Usefulness of brain natriuretic peptide level at implant in predicting mortality in patients with advanced but stable heart failure receiving cardiac resynchronization therapy

Abstract

Background: Brain natriuretic peptide (BNP) level has emerged as a predictor of death and hospital readmission in patients with heart failure (HF). The value of baseline BNP assessment in advanced HF patients receiving cardiac resynchronization defibrillator therapy (CRT-D) has not been firmly established.

Hypothesis: We hypothesized that a baseline BNP level would predict all cause mortality and HF hospitalization in HF patients receiving cardiac resynchronization therapy.

Methods: A retrospective chart review of all patients having BNP assessment prior to implantation of a CRT-D for standard indications during 2004 and 2005 was conducted at the Veterans Affairs Pittsburgh Healthcare System. The primary endpoint was all-cause mortality and the secondary endpoint was HF-related hospitalization. We used findings from the receiver operating characteristic (ROC) curve to define low (<492 pg/mL) and high (> or =492 pg/mL) BNP groups.

Results: Out of 173 CRT-D recipients, 115 patients (mean age 67.0 +/- 10.7 years, New York Heart Association [NYHA] class 2.9 +/- 0.3, left ventricular ejection fraction [LVEF] 22.5% +/- 9.6%, QRS 148.3 +/- 30.4 ms) had preimplantation BNP measured (mean 559 +/- 761 pg/mL and median 315 pg/mL). During a mean follow-up time of 17.5 +/- 6.5 mo, 27 deaths (23.5%) and 31 HF hospitalizations (27.0%) were recorded. Compared to those with low BNP (n = 74), those of high BNP (n = 41) were older, had lower LVEF, higher creatinine levels, suffered more deaths, and HF hospitalizations. In multivariate regression models, higher BNP remained a significant predictor of both the primary endpoint (hazard ratio [HR]: 2.89, 95% confidence interval [CI] 1.06-7.88, p = 0.038) and secondary endpoint (HR: 4.23, 95% CI: 1.68-10.60, p = 0.002).

Conclusions: Baseline BNP independently predicted mortality and HF hospitalization in a predominantly older white male population of advanced HF patients receiving CRT-D. Elevated BNP levels may identify a vulnerable HF population with a particularly poor prognosis despite CRT-D.