Slotwiner DJ, Raitt MH, Del-Carpio Munoz F, et al. - Among patients without severe left ventricular dysfunction (> 35%) who needed permanent pacing due to heart block, researchers assessed if cardiac biventricular pacing (BiVP) and/or His bundle pacing (HisBP) might avert adverse remodeling and be connected to structural, functional, and clinical benefits vs right ventricular pacing (RVP). Relevant randomized trials and observational studies were identified from MEDLINE and Embase. They included data from eight studies, comprising 679 patients satisfying the prespecified criteria for inclusion. Findings were compared for BiVP vs RVP, HisBP vs RVP, and BiVP+HisBP vs RVP. Compared with RVP, either BiVP or HisBP resulted in the preservation or increase of the left ventricular ejection fraction (LVEF) among patients with LVEF > 35%. However, the improvement seen in patient-centered clinical outcome seemed to be restricted mostly to those with chronic atrial fibrillation with rapid ventricular response rates and had undergone atrioventricular node ablation.