Transcatheter aortic valve implantation versus surgical aortic valve replacement in patients at low and intermediate risk: A risk specific meta-analysis of randomized controlled trials

Background Transcatheter aortic valve implantation (TAVI) is an option for treatment for patients with severe aortic stenosis who are at high risk for death with surgical aortic valve replacement (SAVR). It is unknown whether TAVI can be safely introduced to intermediate- and low-risk patients. Objective To compare the efficacy and safety of TAVI and SAVR in patients with intermediate- and low-surgical risk. Data sources Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched from inception to April 15, 2019. Study selection We included randomized controlled trials comparing TAVI with SAVR in patients with intermediate- and low-surgical risk. Data extraction Meta-analyses were conducted using random-effects models to calculate risk ratios (RR) with corresponding 95% confidence interval (CI). Two independent reviewers completed citation screening, data abstraction, and risk assessment. Primary outcome was a composite of all-cause mortality or disabling stroke at 12 months. Data Synthesis A total of 5 trials randomizing 6390 patients were included. In patients with low risk, TAVI was associated with a significant reduction in the composite of all-cause mortality or disabling stroke compared with SAVR (RR, 0.56; 95%CI, 0.40-0.79; I-2 = 0%). This benefit was not replicated in patients with intermediate risk (RR, 0.96; 95% CI, 0.80-1.15; I-2 = 0%). Similar results were seen separately in all-cause mortality and disabling stroke when TAVI was compared with SAVR. Conclusion For patients with severe aortic stenosis who were at low risk for death from surgery, TAVI achieved superior clinical outcomes compared to SAVR; however, these benefits were not seen in those with intermediate risk. This information may inform discussions about deciding between SAVR and TAVI for patients with low to intermediate risk separately.