Dramatic improvements in survival in women and men with acute myocardial infarction over 30 years: a nationwide cohort study

Abstract

Abstract Background Treatment of myocardial infarction (MI) has improved over the last decades due to the implementation of early revascularization and medical therapies for secondary prevention. The impact of these treatment changes on survival in women and men has not been documented over a 30-year perspective. Purpose The aim of this study was to assess implementation of new treatment strategies and their effects on changes in long-term outcomes in all patients with MI in Sweden over 30 years. Methods In SWEDEHEART, the Swedish register for coronary heart disease, we investigated treatments and outcomes and their associations in patients admitted with MI between 1991-2021. Patients were stratified in 2-year blocks, starting with a 3-year block for 1991-1993. Primary outcome was 1-year risk of cardiovascular (CV) mortality. Effect of treatments on outcome was assessed comparing observed event rates with event rates standardized by logistic regression accounting for differences in baseline characteristics and treatment. Results A total of 433,524 cases with MI were hospitalized between 1991-2021. Between 1991-1993 and 2020-2021, treatment with reperfusion and revascularization increased from 34.7% to 77.3%; in-hospital PCI from 1.8% to 73.8 %; dual antiplatelet therapy (DAPT) from 0.0% to 73.8%; statins from 3.0% to 91.7%; beta-blockers from 66.4% to 88.3%; and renin-angiotensin-system (RAS) inhibitors from 21.6% to 81.6% (Figure 1A). During the same period, the rates of 1-year CV mortality decreased from 24.1% to 8.3%. For women, CV mortality decreased from 28.9% to 10.3% and for men from 21.7% to 7.3%. When comparing observed with standardized event rates, most of the mortality improvement was explained by the implementation of early revascularization with PCI (Figure 1B). Conclusions In this unique nationwide cohort of patients with MI over 30 years, there was a gradual implementation of revascularization and novel medical treatment. Concurrently, there was a gradual absolute reduction in 1-year risk of CV mortality with 16 percentage points, which was similar in women and men. Most of the improvement in survival was related to implementation of early revascularization strategies. Figure 1 (A) Temporal trends in treatment and (B) crude and standardized rates of cardiovascular mortality within 1 year in patients with myocardial infarction over 30 years in Sweden.