Abstract P353: Survival after Acute Coronary Syndrome in the Community

Abstract

Background: Contemporary data on survival after incident acute coronary syndrome (ACS), including both myocardial infarction (MI) and unstable angina (UA), are limited. Objective: To describe survival after incident ACS, to determine if it differs by ACS type (MI or UA) and to determine whether it has improved over time. Methods: Olmsted County, MN residents hospitalized between 1/1/2005-12/31/2010 were screened for incident ACS. ACS was defined as either MI validated by standard epidemiological criteria or UA validated by the Braunwald classification. Patients were followed for death from any cause. Cox proportional hazards regression was used to determine whether survival differed by ACS type, while adjusting for year of diagnosis, age, sex and comorbidities. Results: Among 1,160 incident ACS cases (mean±SD age 66.9±14.8, 60% male), 35% were UA and 65% were MI. After a mean (SD) follow up of 3.7 (2.1) years, 274 deaths occurred. The 3-year Kaplan-Meier survival estimate for MI was 79.6% (95% CI: 76.7%-82.6%) and for UA was 84.9% (95% CI: 81.3%-88.6%) (log-rank p=0.011). The association of ACS type with survival differed by age (p=0.056). After adjustment for year of diagnosis, sex and comorbidities, no difference in survival was observed between ACS types among those aged <60 (HR for MI vs. UA: 0.64, 95% 0.29-1.42). By contrast, among patients aged 60-79, those with an MI had 2 times the risk of death compared to those with UA (HR: 2.04, 95% CI: 1.24-3.37). Patients aged 80 or older who had an MI had a 40% increased risk of death compared to patients of the same age who had UA (HR: 1.42, 95% CI: 1.02-1.98). There was no difference in survival over time (HR for 2010 vs. 2005: 0.91, 95% CI: 0.61-1.36). Conclusions: Survival did not differ between UA and MI patients younger than 60, however among patients 60 or older, survival was worse among those with an MI. Survival after ACS did not change over the study period.