Transcatheter Aortic Valve Replacement Across Hemodynamic Subtypes of Severe Aortic Valve Stenosis: A Network Meta-analysis

Background Studies assessing outcomes of transcatheter aortic valve replacement (TAVR) in patients with severe aortic valve stenosis (AS) with hemodynamic subtypes have demonstrated mixed results with respect to outcomes and periprocedural complications. This study aimed to assess the outcomes of TAVR in patients across various hemodynamic subtypes of severe AS. Methods PubMed, Embase, and Cochrane databases were searched through September 2023 to identify all observational studies comparing outcomes of TAVR in patients with paradoxical low flow low gradient (pLFLG), classic LFLG, and high gradient AS (HGAS). The primary outcome was major adverse cardiovascular events (MACE). The secondary outcomes were components of MACE (mortality, myocardial infarction [MI], stroke). A bivariate, influential, and frequentist network meta-analysis model was used to obtain the net odds ratio (OR) with a 95% CI. Results A total of 21 studies comprising 17,298 (8742 experimental and 8556 HGAS) patients were included in the quantitative analysis. TAVR was associated with a significant reduction in the mean aortic gradient, and an increase in the mean aortic valve area irrespective of the AS type. Compared with HGAS, TAVR in classic LFLG had a significantly higher (OR, 1.68; 95% CI, 1.04-2.72), while pLFLG (OR, 0.98; 95% CI, 0.72-1.35) had a statistically similar incidence of MACE at a median follow-up of 1-year. TAVR in LFLG also had a significantly higher need for surgery (OR, 3.57; 95% CI, 1.24-10.32), and a greater risk of periprocedural (OR, 2.00; 95% CI, 1.17-3.41), 1-month (OR, 1.69; 95% CI, 1.08-2.64), and 12-month (OR, 1.41; 95% CI, 1.05-1.88) mortality compared with HGAS. The incidence of MI, major bleeding, vascular complications, paravalvular leak, pacemaker implantation, and rehospitalizations was not significantly different between all other types of AS (HGAS vs LFLG, pLFLG). Conclusions TAVR is an effective strategy in severe AS irrespective of the hemodynamic subtypes. Relatively, pLFLG did not have significantly different risk of periprocedural complications compared with HGAS, while classical LFLG AS had higher risk of MACE, primarily driven by the greater mortality risk.