Gender differences in the decrease of in-hospital mortality in patients with acute myocardial infarction during the last 20 years in Switzerland

Objective To assess temporal trends of in-hospital mortality in patients with acute myocardial infarction (AMI) enrolled in the Swiss nationwide registry (AMIS Plus) over the last 20 years with regard to gender, age and in-hospital treatment. Methods All patients with AMI from 1997 to 2016 were stratified according to ST-segment elevation myocardial infarction (STEMI) or non-STEMI (NSTEMI), and gender using logistic regression analyses. Results Among 51 725 patients, 30 398 (59%) had STEMI and 21 327 (41%) had NSTEMI; 73% were men (63.9±12.8 years) and 27% were women (71.7±12.5 years). Over 20 years, crude in-hospital STEMI mortality decreased from 9.8% to 5.5% in men and from 18.3% to 6.9% in women. In patients with NSTEMI, it decreased from 7.1% to 2.1% in men and from 11.0% to 3.6% in women. After adjustment for age, mortality decreased per additional admission year by 3% in men with STEMI (OR 0.97, 95% CI 0.96 to 0.98, P<0.001), by 5% in women with STEMI (OR 0.95, 95% CI 0.93 to 0.96, P<0.001), by 6% in men with NSTEMI (OR 0.94, 95% CI 0.93 to 0.96, P<0.001) and by 5% in women with NSTEMI (OR 0.95, 95% CI 0.93 to 0.97, P<0.001). In patients <60 years, a decrease in mortality was seen in women with STEMI (OR 0.94, 95% CI 0.90 to 0.99, P=0.025) and NSTEMI (OR 0.87, 95% CI 0.80 to 0.94, P<0.001) but not in men with STEMI (OR 1.01, 95% CI 0.98 to 1.04, P=0.46) and NSTEMI (OR 0.98, 95% CI 0.94 to 1.03, P=0.41). The mortality decrease in patients with AMI was closely associated with the increase in reperfusion therapy. Conclusion From 1997 to 2016, in-hospital mortality of patients with AMI in Switzerland has halved and was more pronounced in women, particularly in the age category <60 years. Trial registration number NCT01305785; Results.