Abstract 2215: Bleeding and Outcome in Acute Coronary Syndrome: Insights from Continuous ECG Monitoring in the INTERACT Trial
Background: Bleeding is associated with adverse outcome in acute coronary syndromes (ACS). However, the precise pathophysiologic mechanisms have not been elucidated.
Objective: To determine the relationship between bleeding and myocardial ischemia detected by concurrent continuous ECG monitoring, and their long-term prognostic impact.
Methods: The INTERACT trial was a randomized controlled trial of enoxaparin versus unfractionated heparin in patients with non-ST elevation ACS, who received concomitant aspirin and eptifibatide. ST-segment monitoring (performed after enrollment up to 96h) was analyzed by an automated algorithm and reviewed by a blinded cardiologist. Major bleeding (within 96h) was defined as fatal bleeding, retroperitoneal hemorrhage, or bleeding with a drop in hemoglobin >30g/L. Bleeding and clinical events were centrally adjudicated in a blinded fashion. We calculated the GRACE risk score (which includes age and creatinine), a validated predictor of mortality, for each patient. The present analysis included 598 patients who survived the first 96h with analyzable data on continuous ECG monitoring and GRACE risk score.
Results: The median GRACE risk score was 115 (IQR 96 to 135); major bleeding and ST-segment shifts occurred concurrently in 22 (3.7%) and 161 (26.7%) patients, respectively. Bleeding was more frequently associated with the presence of ST-segment shifts (P<0.05). After a median follow-up of 2.4 years, patients with major bleeding had a higher risk of death (26.9% vs 6.3%, log-rank P<0.001) and death/MI (36.8% vs 12.0%, log-rank P<0.001) compared to those without.
Conclusions: Bleeding is a powerful independent predictor of poor long-term outcome, even after adjusting for other associated prognostic factors such as advanced age and renal dysfunction. Furthermore, the adverse prognostic impact of bleeding may be mediated by complex pathophysiologic mechanisms rather than myocardial ischemia alone.