P1366 Low-flow, low-gradient severe aortic stenosis: might mitral regurgitation be a culprit?

Abstract Introduction According to current guidelines, given a patient with low-gradient (aortic valve maximum velocity < 4m/s and/or aortic valve mean gradient <40mmHg), aortic valve area (AVA) < 1cm2 and low-flow (stroke volume (SV) < 35mL/min/m2), with preserved left ventricle function (ejection fraction (EF) ≥50%), an integrated approach for assessment of aortic stenosis severity is proposed. We aimed to investigate whether mitral regurgitation can play a role in those cases, possibly being responsible for low antegrade systolic flow. Methods We retrospectively analysed 121 consecutive transthoracic echocardiograms (TTEs) of patients with severe aortic stenosis, with AVA < 1.0cm2 as assessed by continuity equation. Patients with low ejection fraction (< 50%) were excluded. We therefore included 84 patients (females 53,6%, mean age 79,1+-10 years). Stroke volume was assessed by Doppler at the left ventricle outflow tract (LVOT). We then compared the prevalence of more than mild mitral regurgitation among patients with low-gradient and low-flow and the other patients. Results 15 patients had both low-gradient, low-flow and preserved ejection fraction. There was a significant association regarding the presence of more than mild mitral regurgitation among these patients (p = 0.028, OR = 4.7, CI 95% 1.1-20.1). In these patients, it was also observed a higher prevalence of atrial fibrillation (p = 0.03, OR = 6.9, CI 95% 1.74-27.1), lower longitudinal systolic function of right ventricle as measured by TAPSE (16.6 vs 21.5mm, p = 0.028), and a tendency towards higher left atrial volume (113 vs 87mL, p = 0.06). Conclusions Given the findings that the prevalence of more than mild mitral regurgitation is higher in patients with severe aortic stenosis as assessed by AVA with both low-gradient, low-flow and preserved ejection fraction, we suggest that the presence of more than mild mitral regurgitation should be considered on the approach of aortic stenosis classification of these patients.