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

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

Methods And Results: 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.

Conclusion: 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.