Changes of Atrial Natriuretic Peptides after Defibrillation Threshold Testing Predicted Future Ventricular Arrhythmia Event.

BACKGROUND We investigated the change of natriuretic peptides during defibrillation threshold (DFT) testing and its relationship with future ventricular arrhythmia (VA) events in patients implanted with an implantable cardioverter defibrillator (ICD). METHODS Atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and c-type natriuretic peptide (CNP) were measured in 21 patients (mean age 61 ± 13 years; 67% male) undergoing ICD implantation. Blood samples of the patients were drawn at pre-implantation, 30 minutes, 60 minutes, and 24 hours after DFT testing. The patients were followed and divided into two groups according to the occurrence of VA in 18 months. The biomarker levels and their changes were compared in patients with and without further VA. RESULTS The pre-implantation ANP levels were higher at pre-implantation and increased significantly at 30 minutes after DFT testing (Δ30minANP) among patients with VA events. The BNP and CNP levels did not change significantly after DFT testing in both groups. The area under curve was 0.82 for the change in Δ30minANP determining further ventricular events. The optimal Δ30minANP cutoff value was 0.51 pg/ml, with sensitivity of 0.83 and specificity of 0.68. Multivariable analysis confirmed that patients with Δ30minANP more than 0.51 pg/ml have a higher risk of further ventricular events (hazard ratio 39.8, 95% confidence interval: 2.87-553.01, p = 0.006). The pre-implantation ANP level could not predict future VA events (hazard ratio 1.06, 95% CI: 1.00-1.14, p = 0.06). CONCLUSIONS The increase of ANP concentration after DFT testing predicted future VA events after ICD implantation while the BNP and CNP levels did not predict future VA events.