Comparing Outcomes Between Surgical and Transcatheter Aortic Valve Replacement in Classical Low-Flow Low-Gradient Aortic Stenosis

Abstract

Patients with classic low-flow low-gradient (cLFLG) aortic stenosis (AS) have a poor prognosis but still benefit from aortic valve replacement. There is a paucity of evidence to guide the choice between transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR). This study compared procedural and midterm outcomes in patients with cLFLG AS between TAVR and SAVR. Patients with cLFLG AS, defined as an aortic valve area ≤1 cm2, mean gradient <40 mm Hg, and left ventricular ejection fraction <50%, were selected from a single center between 2015 and 2020. Inverse probability weighting and regression were used to adjust for differences in baseline characteristics, the nonrandom assignment of treatment modalities, and procedural differences. The primary end point was all-cause mortality. A total of 322 patients (220 TAVR and 102 SAVR) were included. At a follow-up of 4.4 ± 1.5years, the adjusted hazard ratio (HR) for mortality after inverse probability weighting with SAVR was 0.66, 95% confidence interval (CI) 0.31 to 1.35; p=0.24. Worse renal function at baseline (per 10ml/min/m2 increase HR 0.92, 95% CI 0.84 to 1.00, p=0.04) and multiple valve interventions (HR 5.39, 95% CI 2.62 to 11.12, p <0.001) independently predicted mortality. There was no difference in stroke and permanent pacemaker implantation, but the rates of renal replacement therapy were higher among the SAVR cohort: 13.7% versus 0%; p <0.001. In conclusion, among patients with cLFLG AS, there was no difference in midterm mortality between TAVR and SAVR, supporting the use of either treatment. However, in patients with poor renal function or at risk of renal failure, TAVR may be the preferred option.