Abstract 12267: Clinical Significance of Very Late Ischemic and Bleeding Events After Percutaneous Coronary Intervention

Abstract

Background: Ischemic and bleeding events following percutaneous coronary intervention are associated with increased mortality, but the prognosis of events occurring beyond 1 year is unknown. Methods: The Dual Antiplatelet Therapy study randomized 11,648 subjects following percutaneous coronary intervention who completed 12 months of dual antiplatelet therapy to either continued thienopyridine plus aspirin treatment for another 18 months versus aspirin therapy alone. Subjects were followed for 21 months after randomization. Ischemic events were defined as Academic Research Consortium definite or probable stent thrombosis, myocardial infarction, ischemic stroke and other cardiovascular deaths. Bleeding events were defined by GUSTO classification (moderate or severe). Kaplan-Meier methods were used to estimate the cumulative incidence of death (regardless of cause) following ischemic and bleeding events over the full study follow-up. Results: At 21 months after randomization, 566 (4.9%) patients had ischemic events and 232 (2.0%) patients had bleeding events. Of the ischemic events, 58.8% were myocardial infarctions, 16.4% were stent thromboses and 12.8% were other cardiovascular deaths. Of all myocardial infarctions and stent thromboses, 8 (2.0%) were fatal on presentation. Among bleeding events, 66.0% were moderate and 34.0% were severe. Of all bleeding events, 3 (1.3%) were immediately fatal. In patients with ischemic events, 24.7% died, and the cumulative incidence of death preceded by an ischemic event was greater following myocardial infarction (0.39%) compared with stent thrombosis (0.13%) and ischemic stroke (0.11%). Among patients with a bleed, 17.7% died, and the cumulative incidence of death preceded by a bleed was 0.14% after a moderate bleed and 0.24% after a severe bleed (see Figure). Conclusions: Very late ischemic and bleeding events were infrequent, but patients who suffered these events are subject to high mortality risk.