Biventricular vs. right ventricular pacing devices in patients anticipated to require frequent ventricular pacing (BioPace)

Aims Right ventricular (RV) pacing may promote left ventricular (LV) dysfunction. Particularly in patients with preserved LV ejection fraction (LVEF), narrow QRS, and anticipated high ventricular pacing burden (HVPB), evidence is missing that biventricular (BiV) pacing can improve clinical outcome. We therefore evaluated whether implantation of a BiV pacing device (BiVPD) compared with a RV pacing device (RVPD) may improve clinical outcome in predominantly this kind of patients.Methods and results In the Biventricular Pacing for atrioventricular Block to Prevent Cardiac Desynchronization (BioPace) trial [multicentre, single-blinded (patients), randomized, parallel group], patients were equally allocated to either receive a BiVPD or a RVPD. Co-primary endpoints were (i) the composite of time to death or first heart failure hospitalization and (ii) survival time. We analysed 1810 randomized patients (median age: 73.5 years; female sex: 31.7%; mean LVEF 55.4%; mean QRS 118.4 ms), 902 to BiV and 908 to RV pacing. During mean follow-up of 68.8 months, the difference in the primary composite endpoint between both groups [346 vs. 363 events, hazard ratio (HR) 0.878; 95% confidence interval (CI) 0.756-1.020; P = 0.0882) or in mortality (305 vs. 307 deaths, HR 0.926; 95% CI 0.789-1.088; P = 0.3492) was smaller than 20%.Conclusion In patients, predominantly with preserved LVEF, narrow QRS, and HVPB, superiority of implanting BiVPDs compared with RVPDs could not be proven. Right ventricular pacing may be less harmful for this kind of patients than often suggested and primary BiV pacing does not clearly improve their clinical outcome.Clinical trial registration Registered in ClinicalTrials.gov, number NCT00187278 (https://clinicaltrials.gov/ct2/show/study/NCT00187278).