ICDS
Right ventricular pacing is an independent predictor for ventricular tachycardia/ventricular fibrillation occurrence and heart failure events in patients with an implantable cardioverter–defibrillator
1 Department of Cardiovascular Medicine, Hannover Medical School, Carl-Neuberg Str. 1, 30625 Hannover, Germany; 2 Department of Thoracic and Cardiovascular Surgery, Hannover Medical School, Carl-Neuberg Str. 1, 30625 Hannover, Germany
Aims: There is increasing evidence that right ventricular (RV) pacing may have detrimental effects by increasing morbidity and mortality for heart failure in implantable cardioverter–defibrillator (ICD) patients. In this study we prospectively tested the hypothesis that cumulative RV pacing increases ventricular tachycardia/ventricular fibrillation (VT/VF) occurrence (primary endpoint) and hospitalization and mortality for heart failure (secondary endpoint) in a predominantly secondary prophylactic ICD patient population.
Methods and results: Two hundred and fifty patients were divided into two groups according to the median of cumulative RV pacing (
2 vs. >2%) and prospectively followed-up for occurrence of primary and secondary endpoints for 18 ± 4 months. Established predictors for VT/VF occurrence and heart failure events such as age, left ventricular ejection fraction (EF), QRS duration, history of atrial fibrillation, and NT-proBNP were collected at enrolment. Multivariate Cox regression analysis revealed that cumulative RV pacing > 2% and EF < 40% were independent predictors for VT/VF occurrence and heart failure events. Kaplan–Meier analysis showed that patients with >2% cumulative RV pacing more frequently suffered from VT/VF occurrence and heart failure hospitalization.
Conclusion: Cumulative RV pacing > 2% and EF < 40% are independent predictors for VT/VF occurrence and mortality and hospitalization for heart failure in predominantly secondary prophylactic ICD patients. Our data show that algorithms capable of reducing cumulative RV pacing should be used more frequently in clinical practice.
Key Words: ICD, Heart failure, Right ventricular pacing, VT/VF
* Corresponding author. Tel: +49 511 5323817; fax: +49 511 5328475. E-mail address: gunnarklein{at}yahoo.de
Both authors contributed equally to the study.
Manuscript submitted 25 October 2007. Accepted after revision 12 January 2008.