Factors predictive of cardiac events and restenosis after sirolimus-eluting stent implantation in small coronary arteries

Objectives: Predictors of cardiac events and restenosis after sirolimus-eluting stent (SES) implantation in small coronary arteries were evaluated. Background: Although SES implantation has markedly reduced the risk of restenosis, small vessel disease remains a major cause of SES failure. Methods: We prospectively investigated the factors predictive of cardiac events and restenosis in 1,092 consecutive patients who received SES implantation for 1,269 lesions in small coronary arteries (≤2.8 mm). Follow-up angiography at 8 months was performed in 751 patients with 889 lesions (follow-up rate 70.3%). Results: Restenosis (diameter stenosis ≥ 50%) was angiographically documented in 65 patients with 77 lesions (8.7%): 55 focal (71.4%), 8 diffuse (10.4%), 2 diffuse proliferative (2.6%), and 12 total (15.6%). Lesion length, stent length, reference artery size, and in-stent restenotic lesions were univariate predictors of restenosis. By multivariate analysis, lesion length (OR 1.04; 95% CI 1.02-1.05; P < 0.001) and in-stent restenotic lesions (OR 3.38; 95% CI 1.80-6.35; P < 0.001) were significant independent predictors of restenosis. During follow-up (23.2 ± 7.9 months), there were 17 deaths (5 cardiac and 12 noncardiac), 5 nonfatal Q-wave myocardial infarctions, and 42 target lesion revascularizations. The cumulative probability of survival without major adveres cardiac events (MACE) was (96.8 ± 0.6)% at 1 year and (95.1 ± 0.7)% at 2 years. In multivariate analysia, lesion length (HR 1.04; 95% CI 1.01-1.07; P = 0.004) and in-stent restenotic lesions (HR 3.29; 95% CI 1.58-6.88; P = 0.001) were independently related to MACE. Conclusions: SES implantation in small coronary arteries is safe and effective, with lesion length having a major impact on restenosis and MACE.