Abstract 16963: A Nation-Wide Study on Incidence, Mortality and Case Fatality of Acute Coronary Syndrome Reveals Levelling Off of the Incidence Decrease Among Young Women Aged 35-54 Years in 1996-2021 in Finland

Introduction/background: Incidence and case fatality (CF) of acute coronary syndrome (ACS) have declined in the last decades, but cardiovascular disease remains one of the leading causes of death in the Western world. The knowledge of the current trends in incidence, mortality, and CF of ACS from Finland and even worldwide is sparse, though some studies have suggested slowed incidence decrease and even increase in younger age groups. Thus, we set out to investigate the changes in these event rates in Finland from 1996 to 2021.

Research questions/hypothesis: To examine how the ACS burden has evolved in Finland from 1996 to 2021, especially after 2010.

Methods/approach: We used Finnish country-wide registers, i.e., Hospital Discharges Register (HDR, from Care register for health care) and the National Causes of Death Register with complete coverage of non-fatal and fatal ACS events. We analyzed incidence and mortality rates, and CF, as well as the significance of their trends using negative binomial and logistic regression adjusting for age and sex.

Results/data: Altogether, 186 489 non-fatal and 72 907 fatal incidents of ACS events were included in the analysis. ACS incidence decreased in men (Annual percentage change (APC) -2.0% [95% CI -2.2 to -1.8]) and in the older age groups of women (APC of 55-64-year-old -1.5% [-1.7 to -1.2] and

65-74-year-old -3.3% [-3.5 to -3.1]), but the decrease in incidence slowed down over the last decade. Importantly, in 35-54-year-old women ACS incidence decrease halted (APC of 35-44-year-old 0.4% [-0.3 to 1.0] and 45-54-year-old 0.2% [-0.1 to 0.5]). ACS mortality and case-fatality declined steadily in both sexes and all age groups throughout the study period (APC of the mortality in men -4.5% [-4.7 to -4.3] and in women -5.1% [-5.3 to -4.7]. APC of the CF in men -2.7% [-2.9 to -2.6] and in women -3.4% [-3.6 to -3.2]).

Conclusions: In concordance with other recent reports, we showed that the ACS mortality in both men and women was steadily decreasing. However, we observed that ACS incidence decline slowed down in older age groups and even halted in women aged 35-54. These alerting results emphasize the need for cardiovascular prevention, particularly in young and middle-aged women.