Abstract
Background In the absence of randomized controlled trials, reports from nonrandomized studies comparing valve-in-valve implantation (ViV) to redo surgical aortic valve replacement (rAVR) have shown inconsistent results. Methods and Results PubMed/MEDLINE, Google Scholar, and CENTRAL (Cochrane Central Register of Controlled Trials) were searched through December 2021. Meta-Analysis of Observational Studies in Epidemiology guidelines were followed. The protocol was registered at the International Prospective Register of Systematic Reviews. Random effects models were applied. The primary outcomes of interest were short-term and midterm mortality. Secondary outcomes included stroke, myocardial infarction, acute renal failure, and permanent pacemaker implantation, as well as prosthetic aortic valve regurgitation, mean transvalvular gradient, and severe prosthesis-patient mismatch. Of 8881 patients included in 15 studies, 4458 (50.2%) underwent ViV and 4423 (49.8%) rAVR. Short-term mortality was 2.8% in patients undergoing ViV compared with 5.0% in patients undergoing rAVR (risk ratio [RR] 0.55 [95% CI, 0.34-0.91], P=0.02). Midterm mortality did not differ in patients undergoing ViV compared with patients undergoing rAVR (hazard ratio, 1.27 [95% CI, 0.72-2.25]). The rate of acute kidney failure was lower following ViV, (RR, 0.54 [95% CI, 0.33-0.88], P=0.02), whereas prosthetic aortic valve regurgitation (RR, 4.18 [95% CI, 1.88-9.3], P=0.003) as well as severe patient-prothesis mismatch (RR, 3.12 [95% CI, 2.35-4.1], P<0.001) occurred more frequently. The mean transvalvular gradient was higher following ViV (standard mean difference, 0.44 [95% CI, 0.15-0.72], P=0.008). There were no significant differences between groups with respect to stroke (P=0.26), myocardial infarction (P=0.93), or pacemaker implantation (P=0.21). Conclusions Results of this meta-analysis demonstrate better short-term mortality after ViV compared with rAVR. Midterm mortality was similar between groups. Given the likely selection bias in these individual reports, an adequately powered multicenter randomized clinical trial with sufficiently long follow-up in patients with low-to-intermediate surgical risk is warranted. Registration URL: crd.york.ac.uk/prospero/. Unique identifier: CRD42021228752.