Abstract 14972: Timing, Profile, and Predictors of Spontaneous Myocardial Infarction Following a Non-ST-Segment Elevation Acute Coronary Syndrome Event: Insights From the TRILOGY-ACS Trial
Background: Patients with ACS are at high risk for recurrent ischemic events, but the frequency with which these events occur and the profiles of patients who experience a spontaneous MI following a medical management strategy for the index ACS event are uncertain.
Methods: We analyzed data from the TRILOGY-ACS trial that evaluated patients with unstable angina/non-ST-elevation MI who were managed medically without planned revascularization. All adjudicated MI events were classified as spontaneous (type 1) or procedure-related (types 4 and 5). We used a multivariate Cox proportional hazards model to determine predictors of spontaneous MI.
Results: From 9326 patients enrolled in TRILOGY, 695 spontaneous MI events were adjudicated, representing 94% of all 737 MI events (32 patients with events that could not be classified as spontaneous vs procedural were excluded). At a median follow-up of 16 months, the Kaplan-Meier event rate of spontaneous MI through 30 months was 11%. Baseline characteristics of patients with and without spontaneous MI are shown (Table). The 3 strongest independent predictors of spontaneous MI were: index event being NSTEMI vs UA (adjusted HR 2.46; 95% CI 1.97-3.03), older age (adjusted HR 1.14; 95% CI 1.10-1.19 per 5-y increase), and coronary angiography performed for index event (adjusted HR 0.60; 95% CI 0.50-0.72).
Conclusion: The event rate of spontaneous MI following a medically managed UA/NSTEMI event exceeds 10% through 30 months of follow-up. Key baseline characteristics strongly predicted subsequent risk of spontaneous MI in this population and may be used to optimize risk stratification of patients at highest risk for this complication. Our findings provide unique insight into the long-term natural history of medically managed UA/NSTEMI patients and may help guide the design of clinical trials evaluating novel ACS therapies.
- © 2013 by American Heart Association, Inc.