Benefit of Transcatheter Aortic Valve Replacement in Patients With Paradoxical Low-Flow Low-Gradient Versus High-Gradient Aortic Stenosis and Preserved Left Ventricular Function

Background: There is conflicting data regarding transcatheter aortic valve replacement in patients with paradoxical low-flow, low-gradient aortic stenosis (pLFLG-AS). The authors aimed to examine the hemodynamic and clinical benefit of transcatheter aortic valve replacement in symptomatic patients with pLFLG-AS compared with high-gradient severe AS.

Methods: A single-center retrospective analysis of patients who underwent transcatheter aortic valve replacement using a transfemoral approach was performed. Patients with a mean gradient ≥40 mm Hg were included in the high-gradient aortic stenosis (HG-AS) group (n=217). Patients with mean gradient <40 mm Hg, Vmax <4.0 m/s, and stroke volume index ≤35 mL/m2 were included in the pLFLG-AS group (n=73). Clinical end points including treatment futility, survival, changes in functional status and quality of life, and echocardiographic outcomes of left ventricular reverse remodeling were evaluated. Two primary composite outcomes were used for treatment futility. The first as a composite outcome defined as death or New York Heart Association class III/IV at 1 year. The second was a composite of death or Kansas City Cardiomyopathy Questionnaire 12 score of ≤25 at 1 year.

Results: There were no differences in mortality, the Kansas City Cardiomyopathy Questionnaire-based treatment futility outcome (HG-AS: 8.8% versus pLFLG-AS: 6.1%; P=0.482), or New York Heart Association-based treatment futility outcome (HG-AS: 9.1% versus pLFLG-AS: 11.6%; P=0.546) at 1 year. Both groups had similar improvement in mean Kansas City Cardiomyopathy Questionnaire 12 score when compared to baseline (HG-AS: 88.56±12.38% versus pLFLG-AS: 137.24±31.75%; P=0.382). There was a similar relative interval decrease in the proportion of patients with New York Heart Association class III/IV (HG-AS: 53.6% versus pLFLG-AS: 55.1%; P=0.838). Echocardiographic evidence of reverse remodeling of the left ventricle in pLFLG-AS group was documented by improvements in global longitudinal strain (pre: -13.95±0.36% versus post: -14.83±0.38%, P=0.004) and stroke volume index at 30 days.

Conclusions: pLFLG-AS did not confer a worse prognosis. Mortality rate and functional class improvement at 1 year was similar in both groups. Left ventricular reverse remodeling in the pLFLG-AS group was apparent.