Case Fatality of Patients with Type 1 Diabetes after Myocardial Infarction
Objective: Type 1 diabetes is a risk factor for myocardial infarction (MI). We aimed to evaluate the case fatality of type 1 diabetes patients after MI.
Research design and methods: Consecutive MI patients with type 1 diabetes (n=1,935; 41% female, mean age: 62.5 years) and without diabetes (n=74,671) admitted to 20 hospitals in Finland from 2005–2018 were studied using national registries. The outcome of interest was death within one year after MI. Differences between groups were balanced by multivariable adjustments and propensity score matching.
Results: Case fatality was higher in type 1 diabetes patients than in propensity score-matched controls without diabetes at 30 days (12.8% versus 8.5%) and at one-year (24.3% versus 16.8%) after MI (hazard ratio: 1.55; 95% confidence interval: 1.32–1.81; p<0.0001). Patients with type 1 diabetes had poorer prognosis in subgroups of males and females, patients with and without ST elevation MI, revascularized and non-revascularized, with and without atrial fibrillation, and with and without heart failure. The relative fatality risk in type 1 diabetes was highest in younger patients. Older age, heart failure, peripheral vascular disease, renal failure and no revascularization were associated with worse prognosis after MI. The case fatality among type 1 diabetes patients decreased during the study period, but outcome differences compared to patients without diabetes remained similar.
Conclusions: Patients with type 1 diabetes are at higher risk of death after MI than patients without diabetes. Our findings call for attention to vigorous cardiovascular disease prevention in type 1 diabetes patients.