[Usefulness of brain natriuretic peptide to evaluate patients with heart failure treated with cardiac resynchronization].

INTRODUCTION AND OBJECTIVES The aim of the present study was to document the evolution of the blood levels of brain natriuretic peptide (BNP) in patients with heart failure and their correlation with the clinical course after implantation of a biventricular pacemaker. PATIENTS AND METHOD Twenty-eight patients with heart failure associated to left bundle branch block and left ventricular systolic dysfunction were included in the study. In each patient we performed laboratory tests, chest X-ray, electrocardiogram and echocardiogram, and measured blood levels of BNP. RESULTS During follow-up (10 [6] months) functional capacity improved, decreasing from 3.3 (0.6) to 2.10 (0.4) (P=.03). The rate of hospitalizations for heart failure decreased from an average of 1.8 (0.7) (6 months before the procedure) to 0.8 (0.3) (6 months after the procedure; P=.04). The basal value of BNP decreased from 193 (98) pg/mL to 52 (14) at the end of the follow-up in the responder group (22 patients) and increased from 564 (380) to 650 (80) pg/mL in the nonresponder group (6 patients). Patients who responded showed significant clinical improvement and decreasing levels of BNP, which reached a plateau an average of 6 months after implantation. Multivariate logistic regression analysis identified lower levels of BNP, idiopathic dilated cardiomyopathy, and functional class as independent predictors of response to therapy. Age, QRS width and left ventricular ejection fraction were not predictors of response. CONCLUSIONS Brain natriuretic peptide concentrations allowed us to monitor, in an objective manner, the clinical course of patients with biventricular resynchronization therapy.