Association of secondary preventive cardiovascular treatment after myocardial infarction with mortality among patients with schizophrenia

Importance: Cardioprotective medication use is an important secondary preventive treatment after cardiovascular events. Patients with schizophrenia have excess cardiovascular morbidity and mortality, but no studies have investigated whether taking recommended cardioprotective medication can reduce this excess mortality. Objective: To assess the association of exposure to secondary cardiovascular treatment with all-cause mortality after myocardial infarction among patients with schizophrenia compared with the general population. Design, Setting, and Participants: This nationwide cohort study included individuals admitted with first-Time myocardial infarction in Denmark from January 1, 1995, to December 31, 2015. The cohort was dichotomously divided by a diagnosis of schizophrenia. Data on the prescription of guideline-recommended cardioprotective medication, including antithrombotics, β-blockers, Vitamin K antagonist, angiotensin-converting enzyme inhibitors, and statins, were obtained from the nationwide registries. Exposures: Time exposed to cardioprotective medication. Main Outcomes and Measure: Cox proportional hazards regression was used to calculate hazard ratios (HRs) with 95% CIs for the association between treatment exposure and all-cause mortality after myocardial infarction between patients with and without schizophrenia. Results: The cohort included 105018 patients with myocardial infarction, including 684 patients with schizophrenia (0.7%; 483 male [70.6%]; mean [SD] age at diagnosis, 57.3 [10.6] years) and 104 334 general population patients (99.3%; 73 454 male [70.4%]; mean [SD] age at diagnosis, 61.0 [10.6] years), with a total follow-up of 796435 person-years and 28059 deaths. Patients diagnosed with schizophrenia who did not receive cardioprotective treatment had the highest mortality rate (HR, 8.78; 95% CI, 4.37-17.64) compared with the general population treated, with treated patients diagnosed with schizophrenia having an increased HR of 1.97 (95% CI, 1.25-3.10). The analyses of the associations of different cardiac therapy strategies with mortality rates revealed that patients with schizophrenia who were treated with any combination of triple therapy had mortality rates similar to those observed in the general population (HR, 1.05; 95% CI, 0.43-2.52) in the multivariable analysis. Conclusions and Relevance: Cardioprotective medication after myocardial infarction should be carefully managed to improve prognosis. The study results suggest that some of the increased cardiac mortality among patients with schizophrenia can be reduced if these patients are efficiently administered combinations of secondary preventive treatments after cardiac events.