Increased long-term mortality after myocardial infarction in patients with schizophrenia

BACKGROUND: Ischemic heart disease increases mortality in patients with schizophrenia. This nationwide study explored short-term and long-term mortality rates in patients with schizophrenia experiencing myocardial infarction (MI) compared to controls from the general population experiencing MI, as well as patients with schizophrenia and people from the general population not experiencing MI.

METHOD: A Danish nationwide cohort study including incident patients diagnosed with schizophrenia between 1980 and 2015, matched 1:5 on year of birth and gender to controls from the general population. Primary outcome was all-cause mortality. Data were analysed utilizing Cox regression models, Kaplan-Meier estimates and standardized mortality ratios (SMR).

RESULTS: Patients with schizophrenia experiencing MI had an increased mortality rate (Hazard rate ratio (HR) 9.94, 95%CI(8.71-11.35)), as well as schizophrenia controls (HR 4.50, 95%CI(4.36-4.64)) and MI controls (HR 3.27, 95%CI(3.03-3.52)) with controls not experiencing MI serving as reference in a model adjusted for age at entry, gender and calendar year. No difference in 30-day mortality was observed between groups experiencing MI, but increased mortality rates were shown in patients with schizophrenia at 1-year and 5-year follow-up. Trends in SMR declined in MI controls, while patients with schizophrenia showed an unchanged SMR over time.

CONCLUSIONS: Patients with schizophrenia have not experienced a decline in mortality rate following MI compared to the general population in long-term follow-up. This finding highlights the need for research in MI follow-up care for patients with schizophrenia.