Evaluating Outcomes of Over-Expanding Versus Conventional Sizing in transcatheter aortic valve replacement for Borderline Aortic Annulus: A Meta-Analysis.

Approximately 20-40% of patients that present for transcatheter aortic valve replacement (TAVR) with a balloon-expandable (BE) transcatheter heart valve (THV) fall into a borderline aortic annulus size (BAAS). There are potential benefits to over-expanding an under-sized THV (OE-THV) in such cases that include reduced electrical disturbances and annular injury at the expense of increased paravalvular leak (PVL). We conducted a meta-analysis of data comparing conventional sized vs OE-THV strategy for BAAS and review the literature for BE-THV in such cases. 9 non-randomized studies that compared a conventional strategy to OE-THV in patients with BAAS were included in our study. Our findings suggest that there is no difference in mortality, stroke, mean gradient or significant PVL. There was a trend towards less pacemakers in patients receiving an OE-THV. Borderline aortic annulus measurements are common in patients undergoing TAVR and there appears to be equipoise between conventional sizing vs OE-THV. Future detailed studies are required to evaluate short- and long-term outcomes amongst strategies.