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

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.

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.

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.

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.