery disease treatment. We aimed to examine practice patterns associated with peripheral vascular interventions (PVIs) performed in the office-based laboratory (OBL) vs outpatient hospital site of service using a nationally representative database. MethodsUsing 100% Medicare fee-for-service claims data, we identified all patients undergoing PVI for claudication or chronic limb-threatening ischemia (CLTI) between January 2017 and December 2022. We evaluated the associations of patient and procedure characteristics with site of service using multivariable hierarchical logistic regression. We used multinomial regression models to estimate the relative risk ratios (RRRs) of site of service and intervention type (angioplasty, stent, or atherectomy) and intervention anatomic level (iliac, femoropopliteal, or tibial) after adjusting for baseline patient characteristics and clustering by physician. ResultsOf 848,526 PVI, 485,942 (57.3%) were performed in an OBL. OBL use increased significantly over time from 48.3% in 2017 to 65.5% in 2022 (P < .001). Patients treated in OBLs were more likely to be Black (adjusted odds ratio [aOR], 1.14; 95% confidence interval [CI], 1.11-1.18) or other non-White race (aOR, 1.13; 95% CI, 1.08-1.18), have fewer comorbidities, and undergo treatment for claudication vs CLTI (aOR, 1.30; 95% CI, 1.26-1.33) compared with patients treated in outpatient hospital settings. Physicians with majority practice (>50% procedures) in an OBL were more likely to practice in urban settings (aOR, 21.58; 95% CI, 9.31-50.02), specialize in radiology (aOR, 18.15; 95% CI, 8.92- 36.92), and have high-volume PVI practices (aOR, 2.15; 95% CI, 2.10-2.29). The median time from diagnosis to treatment was shorter in OBLs, particularly for patients with CLTI (29 vs 39 days; P < .001). The OBL setting was the strongest predictor of patients receiving an atherectomy alone (adjusted RRR [aRRR] 6.67; 95% CI, 6.59-6.76) or atherectomy + stent (aRRR, 10.84; 95% CI, 10.64-11.05), and these findings were consistent in subgroup analyses stratified by PVI indication. The OBL setting was also associated with higher risk of tibial interventions for both claudication (aRRR, 3.18; 95% CI, 3.11-3.25) and CLTI (aRRR, 1.89; 95% CI, 1.86-1.92). The average reimbursement (including professional and facility fees) was slightly higher for OBLs compared with the hospital ($8742/case vs $8459/case; P < .001). However, in a simulated cohort resetting the OBL's intervention type distribution to that of the hospital, OBLs were associated with a hypothetical cost savings of $221,219,803 overall and $2602 per case. ConclusionsThe OBL site of service was associated with greater access to care for non-White patients and a shorter time from diagnosis to treatment, but more frequently performed high-cost interventions compared with the outpatient hospital setting. The benefit to patients from improved access to peripheral artery disease care in OBL settings must be balanced with the potential limitations of receiving differential care.

Association of Sex and Trends in Guideline-directed Medical Therapy Use Among Patients Undergoing Intervention for Infrainguinal Peripheral Artery Disease in the Vascular Quality Initiative, 2010-2023

Association of Sex and Trends in Guideline-directed Medical Therapy Use Among Patients Undergoing Intervention for Infrainguinal Peripheral Artery Disease in the Vascular Quality Initiative, 2010-2023

UFM1 inhibits hypoxia-induced angiogenesis via promoting proteasome degradation of HIF-1α

UFM1 inhibits hypoxia-induced angiogenesis via promoting proteasome degradation of HIF-1α

Patient Factors Influencing Prescription of Antithrombotic Medication After Lower Limb Endovascular Intervention

There is significant practice variation in the use of antithrombotic therapy after endovascular intervention for lower limb peripheral arterial disease, with differences in medication choice and duration. Prescriber decision making is complex, and patient factors have been shown to substantially contribute to prescribing variation. To determine the influence of patient factors on antithrombotic prescribing, a discrete choice experiment was distributed to vascular surgeons and trainees across Australia and Aotearoa New Zealand. After pilot testing, the discrete choice experiment questionnaire was distributed to 300 vascular surgeons and trainee members of the Australian and New Zealand Society for Vascular Surgery. Multinomial logistic regression models were used to analyse patient factors that had the most influence on decisions to prescribe a second antithrombotic agent, and the preferred choice of antithrombotic (clopidogrel 75 mg daily or rivaroxaban 2.5 mg twice daily) in addition to aspirin 100 mg daily. The odds ratio (OR) with 95% confidence interval (CI) reported preference strength. A total of 44 questionnaires were completed between September and October 2023, reaching the 15% targeted response rate. Prescribing a second antithrombotic was more likely after femoropopliteal stenting compared with angioplasty (OR 1.89, 95% CI 1.20 - 2.13), and in chronic limb threatening ischaemia compared with intermittent claudication (OR 1.58, 95% CI 1.20 - 2.13). Most respondents preferred clopidogrel over rivaroxaban (62%), with over a third of respondents exclusively prescribing clopidogrel. Patients with stents (OR 1.77, 95% CI 1.32 - 2.37) or moderate bleeding risk (OR 1.38, 95% CI 0.97 - 1.84) were more likely to receive clopidogrel than rivaroxaban. This study demonstrates that vascular surgeons primarily prioritise antithrombotic prescribing decisions by procedure type. Clopidogrel is more likely to be prescribed than rivaroxaban as a second agent in combination with aspirin, especially after stenting. Knowing these clinician preferences can target implementation strategies towards supporting decision making in subgroups of patients according to individual risk profiles.

Intravascular Ultrasound Use is Associated with Improved Patency in Lower Extremity Peripheral Arterial Interventions

ObjectivesIntravascular ultrasound (IVUS) facilitates detailed visualization of endoluminal anatomy not adequately appreciated on conventional angiography. However, it is unclear if IVUS use improves clinical outcomes of peripheral vascular interventions (PVI) for peripheral arterial disease (PAD). This study aimed to evaluate the impact of IVUS on 1-year outcomes of PVI in the vascular quality initiative (VQI). MethodsThe VQI-PVI modules were reviewed (2016-2020). All patients with available one-year follow up after lower extremity PVI were included and grouped as IVUS-PVI or non-IVUS PVI based on use of IVUS. Propensity matching (1:1) was performed using demographics and comorbidities. One-year major amputation and patency rates were compared. A generalized estimating equation (GEE) model was used to identify predictors of 1-year outcomes. Subgroup analysis based on Trans-Atlantic Inter-Society Consensus (TASC) classification, treatment length and treatment modalities were performed using same modeling approaches. ResultsThere were 56,633 procedures (non-IVUS PVI=55,302 vs IVUS-PVI=1,331) in 44,042 patients. Propensity matching yielded a total cohort of 1,854 patients matched (1:1), with no baseline differences. LER for claudication was performed in 60.4%, while one-third (33.9%) had chronic limb threatening ischemia (CLTI). IVUS was more commonly used for lesions >15cm in length (46.6% vs 43.3%) and for aortoiliac disease (31.8% vs 27.2%). Rates of atherectomy and stenting were significantly higher with IVUS-PVI (21.1% vs 16.8%), while balloon angioplasty was less common (13.5% vs 24.4%). One-year patency was better with IVUS-PVI (97.7% vs 95.2%, p=0.004). On subgroup analysis, IVUS (OR 2.20, 95% CI 1.29- 3.75) was associated with improved patency in CLTI patients, TASC C or D lesions, and treatment length >15cm. Adjunctive IVUS use during PVI did not significantly impact 1-year amputation (OR 1.7, 95%CI 0.78-3.91). On multivariable regression, adjunctive use of IVUS (OR 2.46 95%CI 1.43-4.25) and aortoiliac interventions (OR 2.91, 95%CI 1.09-7.75) were independent predictors of patency. Treatment modalities such as atherectomy, stenting or balloon angioplasty did not significantly impact patency at 1-year. ConclusionIVUS during lower extremity PVI is associated with improved 1-year patency, when compared to angiography alone. Certain subgroups, such as CLTI patients, lesions>15cm, and TASC C or D lesions might benefit from adjunctive use of IVUS.

Management and Pharmacological Treatment of Peripheral Arterial Disease.

Background: Peripheral arterial disease (PAD) is a complex, heterogeneous condition that has become a leading health concern globally. Peripheral arterial disease often co-exists with other vascular disease states, including cerebrovascular and cardiovascular disease. Optimal therapy for managing symptoms and progression of disease employs non-pharmacological, pharmacological, and contemporary revascularisation techniques to improve clinical outcomes and quality of life. However, large well-designed randomised control trials (RCT) and corresponding evidence-based guidelines for management of PAD are lacking, with current practice standards often extrapolated from evidence in coronary artery disease.Purpose: This review article aims to discuss currently accepted best pharmacological practice for PAD.Method: Relevant articles were searched between May 2023 and January 2024 through PubMed, Cochrane Library, Google Scholar and international guidelines, focusing on pharmacological management for PAD.Results: This narrative review discusses holistic pharmacological treatments for PAD.

Designing a platform/adaptive randomised controlled trial for peripheral arterial disease (PAD) – The PAEDIS international platform trial development project

Background Peripheral artery disease (PAD) is a common health problem. There are several technologies, medications, and interventions that aim to improve or treat PAD in people with symptomatic disease. Most of these technologies, however, have been untested in high-quality randomised studies assessing effectiveness and their interactions remain unknown. We developed a proposed design for an international randomised controlled trial assessing multiple PAD treatments. Methods Over the course of 11 months (2023) several workshops and reviews of the literature took place. More specific, the proposed platform trial was designed with 44 people with PAD and 112 experts from across the world, in five work packages. The most relevant PAD treatment with unproven effectiveness were identified and key trial components as well as success criteria were defined. With input from five clinical trials units, the final format of a potential platform PAD trial in primary and secondary care was then proposed for funding. Results The proposed platform PAD randomised trial involved two major multi-arm multi-stage randomised studies, assessing PAD treatments in the community setting (1st package) and then secondary care (2nd package). The 1st package involved people with claudication and the 2nd package involves people with chronic limb threatening ischaemia (CLTI). Conclusions A platform PAD trial involves many challenges in terms of both design and delivery. The proposed design involving both people with claudication and CLTI will hopefully act as a blueprint for future work in this area.

MagicTouch PTA Sirolimus-Coated Balloon for Femoropopliteal and Below-the-Knee Disease: 3-Year Outcomes of the XTOSI Trial

ObjectivesSirolimus coated balloon (SCB) is a potential treatment option for peripheral arterial disease (PAD). There is currently no long term clinical data for this novel treatment for PAD. We present the 3 year results of the first-in-human study of MagicTouch PTA SCB for treatment of PAD for both femoropopliteal and below the knee arteries (BTK). MethodsXTOSI pilot study is a prospective, single-arm, open-label, single centre trial evaluating MagicTouch PTA SCB for symptomatic PAD. Assessments through 3 years included freedom from clinically driven target lesion revascularization (CD-TLR), freedom from major amputation, amputation free survival (AFS), overall survival and ulcer free status. ResultsAt 3 years, the overall freedom from CD-TLR was 84.4%, freedom from major amputation was 86.1%, AFS was 63.3%, overall survival was 63.3% and ulcer free status in remaining survivors with intact limbs was 100%.For femoropoliteal lesions, at 3 years, the freedom from CD-TLR was 92.9%, freedom from major amputation was 93.3%, AFS was 70% and overall survival was 70%. For BTK lesions, at 3 years, the freedom from CD-TLR was 77.8%, freedom from major amputation was 81.0%, AFS was 58.6% and overall survival was 58.6%. ConclusionsSCB in the XTOSI pilot study showed promising clinical results sustained to 3 years and no long term safety concerns were raised. Randomized trials are currently ongoing to investigate the safety and efficacy of SCB for treatment of PAD.

20 Characteristics of Medicare patients receiving peripheral vascular interventions for peripheral artery disease differ by outpatient site of service

OBJECTIVES/GOALS: Endovascular peripheral vascular interventions (PVIs) are increasingly utilized for the treatment of peripheral artery disease (PAD). We aimed to assess characteristics of patients receiving PVI at ambulatory surgical centers and office-based labs (ASC/OBL) versus the outpatient hospital (hospital) site of service. METHODS/STUDY POPULATION: We performed a retrospective analysis using 100% Medicare fee-for-service claims data between January 1, 2017 and December 31, 2022. We used Current Procedural Terminology (CPT) codes to identify patients undergoing angioplasty, stenting, or atherectomy. Patient demographics were collected from the Medicare Master Beneficiary Summary File and associated comorbidities and PVI indications were identified using International Classification of Disease (ICD)-10 codes. We used patient ZIP codes to determine patients’ residence densities and regions. We used site of service codes to determine whether PVI were performed in the ASC/OBL versus hospital. Results were analyzed with descriptive statistics. RESULTS/ANTICIPATED RESULTS: Of 817,241 patients undergoing PVI for PAD, 461,068 (56.4%) were treated in an ASC/OBL. Compared to patients treated in the hospital, patients receiving PVI at ASC/OBLs were more likely to be older, female, non-white race, with fewer comorbidities (end stage renal disease, diabetes, hypertension, and any history of tobacco use) (all, P&lt;0.001). Patients treated in ASC/OBLs more frequently resided in urban (vs. rural) locations, and in the South and West (both, P&lt;0.001). Indication for PVI was predominately chronic limb-threatening ischemia, and clinically similar between groups (77.1% vs. 76.2%). There was a significant change in site of service over time: a minority (47.6%) of PVIs were performed in the ASC/OBL in 2017, whereas the majority (64.7%) of PVIs were performed in the ASC/OBL in 2022 (P&lt;0.001). DISCUSSION/SIGNIFICANCE: Patients treated in ASC/OBLs were less medically complex compared to those treated in the outpatient hospital setting. Further study is needed to examine whether differences in patient characteristics versus other factors (e.g. reimbursement) are driving the increase in PVIs performed in the ASC/OBL over time.

Six-month combined aerobic and resistance exercise program enhances 6-minute walk test and physical fitness in people with peripheral arterial disease: A pilot study

BackgroundExercise therapy is a recognized non-pharmacological intervention for peripheral arterial disease (PAD); however, the effects of combined exercise remain under investigation. This study aimed to compare the effects of a 6-month combined supervised exercise program (SUP) with a usual care (UC) approach on walking ability, physical fitness, and peripheral blood flow in people with PAD and claudication. MethodsTwenty-three male participants (Age=64.1 ± 6.2years and ABI=0.58±0.07) with PAD and claudication were assigned to either the SUP group (n = 10), engaging in structured supervised treadmill walking combined with three resistance exercises, three times a week, or the UC group (n = 13), receiving advice to walk. The primary outcome measure was walking ability, with assessments conducted at baseline (M0), after 3 months (M3), and 6 months (M6). ResultsAfter the 6-month intervention, the SUP group exhibited significant improvements in absolute claudication time (ACT, p = 0.045), maximal walking time (MWT, p = 0.045), maximal walking distance (MWD, p = 0.027), and pause duration (p = 0.045) during the 6-minute walk test (6MWT), when compared to the UC group. Over time, a significant increase in walking speed during the 6MWT (Speed6MWT, p = 0.001) and walking speed without claudication (SpeedNoC, p < 0.001) was found, although no significant differences were found between the groups. The SUP group increased by 0.8 km/h in both Speed6MWT and SpeedNoC, while the UC group increased by 0.3 km/h and 0.6 km/h, respectively. Despite claudication consistently occurring at the same time, the SUP group demonstrated an improved tolerance to pain or a better understanding of pain, enabling them to walk longer distances at higher speeds. A positive effect of SUP was found for chair sit-and-reach test (p = 0.023), percentage of fat mass (p = 0.048), fat-free mass (p = 0.040), and total body water (p = 0.026), suggesting potential benefits attributed to the resistance strength exercises. ConclusionA 6-month combined treadmill and resistance exercise program improved walking ability, walking speed, lower body and lower back flexibility, and body composition in people with PAD and claudication.

