Is a Goal of 100% Biventricular Pacing Necessary?
Objectives: The goal of this analysis was to determine the appropriate biventricular pacing target in patients with heart failure (HF). Background: Cardiac resynchronization therapy (CRT) decreases the risk of death and HF hospitalization. However, the appropriate amount of biventricular pacing is ill-defined. Methods: Mortality and HF hospitalization data from patients undergoing CRT in 2 trials (CRT RENEWAL [Cardiac Resynchronization Therapy Registry Evaluating Patient Response with RENEWAL Family Devices] and REFLEx [ENDOTAK RELIANCE G Evaluation of Handling and Electrical Performance Study]; n = 1,812) were analyzed in a post-hoc fashion. Subjects were grouped based on percent biventricular pacing quartiles with the use of Kaplan-Meier survival analysis. Results: Subjects were age 72 ± 11 years; 72% were men and 67% had coronary artery disease. Subjects paced 93% to 100% (quartiles 2 to 4) had a 44% reduction in hazard of an event compared with subjects paced 0% to 92% (quartile 1;
