Restricted Loss of Life Expectancy in Patients With Acute Myocardial Infarction: A Nationwide KAMIR Registry Study

Abstract

Background The mortality risk of acute myocardial infarction declines rapidly after the initial period, yet the quantitative measures of residual risk in the follow‐up period remain limited. We aimed to assess restricted loss of life expectancy (LOLE) in patients with acute myocardial infarction. Methods We included patients from KAMIR (Korea Acute Myocardial Infarction Registry), a nationwide acute myocardial infarction registry, between 2012 and 2020. The survival of 27 705 patients (mean age, 64 years; 76% men) was compared with an age‐, sex‐, and calendar year–matched reference cohort derived from Korean population life tables. Three‐year restricted LOLE was estimated using a Royston–Parmar flexible parametric survival model adjusted for clinical characteristics. Results Overall, 3‐year restricted LOLE was 23 (95% CI, 22–25) days. In subgroup analyses, older age (≥75 years, 42 [95% CI, 37–47] days versus <50 years, 7 [95% CI, 3–10] days), female sex (44 [95% CI, 37–51] days versus male sex, 14 [95% CI, 11–17] days), and lower left ventricular ejection fraction (≤40%; 135 [95% CI, 128–142] days versus ≥50%, 0 [−2 to 1] days) were associated with higher 3‐year restricted LOLE. Across the study period, 3‐year restricted LOLE nearly halved from 36 (95% CI, 31–41) to 16 (95% CI, 9–23) days. Conclusions Restricted LOLE provides intuitive, patient‐centered measures of residual risk after acute myocardial infarction. It also demonstrated a significant improvements in patient outcomes over the study period.