IYSC05 - Medication nonadherence and outcomes following lower extremity endovascular revascularization.

Objectives: Medical management of peripheral artery disease (PAD) consists of antiplatelet therapy, cholesterol reduction, blood pressure control, and anticoagulation. These medications are associated with lower mortality, improved quality of life, and fewer adverse limb events in patients with PAD. However, few studies have examined medication adherence rates, the factors that influence them, and the subsequent impact on outcomes.

Methods: We identified all patients who underwent lower extremity endovascular revascularization for PAD between 1/1/23-8/30/24. Pharmacy dispense reports were utilized to calculate proportion of days covered (PDC) for 90 days postoperatively for antiplatelet agents, anticoagulants, statins, anti-hypertensives, insulin, and other anti-hyperglycemic agents. Logistic regression was used to evaluate the factors associated with non-adherence (defined as composite adherence less than 80%), and the association between non-adherence and reintervention, minor and major amputation, and 90-day mortality.

Results: There were 405 patients in our study population; 45% were female, 67% non-White, 39% Hispanic, 18% current smokers, 22% with claudication, 78% with chronic limb-threatening ischemia (CLTI). Only 62% of patients met criteria for composite medication adherence. Half of our population were either on Medicaid or dual-eligible. Non-adherence rates for individual medications ranged from 21.7% for sulfonylureas to 54.1% for short-acting insulin. Patients with CLTI had 44% lower composite medication adherence [OR 0.56 [0.31-1.99], p = 0.051]. However, insurance status and area deprivation index (ADI) were not associated with medication adherence. Ninety-seven patients underwent reintervention (24%), 68 (17%) underwent minor amputation and 39 (10%) underwent major amputation, 149 (37%) were readmitted within 90d, and 16 (4%) died within 90 days. Medication adherence was associated with 61% lower risk for reintervention [sHR 0.39, CI: 0.27-0.58, p < 0.001], 56% lower risk for major amputation [sHR 0.44, CI: 0.23-0.84, p = 0.01], and 45% lower risk for minor amputation [sHR 0.55, CI: 0.34-0.90, p = 0.02].

Conclusions: Medication non-adherence following lower extremity revascularization is common and significantly increases the risk of reintervention and major/minor amputation. Patients with CLTI comprise a high-risk group for nonadherence and have high rates of reintervention and amputation. Notably, however, traditionally accepted risk factors such as ADI and insurance were not associated with adherence, suggesting that significant work remains to understand the reasons for nonadherence as well as improve compliance.