Increased N-terminal-pro-B-type natriuretic peptide levels in patients with appropriate implantable defibrillator therapies.

BACKGROUND: The ability to better identify predictors of implantable defibrillator therapies in patients with heart failure would allow the optimization of patient selection. N-terminal-Pro-B-type natriuretic peptide (NT-ProBNP) is secreted by the ventricles in response to myocardial stretching and is a sensitive marker of left ventricular dysfunction and cardiac mortality in patients with heart failure. We assessed the relationship between NT-ProBNP and defibrillator therapies for primary or secondary prevention of arrhythmic death.

METHODS: NT-ProBNP levels were analyzed in 45 patients with stable heart failure symptoms and defibrillator devices, with and without device therapies, and appropriate and inappropriate therapies. Univariate and multivariate analyses were used to identify predictors of appropriate defibrillator therapies.

RESULTS: Device interventions occurred in 21 patients: 12 appropriate therapies and 9 inappropriate therapies. Patients with appropriate therapies had higher NT-ProBNP levels than patients with no device therapies (2469.1 +/- 2281.8 pg/mL vs 838.7 +/- 832 pg/mL; P = .0019), inappropriate therapies (730.4 +/- 503 pg/mL; P = .0046), and combined inappropriate plus no therapies (2469.1 +/- 2281.8 pg/mL vs 713.9 +/- 510.6 pg/mL; P = .0008). The NT-ProBNP level was the only independent predictor of appropriate device therapies during the observation period (P = .004).

CONCLUSION: Elevated NT-ProBNP was an independent predictor of appropriate defibrillator therapies. Extensive myocardial remodeling may create the electrophysiologic conditions necessary to elicit ventricular tachyarrhythmias. Further research is necessary to clarify whether the identification of a subgroup of higher risk may benefit from a more aggressive defibrillator programming.