Evaluation of Computerized Tomography Utilization in Comparison to Digital Subtraction Angiography in Patients with Peripheral Arterial Disease

ObjectivesPerform literature review to analyze current practices in imaging patient with peripheral arterial disease (PAD) and examine patterns in our practice in order to assess whether a lower extremity computed tomography angiography (CTA) in addition to digital subtraction angiography (DSA) enhanced the assessment of vessel calcification, percentage of stenosis; and affected outcomes in patients with peripheral arterial disease. Methods and MaterialsThe study included patients who underwent lower extremity imaging and were followed up to 12 months. This population was divided into cases who had both an angiogram and CTA performed within 30 days (n=20), and controls who underwent angiography only (n=19). Baseline characteristics, imaging results, and clinical outcomes were analyzed. ResultsThirty-nine patients met study criteria (mean age was 58.4 years, 69.2% were males, and 33.3% had diabetes). Patients mostly presented with tissue loss/rest pain (10.3%), claudication (15.4%), acute limb (10.3%), and trauma (15.4%). We have not observed any statistically significant differences in various examined blood vessels when their features (e.g. vessel diameter, stenosis, calcifications) were assessed by CTA combined with angiography versus angiography alone. The exceptions were external iliac artery, superficial femoral artery and dorsalis pedis vessels. In external iliac artery percentage of stenosis was 1.11% as determined by CT scan versus 30% by angiography (P=.009). For superficial femoral artery stenosis the percentage determined by CT was 48.68% versus 81.41% by angiography, and observed difference between two modalities was statistically significant (P=.025). For dorsalis pedis percentage of stenosis detected by CT scan was 60.63% versus 22.73% by angiography, and the differences in findings by these modalities were statistically significant (P=.039). The most frequent perioperative complication was cardiac-related (35.5%). Nineteen patients were readmitted and 8 had re-interventions within 12 months. ConclusionBoth imaging modalities yielded similar results for assessing vessel calcification and percentage of stenosis regardless of anatomic vessel location. Overall, utilization of CTA in addition to angiography for large vessels above the knee (e.g. iliac artery, superficial femoral artery) and below the knee for dorsalis pedis provided more detailed information on the properties of these vessels. Therefore, during pre-operative assessments, CTA may be helpful in addition to angiography for planning surgical and endovascular interventions for symptomatic PAD treatment in larger vessels.

Artificial Intelligence to Predict Quality-of-Life Outcomes for Vascular Intervention of the Leg.

Artificial intelligence (AI) tools created to enhance decision-making may have a significant impact on treatment algorithms for peripheral arterial disease (PAD). A Markov-based AI model was developed to predict optimal therapy based on maximization of calculated quality of life (cQoL), a patient-centered system of assessment designed to report outcomes directly linked to health-related quality of life. The AI model was prospectively interrogated immediately after individual interventions for PAD over a 12-year period to test predictive performance. Patient cQoL was determined at each patient follow-up visit. A total of 1,143 consecutive patients were evaluated, with a median follow-up of 18 months. Observed mean annualized cQoL was higher than predicted by the model (0.85 ± 0.38 vs 0.79 ± 0.18, p < 0.0001). Of 5 potential clinical outcomes, the AI model correctly predicted final status in 71.3% of patients, with insignificant model performance deterioration over time (-0.15% per month, r = -0.49, p = 0.063). The chance of having the condition predicted by the model was 0.57 ± 0.32, compared with a theoretical maximum of 0.70 ± 0.19 (p < 0.0001, mean ratio 0.79). The AI model performed better in patients with claudication than limb-threatening ischemia (75.5% vs 63.6%, p = 0.014) but equally well for open or endovascular intervention (69.8% vs 70.5%, p = 0.70). Graft or artery patency and amputation-free survival were better for patients with claudication and those treated with endovascular techniques. AI can successfully predict treatment for PAD that maximizes patient quality of life in most cases. Future application of AI incorporating better estimates of patient anatomic and physiological risk factors and refinement of model structure should further enhance performance.

