Baseline modern medical management in the BEST-CLI trial

Real-world use of medical therapy in moderate asymptomatic carotid stenosis

OBJECTIVE

Despite level 1 evidence demonstrating the benefit of carotid endarterectomy for the prevention of stroke in patients with severe asymptomatic carotid stenosis (ACS), there has been a trend toward recommending optimal medical therapy (OMT) alone. This recommendation has been promulgated based on the observation that modern advances in OMT reduce the overall stroke risk in the general population, but the success of this treatment strategy is dependent on patient and provider adherence. In current practice, patients with moderate ACS are nearly all treated with OMT alone. The objective of this study was to evaluate adherence to OMT in a cohort of patients with moderate ACS undergoing treatment with OMT alone.

METHODS

Consecutive carotid duplex ultrasound examinations were reviewed for the years 2019 and 2020. Those with moderate (50%-69%) ACS based on Society for Vascular Surgery guidelines were included in the study. Patients were assessed for OMT at the time of the index duplex, the first follow-up visit, and at each subsequent follow-up visit until the end of the study. OMT was defined as abstinence from smoking, aspirin or other antiplatelet use, and statin or other lipid-lowering therapy. Patients were stratified based on their ability to achieve OMT, and each component was evaluated to identify shortfalls in therapy.

RESULTS

A total of 323 duplex ultrasound examinations with moderate ACS in 255 patients were identified. Of the 255 patients, 143 (56.1%) were on OMT at the time of the first duplex; that number increased to 163 (63.9%) by the first follow-up visit and 175 (68.6%) by the completion of the study. There were 112 (43.9%) patients who were not on OMT at the time of the index duplex, 43 (38.4%) of whom achieved OMT over a median follow-up time of 2.7 years. By the end of follow-up, 86 (76.8%) were taking aspirin or another antiplatelet medication, 93 (83.0%) were on statin or other lipid-lowering therapy, and 74 (66.1%) were abstinent from smoking. Pre-duplex smoking was independently associated with failure to achieve OMT (hazard ratio: 0.452, P = .017).

CONCLUSIONS

Among patients with moderate ACS who were not previously on OMT, the rate of OMT achievement is poor. Although advances in lipid management through statin therapy have been praised for their role in improving the effectiveness of OMT, smoking cessation represents an important target for improving uptake and as a result effectiveness of OMT.

Educating Trainees to Treat Peripheral Arterial Disease: Challenges and Opportunities

Educating trainees to treat Peripheral Artery Disease (PAD) carries specific contemporary challenges. The national increase of the prevalence of PAD combined with a significant shortage of vascular surgeons creates a need for concern for future management of this complex disease. Over the past 2 decades, traditional (5 + 2) and integrated (0 + 5) paradigms have fostered trainee annual growth and comparable case distribution and volumes in endovascular and open surgical treatment options have been maintained. Close evaluation into not only the absolute numbers of surgical cases, but the level of trainee involvement in each logged case is recommended. Future implementation of the Entrustable Professional Activity (EPA) modules will hopefully assist in ensuring linear development of surgical skill and judgment. Additionally, advances in individual and systems level techniques to enhance skill acquisition in the form of "off-the job training" and simulation-based training may provide an enhancement to traditional technical training methods. Finally, the possibility and role of artificial intelligence in vascular surgery skill training must not be ignored, but carefully explored and utilized to modernize cognitive and technical skill preparation for trainees in the and delivery of care for PAD patients. Overall, the training residents for the treatment of PAD patients will be associated with new challenges that vascular surgery must embrace and surmount to advance our specialty.

Using machine learning to predict outcomes following suprainguinal bypass

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Disparities in Diagnosis, Treatment, and Outcomes of Peripheral Artery Disease: JACC Scientific Statement

Disparities by sex, race, socioeconomic status, and geography exist in diagnosis, treatment, and outcomes for people with lower extremity peripheral artery disease (PAD). PAD prevalence is similar in men and women, but women have more atypical symptoms and undergo lower extremity revascularization at older ages compared to men. People who are Black have an approximately 2-fold higher prevalence of PAD, compared to people who are White and have more atypical symptoms, greater mobility loss, less optimal medical care, and higher amputation rates. Although fewer data are available for other races, people with PAD who are Hispanic have higher amputation rates than White people. Rates of amputation also vary by geography in the United States, with the highest rates of amputation in the southeastern United States. To improve PAD outcomes, intentional actions to eliminate disparities are necessary, including clinician education, patient education with culturally appropriate messaging, improved access to high-quality health care, science focused on disparity elimination, and health policy changes.