Abstract 4364866: Incidental Peripheral Calcifications on Computed Tomography in Patients Post-PCI Predict Poor Long-Term Outcomes

Abstract

Introduction: Peripheral artery disease (PAD) is an underrecognized and undertreated condition associated with significant cardiovascular morbidity and mortality. Peripheral calcifications on computed tomography (CT) are often incidental markers of atherosclerosis, yet are rarely linked to formal PAD evaluation. We examined a cohort of patients post percutaneous coronary intervention (PCI) with incidentally noted peripheral calcifications on CT to assess the prognostic impact of risk factors and diagnostic practices on long-term outcomes. Methods: This is a multi-hospital retrospective study of 2,397 patients who underwent PCI between 2012-2019. Patients with non-contrast CT imaging of the abdomen and pelvis within six months of PCI were evaluated for calcifications in the abdominal aorta and/or iliac arteries. Those without relevant imaging or with prior PAD diagnosis were excluded, leaving 1,135 patients in the final cohort. Baseline demographics, comorbidities, ankle-brachial index (ABI) testing, medical therapy, and incidence of limb and cardiovascular events were assessed. Composite limb events included amputation, revascularization, angioplasty, endarterectomy, and bypass. Results: Among the final cohort, 36% were female, average age was 68, and 90% were White. Five-year Kaplan-Meier estimated event rates were 20.2% (95% CI 17.9–22.6) for all-cause mortality and 6.4% (95% CI 5.1–8.0) for composite limb events. ABI testing was performed in only 29% of patients, with abnormal results (ABI<0.9) in 35% of those tested. Using multivariable Cox models, heart failure (HR 2.3, 95% CI 1.8–2.9) and chronic kidney disease (HR 1.8, 95% CI 1.3–2.3) were independently associated with all-cause mortality (p<0.001). ABI <0.9 was significantly associated with composite limb events (HR 5.7, 95% CI 3.3–9.9) and myocardial infarction (HR 2.1, 95% CI 1.4–3.2). Use of evidence-based therapies declined over time, with fewer than 50% on statins or antiplatelets by year 5. Only 23% of patients were referred to vascular surgery for consultation. Conclusion: In this high-risk cohort with peripheral calcifications on CT, few had ABI testing to assess for PAD and less than 25% were referred to vascular surgery. Despite substantial long-term risks of mortality and limb events, use of evidence-based therapies declined over time. Routine clinical screening for PAD in such patients represent a key opportunity for early detection and intervention including optimization of medical therapy.