Trends in the distribution of first coronary events in men and women aged 18-74 years in Sweden 1997-2023 – women are becoming more like men

Background Clinical manifestations of coronary heart disease (CHD) increase steeply with age and occur earlier in men than in women. Previous studies of first manifestations of acute coronary syndromes (ACS), defined as a first hospitalization for angina, acute myocardial infarction (AMI), ischemic heart disease (IHD), or death due to CHD have shown that women, compared with men of the same age, initially present with angina, whereas men more commonly present with AMI or CHD death. However, the advent of more sensitive biomarkers about 25 years ago may have caused a shift in the distinction between angina and AMI. Current data on the sex-specific distribution and incidence of different ACS manifestations is limited. Purpose to examine trends in occurrence and distribution of different forms of ACS in men and women aged 18-74 years in Sweden between 1997 and 2023. Methods Nationwide Swedish registers on hospital discharges and cause-specific deaths were used to calculate sex-specific trends for first coronary admissions or deaths in men and women aged 18-74 years during 1997 to 2023. Results A total of 416,572 individuals were identified with a first manifestation of ACS (29% women, 71% men). Marked declines in rates of CHD death, hospitalizations for AMI and for angina were noted in both men and women, with the most conspicuous decline seen for angina (Figure 1). Angina was the most common diagnosis in women during 1997-1999 (47% of all cases, followed, by AMI (36%) and coronary death (15%), with the corresponding proportions for men 35%, 41%, and 22%. By 2021–2023, the distribution had shifted substantially: among women, 19% presented with angina, 63% with AMI, and 12% with CHD death (Figure 2). The corresponding proportions in men were 20%, 61%, and 13%, indicating minimal sex differences in the distribution of first events. Conclusions The incidence of all first manifestations of CHD declined between 1997 and 2023, most notably for angina, likely at least partly reflecting the introduction of more sensitive biomarkers of myocardial injury. Whereas women were more likely than men to present with angina rather than AMI in 1997–1999, and less likely to present with AMI or CHD death, the clinical presentation was largely similar between sexes in 2021–2023. Notably, despite substantial reductions in coronary mortality over time, CHD death remained the first manifestation in 13% of men and 12% of women in 2021–2023.