Impact of changes of treatments on outcomes in ST-elevation myocardial infarction (STEMI) patients in real-life health care has not been documented.

All STEMI cases (n = 105.674) registered in the nation-wide SWEDEHEART registry between 1995 and 2014 were included and followed for fatal and non-fatal outcomes for up to 20 years. Most changes in treatment and outcomes occurred from 1994 to 2008. Evidence-based treatments increased: reperfusion from 66.2 to 81.7%; primary percutaneous coronary intervention: 4.5 to 78.0%; dual antiplatelet therapy from 0 to 89.6%; statin: 14.1 to 93.6%; beta-blocker: 78.2 to 91.0%, and angiotensin-converting-enzyme/angiotensin-2-receptor inhibitors: 40.8 to 85.2% (P-value for-trend <0.001 for all). One-year mortality decreased from 22.1 to 14.1%. Standardized incidence ratio compared with the general population decreased from 5.54 to 3.74 (P < 0.001). Cardiovascular (CV) death decreased from 20.1 to 11.1%, myocardial infarction (MI) from 11.5 to 5.8%; stroke from 2.9 to 2.1%; heart failure from 7.1 to 6.2%. After standardization for differences in demography and baseline characteristics, the change of 1-year CV-death or MI corresponded to a linear trend of 0.915 (95% confidence interval: 0.906–0.923) per 2-year period which no longer was significant, 0.997 (0.984–1.009), after adjustment for changes in treatment. The changes in treatment and outcomes were most pronounced from 1994 to 2008.

Gradual implementation of new and established evidence-based treatments in STEMI patients during the last 20 years has been associated with prolonged survival and lower risk of recurrent ischaemic events, although a plateauing is seen since around 2008.