Abstract 17436: Co-Existing Mitral Regurgitation in Significant Aortic Stenosis: Adverse Impact on Left Ventricular Geometry, Function and Patient Outcome

Abstract

Background: Mitral Regurgitation (MR) often co-exists with aortic stenosis (AS). The impact of MR on left ventricular (LV) parameters and prognosis in severe AS is unclear yet important for clinical decision-making. We sought to determine the effect of co-existing functional MR on LV remodeling, diastolic function, and mortality in patients (pts) with severe AS. Methods: Pts with severe AS (aortic valve area (AVA) < 1.0 cm 2 ) and LVEF ≥ 55% were searched for in our echo database over 12 months. Primary mitral valve disorders (rheumatic and calcific mitral stenosis (mean gradient >5 mmHg) and prolapse) were excluded. 43 pts with severe AS and co-existing ≥ moderate functional MR (+MR) were compared to 139 pts of similar age with severe AS but ≤ mild functional MR (-MR). Indexed end-diastolic (EDVi), end-systolic (ESVi), and left atrial (LAVi) volumes, LV mass, and diastolic function were measured by 2D and Doppler echo. Mortality was assessed by Social Security death index and adjusted for cardiac risk factors and covariates (Cox regression). Results: AVA (0.77 vs. 0.79 cm 2 , p=0.5) and mean aortic gradient (40 vs. 41 mmHg, p=0.5) were similar in both groups while the forward stroke volume index (SVi) (38 vs. 42 mL/m 2 , p=0.009) was lower in +MR. LV mass index (122 vs.103 gm/m 2 , p<0.001), EDVi (57 vs. 53 mL/m 2 , p=0.05), and ESVi (19 vs.16 mL/m 2 , p=0.02) were higher in the +MR group. +MR pts also had a higher LAVi (62 vs. 42 mL/m 2 , p<0.001), pulmonary artery systolic pressure (PASP) (47 vs. 40 mmHg, p<0.001), E/E' ratio (18.6 vs. 15.7, p=0.02), and deceleration time (231 vs. 263 ms, p=0.007). Survival (follow-up of 2.6 yrs) was lower in +MR group (67 vs. 85%, HR 2.9 (95% CI: 1.3 - 6.6, p=0.009). Conclusions: Co-existing functional MR in pts with severe AS is associated with adverse LV remodeling, higher PASP and increased mortality. These observations may be due to simultaneous volume and pressure overload despite similar AS severity and have important implications for clinical-decision making.