Myocardial Infarction Without Obstructive Coronary Disease in Later Life: Insights from the Malmö Diet and Cancer Study.

Background: The prognostic significance of myocardial infarction with non-obstructive coronary arteries (MINOCA) in older adults remains uncertain, particularly in comparison with revascularized acute coronary syndromes (ACS) and other acute myocardial injury phenotypes. Methods: In the prospective population-based cohort of the Malmö Diet and Cancer Study (n = 30,466), 925 participants who experienced an incident coronary event between 2009 and 2018 were classified as revascularized ACS, MINOCA, or other acute myocardial injury phenotypes. All-cause mortality was assessed using Kaplan-Meier estimates and Cox proportional-hazards models. Results: Of 925 patients (mean age, 81 ± 7 years; female sex, 57%), 136 (14.7%) had a non-revascularized event, including 49 (36%) classified as MINOCA and 87 (64%) as other acute myocardial injuries. All non-revascularized cases underwent detailed review of angiographic and clinical records. During a median follow-up of 2.5 years, mortality was substantial across all groups (81%, overall). In unadjusted analyses, survival did not differ significantly among event categories (p = 0.302). In multivariable analysis, MINOCA was associated with increased mortality compared with revascularized ACS (aHR 1.48; 95% CI 1.07-2.05; p = 0.018) and with other acute myocardial injury phenotypes (aHR 1.44; 95% CI 1.01-2.04; p = 0.041). Other acute myocardial injury phenotypes did not differ significantly from revascularized ACS (aHR 1.03; 95% CI 0.78-1.35). Conclusions: MINOCA is associated with higher mortality than both revascularized ACS and other acute myocardial injury phenotypes. Despite the absence of obstructive coronary disease, MINOCA in later life carries an adverse prognosis and commands systematic diagnostic evaluation, careful phenotypic characterization, and appropriate risk-directed management.