Sex differences in myocardial infarction care and outcomes: a longitudinal Scottish National Data-Linkage Study

We investigate sex disparities in management and outcomes of myocardial infarction (MI) in contemporary practice in Scotland.

This was a longitudinal cohort study including all MI admissions aged 45-80 years across Scotland between 2010-2016 and 2:1 age, sex, and general practice-matched general population controls. Participants were followed up until the end of 2021. We analysed in-hospital outcomes (percutaneous coronary intervention, secondary prevention and mortality) using Poisson regressions, adjusting for age, comorbidities, and ST-elevation. We used Royston-Parmar models for long-term outcomes (all-cause and cardiovascular mortality, incident cardiovascular events), adjusting for age, comorbidities, and secondary prevention. Of a total 47 063 MI patients, 15 776 (33.5%) were women. Median (inter-quartile range) age was 66 (57, 73) years. Compared to men, women were older and more comorbid, but were less likely to undergo percutaneous coronary intervention [risk ratio (95% confidence interval) - 0.87 (0.86 - 0.89)] or receive secondary prevention at discharge [0.94 (0.93-0.95)]. No in-hospital mortality difference was observed between sexes [1.06 (0.99-1.13) after adjustment]. Over a median follow-up of 8.2 (6.7, 10.1) years, women had higher crude rates of adverse outcomes. After full adjustment, this translated into a lower risk for women compared to men of all-cause mortality [hazard ratio, 0.92 (0.89-0.95)], cardiovascular mortality [0.82 (0.78-0.87)], and cardiovascular events [0.92 (0.88-0.95)]. The female survival advantage seen in general population controls was attenuated in MI patients.

Women were undertreated compared to men after MI. Their survival and outcome benefits may be improved further. Poor outcomes in men despite better receipt of secondary prevention require further attention.