Brain natriuretic peptide levels and response to cardiac resynchronization therapy in heart failure patients.

The authors used brain natriuretic peptide (BNP) as a reliable marker to identify nonresponders to cardiac resynchronization therapy (CRT) in patients with advanced heart failure. The study included 70 patients with left ventricular dysfunction (mean ejection fraction, 21+/-4%) and left bundle branch block (QRS duration, 164+/-25 milliseconds) treated with CRT. The authors reviewed data on New York Heart Association functional class, baseline ejection fraction, sodium, creatinine, QRS duration, and BNP levels 3 months before and after CRT therapy. The authors compared results of 42 patients who survived (973+/-192 days) after CRT implantation (responders) to those of 28 patients (nonresponders) who either expired (n=21) or underwent heart transplantation (n=5) or left ventricular assist device implantation (n=2) after an average of 371+/-220 days. Mean BNP levels after 3 months of CRT decreased in responders from 758+/-611 pg/mL to 479+/-451 pg/mL (P=.044), while in nonresponders there was increase in BNP levels from 1191+/-466 pg/mL to 1611+/-1583; P=.046. A rise in BNP levels was associated with poor response (death or need for transplantation or left ventricular assist device and impaired long-term outcome), which makes it a good predictor to identify such patients.