Baseline modern medical management in the BEST-CLI trial

Markers of optimal medical therapy are associated with improved limb outcomes after elective revascularization for intermittent claudication

BACKGROUND

Optimal medical therapy (OMT) is a modifiable factor that decreases mortality and cardiovascular events in patients with severe peripheral arterial disease. We hypothesized that preintervention OMT would be associated with improved 1-year reintervention and major adverse limb event (MALE) rates after elective endovascular revascularization for intermittent claudication (IC).

METHODS

Using the Vascular Quality Initiative (2010-2020), we identified patients with IC undergoing elective endovascular, hybrid, and open surgical interventions. Preoperative antiplatelet, statin, and nonsmoking status defined OMT components and created three groups: complete (all components), partial (1-2 components), and no OMT. The primary outcome was 1-year reintervention. Secondary outcomes included MALE and factors associated with OMT usage. Multivariable logistic regression generated adjusted odds ratios (aOR).

RESULTS

There were 39,088 patients (14,907 [38.1%] complete, 22,054 [56.4%)] partial, 2127 [5.4%] no OMT) who met our criteria. Patients with any OMT were more frequently older with more cardiovascular diseases and diabetes (P < .0001). Patients without OMT were more likely to be Black or with Medicare or Medicaid (P < .05). Observed 1-year reintervention (5.3% complete OMT, 6.1% partial OMT, 8.3% no OMT; P < .001) and MALE (5.6% complete OMT, 6.3% partial OMT, 8.8% no OMT; P < .001) were decreased by partial or complete OMT compared with no OMT. Complete OMT significantly decreased the adjusted odds of reintervention and MALE by 28% (aOR, 0.72, 95% confidence interval [95% CI], 0.59-0.88) and 30% (aOR, 0.70; 95% CI, 0.58-0.85), respectively, compared with no OMT. Partial OMT decrease the adjusted odds of reintervention and MALE by 24% (aOR, 0.76; 95% CI, 0.63-0.92) and 26% (aOR, 0.74; 95% CI, 0.62-0.89), respectively.

CONCLUSIONS

Preintervention OMT is an underused, modifiable risk factor associated with improved 1-year reintervention and MALE. Vascular surgeons are uniquely positioned to initiate and maintain OMT in patients with IC before revascularization to optimize patient outcomes.

Evaluating Receipt of Optimal Medical Therapy Among Structurally Disadvantaged Groups Undergoing Amputation

BACKGROUND

Optimal medical therapy (OMT) for peripheral artery disease (PAD) is associated with decreased major amputation and mortality. OMT has several components, including antiplatelet and high-intensity statin therapy, blood pressure control, etc. While there are disparities in receipt of OMT among PAD patients, it is unknown if patients from disadvantaged neighborhoods, measured by the area deprivation index (ADI), are less likely to be on OMT.

METHODS

We performed a retrospective review of patients that underwent major lower extremity amputation between 2015 and 2019 at 2 large academic healthcare systems. Primary exposure was high ADI, defined as ADI ≥60th percentile, and secondary exposure was non-Hispanic Black (NHB) race. For each analysis, the primary outcome of interest was receipt of OMT, defined here as at least one antiplatelet agent and a high-intensity statin. The exposure outcome relationship was assessed using multivariable logistic regression.

RESULTS

Among 354 patients with median age of 66 (interquartile range [IQR] 58-74), 267 (75.4%) were male, 219 (61.9%) identified as NHB and 116 (32.8%) as non-Hispanic White (NHW). Overall, 91 (25.7%) patients were on OMT at time of amputation despite 57.3% of the cohort being established with a vascular surgeon. Compared to those with low ADI, the category high ADI had a higher proportion of NHB patients (48.1% vs 70.3%, P = 0.001) and patients were more often hospitalized at the University-affiliated facilities (47.4% vs 63.0%, P = 0.004). High ADI was not associated with receipt of OMT prior to major amputation (adjusted odds ratio [aOR] 0.72, 95% confidence interval [CI] 0.42-1.24). In secondary analysis, NHB race was not associated with receipt of OMT. Stratification by facility type (Veterans Affairs and University-affiliated facilities) also showed no association between high ADI or race and receipt of OMT.

CONCLUSIONS

Neighborhood economic well-being is not associated with receipt of OMT prior to major amputation. While the absence of socioeconomic disparities is notable, the proportion of patients on OMT is suboptimal. Care processes should be critically evaluated and quality measures potentially created to improve the rate of receipt of OMT among patients at risk for amputation.

The Impact of Follow-Up on Mortality in Chronic Limb-Threatening Ischemia

BACKGROUND

Chronic limb-threatening ischemia (CLTI) is associated with high morbidity and mortality. As such, close follow-up is recommended to ensure patency of revascularization, limb viability, and optimization of cardiovascular risk factors. This study aimed to test the association between follow-up adherence and mortality, and to identify risk factors for nonadherence with recommended vascular follow-up.

METHODS

All patients hospitalized from 2019 to 2023 with infrainguinal CLTI and at least 30 days of posthospitalization survival were included. Patients were stratified based on adherence with any outpatient vascular follow-up within 1 year defined as any outpatient visit conducted after the index hospitalization in which CLTI of the index limb was addressed. The primary endpoint was 1-year mortality and risk factors for follow-up nonadherence were assessed to identify targets for improvement. Multivariable models adjusted for other relevant contributors to mortality including age, clinical comorbidities, medical therapies, and anatomic/clinical limb severity among others. Additional sensitivity analyses were conducted using various definitions of follow-up adherence to enhance reliability of the findings.

RESULTS

A total of 131 patients with a median age of 73 years were included. A majority had tissue loss (97, 74.1%), 118 (90.1%) underwent index revascularization and 13 (9.9%) received no intervention due to nonsalvageable disease or patient preference. The overall 1-year mortality rate was 19.8% and follow-up adherence was 83.2%. Nonadherence with vascular follow-up was associated with greater 1-year mortality (40.9% vs. 15.6%, odds ratio (OR) 6.67, P = 0.005), a finding which persisted when all definitions of follow-up were tested. Risk factors for follow-up nonadherence include transfer from another institution (30.2% vs. 10.2%, OR 3.704, P = 0.014) and lack of a primary care provider (66.7% vs. 11.8%, OR 14.603, P < 0.001).

CONCLUSIONS

Nonadherence with vascular follow-up is associated with higher 1-year mortality among patients with CLTI. Improved referral of CLTI patients to a vascular surgeon in the outpatient setting before the need for urgent interhospital transfer as well as care coordination through a primary care provider may help improve adherence with vascular follow-up.

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.

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.

Establishing a Critical Limb Ischemia Outpatient Center: Separating Facts from Myth

Critical Limb Ischemia or chronic limb-threatening ischemia represents the end stage of peripheral artery disease where arterial flow is compromised to the lower extremities and risk of limb loss may become imminent. Revascularization of lower extremities is one of the cornerstones of limb salvage and amputation prevention. Establishing centers of high quality CLI therapy requires creating different foundational pillars in order to be successful. This article discusses critical limb ischemia center creation from the perspective of critical limb ischemia therapists working in an outpatient setting.

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.