Comparison of N-Terminal Pro-Brain Natriuretic Peptide Versus Electrophysiologic Study for Predicting Future Outcomes in Patients With an Implantable Cardioverter Defibrillator After Myocardial Infarction

Abstract

The aim of the study was to examine the predictive value of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) versus electrophysiologic study in patients with implantable cardioverter-defibrillators (ICDs) after myocardial infarction (MI). We prospectively studied 99 consecutive patients with a history of MI who underwent ICD implantation for primary or secondary prevention of sudden cardiac death. An electrophysiologic study was performed in all patients. Venous blood samples for NT-pro-BNP measurement were obtained at the beginning of the study. The primary end point was ventricular tachycardia or ventricular fibrillation (VT/VF) and the secondary end point was a composite of death, hospitalization for heart failure, or MI. On multivariate Cox regression analysis, NT-pro-BNP level at or greater than median (497 ng/L) was the only significant predictor for VT/VF occurrence (p = 0.047). Along with amiodarone use (p = 0.001), NT-pro-BNP levels higher than median were also associated with a higher risk of composite clinical events (p = 0.036). Kaplan-Meier analysis showed that patients with NT-pro-BNP level at or greater than median had a higher risk of experiencing VT/VF and composite clinical events than patients with NT-pro-BNP levels less than median (log-rank p <0.05). In conclusion, assay of NT-pro-BNP, which is easy to perform and widely available, is superior to electrophysiologic study for prediction of future outcomes in predominantly secondary prophylactic ICD recipients after MI. In the era of primary prophylactic ICD implantation without preimplantation electrophysiologic study, higher NT-pro-BNP levels might help to improve risk-adjusted concomitant antiarrhythmic therapy and device selection.