Impact of 6-Month Angiographic Restenosis Inside Bare-Metal Stents on Long-Term Clinical Outcome in Patients With Coronary Artery Disease

Abstract

This study enrolled 536 patients who underwent successful coronary stenting with bare-metal stents and 6-month angiographic follow-up examinations between 1998 and 2000. Baseline characteristics and angiographic and procedural parameters for these patients were obtained. Primary endpoints were all-cause mortality and nonfatal myocardial infarction. Patients were assigned to instent restenosis or non-instent restenosis groups based on 6-month angiographic follow-up results. Restenosis inside a bare-metal stent was defined as more than 50% stenosis at the intervention site. In total, 178 (33.2%) patients had restenosis inside bare-metal stents, while 358 (66.8%) patients were without. At mean follow-up of 56.8 ± 20.3 months, 36 (6.7%) patients had a primary endpoint event while 500 (93.3%) patients had no primary endpoint event. Survival rates for patients free from primary endpoints in the instent restenosis and non-instent restenosis groups were 96.0 versus 99.4% at 1 year and 89.8% versus 94.8% at 5 years, respectively (P = 0.0033). Survival rates for patients free of all-cause mortality in the instent restenosis and non-instent restenosis groups were 96.0% versus 99.4% at 1 year and 91.6% versus 96.3% at 5 years, respectively (P = 0.0079). Multivariate Cox regression analysis showed that restenosis inside bare-metal stents was an independent predictor of primary endpoint events (odds ratio: 2.053; 95% CI: 1.048-4.022; P = 0.036) and was a predictor of total mortality with borderline significance (odds ratio: 2.036; 95% CI: 0.936-4.431; P = 0.073). In conclusion, in this study, restenosis inside bare-metal stents at 6-month angiographic follow-up was an independent predictor of long-term outcome-all-cause mortality and nonfatal myocardial infarction. Thus, this study provides clinical evidence that patients with restenosis inside bare-metal stents at 6-month angiographic follow-up likely warrant aggressive follow-up.