Impairment of the cardiac ejection fraction by blocking dopamine D2 receptors induced by long-acting injectable antipsychotic treatment

INTRODUCTION: Atypical antipsychotics have numerous benefits compared to conventional ones in respect to the possible adverse effects. However, like the other ones, they may induce direct cardiovascular alterations, probably through the apoptotic effect of dopamine receptor D2 (DRD2) blockade. The main objective of the study was to assess the cardiac ejection fraction (EF) using transthoracic speckle tracking echocardiography (TSTE) in patients treated with long-acting injectable (LAI) atypical antipsychotics. PATIENTS, MATERIALS AND METHODS: This cross-sectional study was conducted on 123 patients with schizophrenia or schizoaffective disorder divided in four samples according to their treatment: Aripiprazole, Olanzapine, Paliperidone and Risperidone. We analyzed socio-demographic data, the intensity of psychiatric symptoms, the duration of psychosis and of LAI treatment, and the cardiac EF measured with TSTE. RESULTS: We found no statistically significant differences between the four antipsychotics regarding the values of the EF. Nevertheless, we observed a trend indicating that patients treated with an antipsychotic associated with a lower affinity for the DRD2, such as Olanzapine, have higher EF values than patients treated with antipsychotics with a stronger binding to the DRD2, such as Paliperidone and Risperidone. Patients receiving Aripiprazole, which has the strongest affinity for the DRD2 from all four antipsychotics but is also a partial DRD2 agonist, display higher EF values than those on Paliperidone and Risperidone. CONCLUSIONS: Antipsychotics with a lower affinity for the DRD2 or a partial agonism for it may be associated with higher EF. Cardiac monitoring should be performed periodically in patients on LAI antipsychotic therapy.