Abstract 12934: The Impact of Peripheral Artery Disease Assessed by Ankle-Brachial Index on Endothelial Dysfunction and Risk of In-Stent Restenosis After Percutaneous Coronary Intervention

Abstract

Introduction: The problem of in-stent restenosis (ISR) after percutaneous coronary intervention (PCI) remains unresolved. Patients with peripheral artery disease (PAD), defined as a decreased ankle brachial index (ABI), have high cardiovascular event rates and impaired endothelial function predicts future cardiovascular events. However, to our knowledge, no studies have assessed the relationship among ABI, endothelial dysfunction, and ISR after PCI. Hypothesis: We assessed the hypothesis that low ABI at PCI is associated with a high incidence of ISR. Methods: ABI and endothelial function were checked before PCI and at follow-up (F/U) angiography in 243 consecutive patients who had successful PCI. Endothelial function was assessed by measuring the reactive hyperemia index (RHI) from fingertip using a RH-PAT device. Patients were categorized according to their ABI values (PAD: ABI≦0.9, borderline: 0.9<ABI50% at F/U angiography assessed by quantitative coronary angiography. Results: Within the study population there were 27 PAD, 26 borderline, and 190 normal ABI at the index PCI. Among them, ISR was demonstrated in 68 patients (28%). As the PAD status become worse, patients were found to have significantly higher ISR rate (PAD: 52%, borderline: 35%, normal: 24%, p=0.02) and more impaired peripheral endothelial function assessed by RHI (PAD: 1.49±0.44, borderline: 1.77±0.41, normal: 1.97±0.52, p=0.0001). Furthermore, patients with ISR were found to have significantly lower ABI than those without ISR (1.05±0.15 vs. 1.11±0.13 p=0.004). By multivariate logistic regression analysis even after adjusting for other significant parameters in univariate analysis (BMS use, Calcium antagonist use, MLD post PCI, Total stent length, right coronary artery stenting, current smoking, HDL-Cholesterol, and ACS presentation), PAD proved to be the independent predictor of ISR (Odds ratio 3.32; 95% confidence interval; 1.29 to 8.54, p=0.01). Conclusions: In patients undergoing PCI, PAD is independently associated with a higher rate of subsequent ISR. Impaired endothelial dysfunction may contribute to this adverse outcome. These findings have important implications for the careful F/U of PAD patients undergoing PCI as ISR-prone patients.