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

Endovascular intervention for peripheral artery disease (PAD) carries nonnegligible perioperative risks; however, outcome prediction tools are limited. To develop machine learning (ML) algorithms that can predict outcomes following endovascular intervention for PAD. This prognostic study included patients who underwent endovascular intervention for PAD between January 1, 2004, and July 5, 2023, with 1 year of follow-up. Data were obtained from the Vascular Quality Initiative (VQI), a multicenter registry containing data from vascular surgeons and interventionalists at more than 1000 academic and community hospitals. From an initial cohort of 262 242 patients, 26 565 were excluded due to treatment for acute limb ischemia (n = 14 642) or aneurysmal disease (n = 3456), unreported symptom status (n = 4401) or procedure type (n = 2319), or concurrent bypass (n = 1747). Data were split into training (70%) and test (30%) sets. A total of 112 predictive features (75 preoperative [demographic and clinical], 24 intraoperative [procedural], and 13 postoperative [in-hospital course and complications]) from the index hospitalization were identified. Using 10-fold cross-validation, 6 ML models were trained using preoperative features to predict 1-year major adverse limb event (MALE; composite of thrombectomy or thrombolysis, surgical reintervention, or major amputation) or death. The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). After selecting the best performing algorithm, additional models were built using intraoperative and postoperative data. Overall, 235 677 patients who underwent endovascular intervention for PAD were included (mean [SD] age, 68.4 [11.1] years; 94 979 [40.3%] female) and 71 683 (30.4%) developed 1-year MALE or death. The best preoperative prediction model was extreme gradient boosting (XGBoost), achieving the following performance metrics: AUROC, 0.94 (95% CI, 0.93-0.95); accuracy, 0.86 (95% CI, 0.85-0.87); sensitivity, 0.87; specificity, 0.85; positive predictive value, 0.85; and negative predictive value, 0.87. In comparison, logistic regression had an AUROC of 0.67 (95% CI, 0.65-0.69). The XGBoost model maintained excellent performance at the intraoperative and postoperative stages, with AUROCs of 0.94 (95% CI, 0.93-0.95) and 0.98 (95% CI, 0.97-0.99), respectively. In this prognostic study, ML models were developed that accurately predicted outcomes following endovascular intervention for PAD, which performed better than logistic regression. These algorithms have potential for important utility in guiding perioperative risk-mitigation strategies to prevent adverse outcomes following endovascular intervention for PAD.

Illness beliefs relation to physical activity and quality of life in patients with peripheral arterial disease

ABSTRACT Intermittent claudication is the most common symptom of Peripheral Arterial Disease (PAD) and is associated with decreased quality of life (QoL) due to walking impairment. The level of threat attributed to the disease affects QoL and physical activity. This study explores beliefs and illness drawings, and their relationship with quality of life and physical activity in patients undergoing conservative treatment for PAD. A cross-sectional study was carried out including 119 patients with PAD and Intermittent Claudication, in which patients were asked to freely draw their disease and 33 agreed to participate. The profile of beliefs about PAD is characterized by a low level of threat. Belief in the emotional impact of the disease, representations about the consequences and concern about the disease were associated with worse quality of life; the belief of having a high personal control over the disease was associated with more physical activity. The analysis of the disease drawings revealed three categories: extension of the disease (category 1), location and representations of the disease (category 2), and level of detail and complexity of the drawings (category 3). Greater disease extent was associated with more disease symptoms (IPQ 6) (r s = 0.399, p = .021). It is necessary to address beliefs and representations about the disease in consultations with patients with PAD. Patient drawings are a useful, practical, and free tool that does not require a lot of time and can facilitate the approach of health professionals to patient training and education.

