Transcatheter aortic valve implantation results are not superimposable to surgery in patients with aortic stenosis at low surgical risk

Background: The aim of this meta-analysis was to compare the impact of transcatheter aortic valve implantation (TAVI) vs. surgical aortic valve replacement (SAVR) in patients with severe aortic valve stenosis (AS) at low surgical risk. Methods: All randomized controlled trials (RCTs) and observational studies (Obs) published from January 2014 until March 31st, 2020 were retrieved through the PubMed computerized database and at the site https://www.clinicaltrials.com. The relative risk (RR) with the 95% confidence interval (CI) was used to evaluate the effect of the intervention under comparison. The primary endpoints were all-cause 30-day mortality and 1-year mortality. The 30-day safety endpoints were: stroke, acute kidney injury stage 2 or 3, major bleeding, moderate/severe paravalvular leak, need for new permanent pacemaker (PM) implantation. Results: After detailed review 9 studies, related to 4 RCTs and 5 Obs, were selected. The overall analysis of RCTs plus Obs showed a significantly lower 30-day mortality for TAVI (RR = 0.55; 95% CI 0.45-0.68, p < 0.00001; I-2 = 0%). However, an increased risk of new PM implantation (RR = 2.87; 95% CI 2.01-3.67, p < 0.00001, I-2 = 0%) and of paravalvular leak (RR = 7.28; 95% CI 3.83-13.81, p < 0.00001, I-2 = 0%) was observed in TAVI compared to SAVR. On the contrary, a lower incidence of major bleeding (RR = 0.38; 95% CI 0.27-0.54, p < 0.00001, I-2 = 0%) and of acute kidney injury was observed (RR = 0.33; 95% CI 0.19-0.56, p < 0.0001, I-2 = 0%) in TAVI. Conclusions: TAVI and SVAR in the treatment of AS in the patients at low surgical risk are not super-imposable. In particular, if 30-day and 1-year mortality, major bleeding and acute kidney injury were significantly lower for TAVI, the need of new PM implantation and paravalvular leak were significantly lower in SAVR. Consequently, we suggest the need of more trials to evaluate the effectiveness of TAVI as routine therapeutic procedure in the treatment of patients with low surgical risk AS.