Causes of death in patients ≥75 years of age with non-ST-segment elevation acute coronary syndrome.
The causes of death within 1 year of hospital admission in patients with non-ST-segment elevation acute coronary syndromes are ill defined, particularly in patients aged ≥75 years. From January 2008 through May 2010, we enrolled 645 patients aged ≥75 years with non-ST-segment elevation acute coronary syndromes: 313 in a randomized trial comparing an early aggressive versus an initially conservative approach, and 332, excluded from the trial for specific reasons, in a parallel registry. Each death occurring during 1 year of follow-up was adjudicated by an independent committee. The mean age was 82 years in both study cohorts, and 53% were men. By the end of the follow-up period (median 369 days, interquartile range 345 to 391), 120 patients (18.6%) had died. The mortality was significantly greater in the registry (23.8% vs 13.1%, p = 0.001). The deaths were classified as cardiac in 94% of the cases during the index admission and 68% of the cases during the follow-up period. Eighty-six percent of the cardiac deaths were of ischemic origin. In a multivariate logistic regression model that included the variables present on admission in the whole study population, the ejection fraction (hazard ratio 0.95, 95% confidence interval 0.94 to 0.97; p <0.001), hemoglobin level (hazard ratio 0.85, 95% confidence interval 0.76 to 0.94; p = 0.001), older age (hazard ratio 1.05, 95% confidence interval 1.01 to 1.10, p = 0.010), and creatinine clearance (hazard ratio 0.99, 95% confidence interval 0.97 to 0.99; p = 0.030) were the independent predictors of all-cause death at 1 year. In conclusion, within 1 year after admission for non-ST-segment elevation acute coronary syndromes, most deaths in patients aged ≥75 years have a cardiac origin, mostly owing to myocardial ischemia.