Transcatheter versus surgical aortic valve replacement in low and intermediate risk patients with severe aortic stenosis: systematic review and meta-analysis of randomized controlled trials and propensity score matching observational studies

BACKGROUND: To compare the outcome of transcatheter aortic valve replacement (TAVR) with surgical aortic valve replacement (SAVR) in low and intermediate risk patients with severe aortic stenosis (AS). Randomized controlled trials (RCT) and propensity score matching (PSM) studies compare TAVR with SAVR in patients at low and intermediate surgical risk. METHODS: Two authors searched relevant literature independently, then extracted data from the included studies, and assessed risk of bias and quality of study separately according to different study designs, besides that, the extracted data was analyzed via utilization of GRADE system to evaluate the quality of evidence separately. RESULTS: Overall 15 studies (5 RCTs, 10 PSM studies) with total 12,057 patients were selected. Mortality and disabling stroke during follow-up period were comparable between TAVR and SAVR (RR 1.09, 95% CI: 0.81 to 1.46; RR 0.7, 95% CI: 0.45 to 1.07, respectively), TAVR revealed to be superior to SAVR regarding acute kidney injury (AKI), and onset of new atrial fibrillation (AF) (RCT: high certainty; AKI in PSM: moderate certainty, AF in PSM: low certainty). These results of RCT and PSM studies are consistent. In RCT review, SAVR was better in the following aspects: aortic valve (AV) re-intervention (high certainty), vascular complications, pacemaker implantation (moderate certainty), but comparable in the following aspects: myocardial infarction (MI), aortic insufficient (AI) (moderate certainty), major bleeding (low certainty). In PSM review, SAVR revealed a better result in AI and vascular complications (high certainty), but in the aspects of AV re-intervention, pacemaker implantation, major bleeding and MI (low certainty), it was comparable. CONCLUSIONS: TAVR is comparable to SAVR in terms of mortality and disabling stroke in severe AS patients at low and intermediate risk, but higher proportion of AV re-intervention observed in TAVR. Those results should encourage caution when extending the indications of TAVR into low risk patients, especially for young low risk patients. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD 42018112626.