The Relation between Volume and Outcome of Transcatheter and Surgical Aortic Valve Replacement: A Systematic Review and Meta-Analysis

Transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) are standard procedures for dealing with severe aortic stenosis patients. Researchers have not carried out a systematic review of the volume-outcome relationship in TAVR and SAVR. Our study is intended to address this problem. We systemically searched databases through MEDLINE, EMBASE, PUBMED, and the Cochrane Library up to September 2019. Two reviewers independently screened for the studies and evaluated bias. We used short-term mortality (in-hospital or 30-day mortality) as an outcome. A meta-analysis of TAVR with 115,596 patients ranging from 2005 to 2016 showed a result significantly in favor of high-volume hospitals (OR 0.43 (CI 0.36-0.51)). The subgroup of population period, region, data type, and cut-off value did not show any difference. A meta-analysis of SAVR comprising 418,384 patients ranging from 1994 to 2011 revealed that the OR of short-term mortality for a high-volume hospital compared with that of a low-volume hospital was 0.73 (CI 0.71, 0.74). No difference was observed in subgroups based on population period and cut-off. In conclusion, we found that short-term mortality was lower in high-volume hospitals for both TAVR and SAVR.