Search strategy
This meta-analysis was conducted in compliance with the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA), and we have registered this work online at its inception on PROSPERO to minimize duplicate efforts.
We searched the Embase, PubMed and Cochrane CENTRAL from the inception dates to May 2020, using the key words: (((heart failure) or (Cardiac Failure) or (Heart Decompensation)) and ((Cardiac resynchronization therapy) or (CRT)) AND ((Defibrillator) OR (Defibrillation) OR (CRT-D))). There was no language restrictions and the literatures were searched by one researcher. We also checked the bibliographies of potentially relevant studies and reviews for additional studies.