Receipt of Cardiac Care Following Hospitalization for an Acute Myocardial Infarction for Individuals With a History of Depression or Schizophrenia

Abstract

Background: The goal of this study was to improve upon methodological limitations of previous studies to determine the existence and source of differences in the cardiac care of individuals with a history of depression or schizophrenia. The selected outcomes were three cardiac procedures: catheterization, percutaneous transluminal coronary angiography (PTCA), and coronary artery bypass graft (CABG); and three cardiac pharmaceuticals: beta-blockers, angiotensin converting enzyme (ACE) inhibitors and statins. Methods: This population-based retrospective cohort study consisted of 309, 790 individuals diagnosed with an AMI and admitted to an acute care hospital in Ontario between April 1, 1995 and March 31, 2009. The time-to-intervention for the depression and schizophrenia was estimated and compared to those without a mental disorder using Cox Proportional Hazards regression. Subgroup analyses were performed to evaluate the interaction between well-established confounders and the receipt of a cardiac intervention. Results: Persons with a history of depression were found to be more likely to receive a catheterization (HR=1.42, 95% CI=1.34-1.50) or PTCA (HR=1.48, 95% CI=1.40-1.57) if they had no previous CVD history, but were less likely to receive a catheterization (HR=0.71, 95% CI=0.51-0.99) or PTCA (HR=0.64, 95% CI=0.39-1.06) if they had a CVD history. In addition individuals with depression were less likely to receive a CABG, especially if they had a history of CVD (HR=0.38, 95% CI=0.24-0.60). Persons with a history of schizophrenia were found to be just as likely to receive a catheterization (HR=0.90, 95% CI=0.70-1.15) or a PTCA (HR=0.83, 95% CI=0.62-1.11). The likelihood of receiving a beta-blocker or statin was comparable or higher for persons with a history of depression (HR=1.07, 95% CI=1.03-1.11; 1.27, 95% ii i CI=1.22-1.32, respectively) and comparable for persons with a history of schizophrenia (HR=0.90, 95% CI=0.79-1.02; HR=0.97, 95% CI=0.83-1.14, respectively), with a small but significant prior drug use effect modification. Interpretation: Persons with depression or schizophrenia with no CVD history are just as likely to receive most recommended cardiac care interventions compared to those without a mental disorder. The source of the differences in care for individuals with a CVD history with depression and schizophrenia needs to be further explored.