P1798 Determinants of increased mitral mean diastolic gradient after transcatheter edge-to-edge mitral valve repair

Abstract

Abstract Background Transcatheter edge-to-edge mitral valve repair (TMVR; MitraClip, Abbott Vascular) is clinically approved for treatment of severe, symptomatic mitral regurgitation (MR) in high or prohibitive surgical risk patients. Iatrogenic mitral stenosis is a known complication of TMVR, but determinants of increased post-procedure mean diastolic gradient are not well defined. Purpose We aimed to investigate the determinants of increased mitral mean diastolic gradient after TMVR. Methods We retrospectively reviewed 59 patients. 2D and 3D TEE data sets acquired before and immediately after procedure were analyzed. 4D Cardio-View and 4D MV-Assessment (TomTec, Germany) were used for the analysis of the 3D volume data set. