Sex differences in myocardial infarction patients with or without reduced ejection fraction
E Hamilton, L D Desta, C R Reitan, T J JernbergAbstract
Abstract
Intro There is a lack of contemporary data describing how the female survival advantage is affected by age and left ventricular systolic dysfunction (LVSD) after acute myocardial infarction (AMI).
Purpose
This study aimed to evaluate the interaction between sex, age, and ejection fraction (EF) regarding long-term all-cause mortality in a nationwide population. We further examined sex-specific differences in baseline comorbidities and secondary prevention strategies over a 17-year period.
Methods
We studied a cohort of 167,174 patients from the SWEDEHEART registry, aged ≥18 years, presenting with a first-time AMI and echocardiographic assessment during hospitalisation. Relative risks were calculated using Cox proportional hazards regression models (Model 1: age-adjusted; Model 2: age + comorbidities; Model 3: age + comorbidities + discharge treatment). Analyses were stratified by age categories and four temporal periods (2005–2022).
Results
Women were older at presentation (median 74 vs. 67 years) and had a higher prevalence of hypertension, diabetes mellitus, and chronic kidney disease. Women were less frequently treated with percutaneous coronary intervention (PCI), P2Y12 inhibitors, and statins at discharge. Among individuals <70 years, age-adjusted mortality was consistently higher in women regardless of EF, whereas the opposite was observed in those aged ≥70 years (Figure 1). The pattern with the highest age-adjusted hazard ratio for women in those <60 years, with decreasing hazard ratios across increasing age groups, has become increasingly evident over time (Figure 2), with similar results when analyses were stratified by EF. Adjusting for comorbidities and discharge treatment did not materially change the models.
Conclusion
Post-AMI prognosis is characterised by a sex-dependent inversion of risk. In young women (<60 years), the traditional survival advantage is reversed, with women facing a higher mortality risk than men. This shift from protection to vulnerability is seen in all EF classes but most pronounced in those with significant LVSD. The interaction between age and sex has increased over the years which warrants more studies.