Abstract 12237: Transcatheter Aortic Valve Replacement in Very Low Gradient Aortic Stenosis

Introduction: Transcatheter aortic valve implantation (TAVI) or surgical aortic valve replacement is recommended for symptomatic patients with high-gradient aortic stenosis (HGAS) and certain patients with low-flow, low-gradient aortic stenosis (LGAS). While TAVI may be beneficial in LGAS (mean pressure gradient (MPG) <40 mmHg), the outcomes of TAVI in very low-gradient AS (VLGAS) patients (<25 mmHg) is under-reported. Methods: This retrospective cohort study analyzed 1269 patients who underwent TAVI at a multi-disciplinary, tertiary-care center. Patients with severe aortic stenosis were divided into VLGAS (≤25mmHg), LGAS (>25 mmHg up to 40 mmHg) and HGAS groups (≥40 mmHg), using MPG derived from transthoracic echocardiography. Symptom improvement was measured by New York Heart Association (NYHA) functional classification at baseline, 30-days, and 1-year. Mortality and rehospitalization were secondary endpoints. Between group differences were evaluated with chi-squared tests. Results: Patients with VLGAS had improvement in NYHA functional class after TAVI that was similar to those with LGAS and HGAS (figure). While symptom improvement was similar between groups at 30 days (86% in VLGAS, 84% in LGAS and 85% in HGAS, p=0.46), VLGAS was associated with inferior symptom improvement at 1 year (76%, 87%, and 89%, respectively, p<0.01). One-year rehospitalization rates were higher in patients with VLGAS than in patients with LGAS or HGAS (28%, 21%, and 17%, respectively, p =0.014). Mortality at 1-year did not differ between groups (p=0.65). Conclusion: TAVI improves symptoms in most LGAS patients, including those with VLGAS. More VLGAS patients with either no change or worsened symptoms after TAVI may be correlated to increased rehospitalization.