Comparison of long-term mortality across the spectrum of acute coronary syndromes

Background: Data are sparse regarding comparative long-term mortality across the spectrum of patients presenting with acute coronary syndrome (ACS). Methods: We identified all patients hospitalized with suspected myocardial ischemia in an urban academic hospital from 1991 to 1992. We compared presenting characteristics, treatment, and long-term mortality between patients with unstable angina (UA), minor myocardial damage (MMD), definite non-ST-elevation myocardial infarction (NSTEMI), and STEMI. Results: Of 760 patients (mean age 68 years, 35% women), 22% had UA, 35% had MMD, 26% had NSTEMI, and 17% had STEMI. During a mean follow-up of 9.5 years, unadjusted mortality was highest in patients with MMD and NSTEMI (mortality for UA 43%, MMD 68%, NSTEMI 62%, STEMI 44%; P < .001). Patients with MMD and NSTEMI were older than patients with STEMI or UA, had more comorbid conditions (diabetes, prior myocardial infarction, congestive heart failure), and were less likely to receive aspirin, unfractionated heparin, or revascularization therapies during the index hospitalization. After multivariable adjustment for all significant covariates, mortality increased sequentially along the spectrum of ACS (hazards ratios for UA 1.0 [referent], MMD 1.12 [95% CI 0.84-1.49], NSTEMI 1.28 [0.95-1.72], and STEMI 1.52 [1.06-2.19]). Conclusions: Patients presenting with MMD and definite NSTEMI had a worse unadjusted long-term prognosis up to 10 years after index hospitalization than patients with STEMI. This mortality excess for MMD/NSTEMI was associated with more comorbid conditions and decreased use of basic therapies for ACS. After controlling for baseline differences, STEMI patients had the highest mortality.