Antipsychotic drug exposure and risk of myocardial infarction

Cardiovascular Events Associated with Antipsychotics in Newly Diagnosed Parkinson's Disease Patients: A Propensity Score Matched Cohort Study

PURPOSE

Observational studies have examined the association between antipsychotics and ischemic heart disease (IHD) in general populations, but results did not take into account other comorbid diseases, such as Parkinson's disease (PD). This study investigates the one-year risk of IHD, all cardiovascular events, and all-cause mortality among newly diagnosed PD patients who used antipsychotics compared to non-users.

MATERIALS AND METHODS

This study included individuals aged 40 years or older with a first definitive PD diagnosis Read Code in the Secure Anonymised Information Linkage (SAIL) databank who had been initiated on any PD medication between 2000 and 2016. Antipsychotic users were matched 1:1 with non-users by a propensity score model to control the confounding effects of patients' demographics, social deprivation status, comorbidities, and medication history. Cox regression was performed to calculate the hazard ratios (HR) and 95% CIs for the association between antipsychotics and study outcomes.

RESULTS

A total of 1837 participants were included in the analysis. Users of first-generation antipsychotics (FGA) were significantly more likely to develop IHD compared to non-users, with an HR of 2.60 (95% CI 1.103-6.167). Among the FGAs, haloperidol had the highest likelihood of IHD developing, with an HR of 3.01 (95% CI 1.038-8.729). Any use of antipsychotics, regardless of whether they were FGA or second-generation antipsychotics (SGA), was linked to all-cause mortality, with an HR of 4.201 (95% CI 3.272-5.394). When subdividing antipsychotics into FGAs and SGAs, mortality was more likely in FGA users, with an HR of 7.557 (95% CI 5.633-10.139). Mortality also occurred in SGA users, but with a lower HR of 3.278 (95% CI 2.509-4.282).

CONCLUSION

FGAs were associated with an increased risk of IHD and all-cause mortality in newly diagnosed PD patients with psychosis. This finding emphasizes the need to use antipsychotics with caution in PD patients with psychosis.

Association between antipsychotic use and acute ischemic heart disease in women but not in men: a retrospective cohort study of over one million primary care patients

BACKGROUND

Research comparing sex differences in the effects of antipsychotic medications on acute ischemic heart disease (IHD) is limited and the findings ambiguous. This study aimed to investigate these associations within a primary care setting.

METHODS

Hong Kong public general outpatient electronic records of patients aged 45+ during 2007-2010 were extracted, with the last consultation date as the baseline for a 4-year follow-up period to observe acute IHD hospitalizations (2011-2014). Antipsychotic use was defined as any prescription over the previous 12 months from a list of 16 antipsychotics, while acute IHD was defined by ICD-9: 410.00-411.89. Both sex-specific and sex-combined (both sexes) mixed-effects Cox models (random intercept across 74 clinics) were implemented to examine the association and test the interaction between antipsychotics and sex.

RESULTS

Among 1,043,236 included patients, 17,780 (1.7%) were prescribed antipsychotics, and 8342 (0.8%) developed IHD. In sex-specific analyses, antipsychotic prescription was associated with a 32% increased hazard rate of acute IHD among women (95% CI 1.05-1.67) but not among men. A likelihood ratio test comparing sex-combined models with and without the interaction between antipsychotic use and sex suggested significant interaction (χ² = 4.72, P = 0.030). The association between antipsychotic use and IHD among women attenuated and became non-significant when haloperidol was omitted from the operationalization of antipsychotic use (HR = 1.23, 95% CI 0.95-1.60).

CONCLUSION

Our results suggest that antipsychotic prescription is moderately associated with an increased risk of acute IHD among women in primary care and this relationship may be explained by specific antipsychotics. Further research should observe and capture the potential intermediary mechanisms and the dose-response relationship of this association to provide more rigorous evidence to establish causality and inform clinical practices.