Usefulness of NT-Pro-BNP and echocardiography in the diagnosis of subclinical clozapine-related cardiotoxicity

Background: Available information regarding clozapine-related cardiomyopathy is limited to reports of severe left ventricular dysfunction not rarely with fatal clinical evolution. A subclinical cardiotoxic effect might be diagnosed using echocardiography and N-terminal pro-B-type natriuretic peptide assay. Methods: Thirty-eight patients with psychotic disorder in chronic therapy with clozapine (24 male and 14 female subjects; mean age, 38.4 years) were enrolled. Left ventricular ejection fraction (LVEF) was measured by area-length method (average of 5 measurements). Results: Twelve patients showed a mild depression of left ventricular function (LVEF between 50% and 55%), 2 LVEF less than 50% and 1 less than 30%. The area under the receiver operating characteristic curve for N-terminal pro-B-type natriuretic peptide as a predictor of left ventricular dysfunction was 0.87. Conclusions: A subclinical left ventricular dysfunction was found in 3 of 38 patients, whereas a mild impairment of the left ventricular systolic function occurred in 1 of 3 of young, previously healthy, clozapine-treated patients A prospective study in clozapine-naive patients may be useful to better understand cardiotoxic effects of clozapine.