Study and Patient Selection
Institutional Review Board review is not required for meta-analyses because only de-identified, publically-available data were used and no human subjects involvement20. We included all studies that: (1) reported permanent LBBP, (2) were in English, (3) included patients ≥18 years old, (4) had a previous diagnosis of HFrEF, (5) with an indication for CRT, (6)compared with BVP. Case reports, abstracts, editorials/letters, reviews, and studies with fewer than 5 patients were excluded. The study contained the most data included if multiple publications were generated from the same patient cohort. Two authors (C Jin and Q Dai) independently extracted data from the selected studies. A third reviewer was consulted (P Li) was consulted in the instance of a disagreement.