Risk of serious cardiac events in older adults using antipsychotic agents.

Background: Antipsychotic agents can lead to severe cardiovascular adverse events due to multiple mechanisms involving electrophysiologic and metabolic effects. Few epidemiologic studies have evaluated the risk of serious cardiovascular-related events in typical and atypical antipsychotic users.

Objective: The purpose of this study was to compare the risk of serious cardiac events in older adults taking typical antipsychotics with those taking atypical antipsychotics.

Methods: Prescription and medical information were derived from the IMS LifeLink Health Plan Claims database. The study involved a retrospective cohort of older adults (≥50 years) taking atypical or typical antipsychotics from July 1, 2000, to December 31, 2007. The primary outcome measure was hospitalization or emergency room visit due to serious cardiac events, including thromboembolism, myocardial infarction, cardiac arrest, and ventricular arrhythmias within 1 year after the index date. The 2 groups were matched on a propensity score to minimize the baseline differences between the groups. Survival analysis was conducted on the matched cohort to assess the risk of serious cardiovascular events in typical versus atypical users.

Results: A total of 5580 patients were selected in each antipsychotic users group after propensity score matching. Serious cardiac events were found in 666 (11.9 %) atypical antipsychotic users and 698 (12.4%) typical antipsychotic users. Survival analysis revealed that typical antipsychotic users were at increased risk of serious cardiovascular events compared with atypical antipsychotic users (hazard ratio = 1.21; 95% CI, 1.04-1.40) after controlling for other factors.

Conclusions: Moderate increases in risk of serious cardiac events are associated with older adults using typical antipsychotic agents compared with atypical users. Health care professionals should carefully evaluate the benefit/risk ratio of antipsychotic agents before prescribing these agents to a vulnerable population.