Abstract 6084: Long-Term Prognostic Impact of ST-elevation vs. Non-ST-elevation Myocardial Infarction
Whether long-term mortality differs substantially for patients with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation MI (NSTEMI) remains controversial. We retrospectively identified patients with STEMI (n=2413) vs. NSTEMI (n=1974) who underwent cardiac catheterization at Duke University Medical Center between 1999 and 2005. Piece-wise analyses compared adjusted mortality rates over restricted time intervals. Landmark analyses evaluated mortality conditional upon 6-month survival. Between 1999 and 2007, 1274 patients died, with a median follow-up of 4 years. Unadjusted mortality rates for the STEMI and NSTEMI groups were 9.5% vs. 14.3% at 1 year and 28.9% vs. 44.9% at 8 years (figure 1⇓). The mortality difference persisted after adjustment for co-morbidities, angiographic disease severity and 30-day revascularization status (hazard ratio [HR] 0.82, 95% confidence interval [CI] 0.72– 0.95, for STEMI vs. NSTEMI). In a 6-month landmark analysis, the mortality difference persisted after adjustment for medication use 6-months after discharge (HR 0.76, 95% CI 0.62– 0.93). Furthermore, the piece-wise analysis showed a higher early adjusted mortality risk for STEMI (HR 1.85, 95% CI 1.45–3.45) and a higher late adjusted mortality risk for NSTEMI (HR 0.68, 95% CI 0.59 – 0.79). Among patients undergoing cardiac catheterization for acute MI, patients with NSTEMI have a greater risk of late mortality compared to patients with STEMI. These data suggest that extended follow-up to understand the true impact of interventions on long-term mortality is critical in clinical trials of NSTEMI.