Increased risk of acute myocardial infarction after acute episode of schizophrenia: 6 year follow-up study

Objective: The aim of the present study was to estimate the risk of acute myocardial infarction (AMI) among patients who received a first hospital diagnosis of schizophrenia during a 6 year follow-up period. Method: Data from the Taiwan National Health Insurance Research Database were used. The study cohort consisted of 7353 patients who were hospitalized with a principal diagnosis of schizophrenia in 2000. The comparison cohort were 22 059 enrollees randomly selected matched with the study group in terms of gender and age. Each patient was tracked from their index hospitalization in 2000 until the end of 2006 to identify whether or not an AMI had occurred during the follow-up period. Cox proportional hazard regressions were performed to compute the adjusted 6 year survival rate, following adjustment for possible confounding variables. Results: A total of 130 patients suffered AMI during the 6 year follow-up period, including 30 from the study cohort (0.41% of the schizophrenia patients), and 100 (0.45%) from the comparison cohort. But after censoring those patients who died from non-AMI causes and adjusting for potential confounding factors, the risk of AMI occurrence during the 6 year follow-up period was 1.83-fold greater for schizophrenia patients (95% confidence interval 5 1.62-2.05) than for patients in the comparison cohort. Conclusion: Schizophrenia patients had a higher risk of AMI compared to patients in the comparison cohort. The present study draws attention to the need for clinicians to more actively monitor and treat schizophrenia patients with well-recognized risk factors associated with AMI.