Prescriber decision-making on antithrombotic therapy after endovascular intervention for peripheral artery disease: a protocol for a discrete choice experiment

IntroductionPeripheral artery disease (PAD) is a major risk factor for cardiovascular morbidity and mortality, despite surgical and endovascular treatments. Emerging evidence supports the use of immediate antithrombotic medications after endovascular...

Short-term outcomes of endovascular management of acute limb ischemia using aspiration mechanical thrombectomy.

Management of acute limb ischemia (ALI) has seen greater utilization of catheter-based interventions over the last two decades. Data on their efficacy is largely based on comparisons of catheter-directed thrombolysis (CDT) and open thrombectomy. During this time, many adjuncts to CDT have emerged with different mechanisms of action, including pharmacomechanical thrombolysis (PMT) and aspiration mechanical thrombectomy (AMT). However, the safety and efficacy of newer adjuncts like AMT have not been well established. This study is a retrospective analysis of the contemporary management of ALI comparing patients treated with aspiration mechanical thrombectomy to patients treated with the more established CDT adjunct, pharmacomechanical thrombolysis. Patients undergoing peripheral endovascular intervention for ALI using an adjunctive device were identified through query of the Vascular Quality Initiative (VQI) Peripheral Vascular Intervention (PVI) module from 2014 to 2019. Patients with a nonviable extremity (Rutherford ALI Stage 3), prior history of ipsilateral major amputation, popliteal aneurysm, procedures that were deemed elective (>72h from admission), procedures that did not utilize an endovascular adjunctive device, and patients without short-term follow-up were all excluded from analysis. The primary outcome was a composite outcome of freedom from major amputation and/or death in the perioperative time period. We identified 528 patients with Rutherford ALI Stage 1 or 2 who were treated with an endovascular adjunct. 433 patients did not undergo aspiration mechanical thrombectomy (no AMT group) and 95 patients did undergo aspiration mechanical thrombectomy (AMT group). The amputation-free survival across all patients was 93.4%. There were significant differences in demographic, comorbidity, and treatment variables between groups (e.g., gender, prior percutaneous coronary intervention (PCI), history of prior peripheral artery disease intervention, and history of prior infra-inguinal PVI), so a propensity score matched analysis was included to account for these group differences. In the propensity score matched analysis, there was no significant difference in major amputation (AMT 7.4% vs no AMT 3.2%, p = 0.13) or death (AMT 95.8% survival vs no AMT 98.4% survival, p = 0.23) with the use of aspiration mechanical thrombectomy. However, there was significantly worse amputation-free survival with the use of aspiration mechanical thrombectomy (AMT 88.4% vs no AMT 95.3%, p = 0.03). On multivariate analysis, prior supra-inguinal bypass (OR 4.85, 1.70-13.84, p = 0.003), Rutherford ALI Stage 2B (OR 3.13, 1.47-6.67, p = 0.003), and aspiration mechanical thrombectomy (OR 2.71, 1.03-7.17, p = 0.05) were associated with the composite outcome. Short-term amputation-free survival rates of endovascular management of acute limb ischemia are adequate across all modalities. However, aspiration mechanical thrombectomy was associated with significantly worse amputation-free survival compared to other endovascular adjuncts alone (i.e., pharmacomechanical thrombolysis). Severe limb ischemia (Rutherford ALI Stage 2B) and prior supra-inguinal bypass were associated with worse amputation-free survival regardless of the choice of endovascular intervention.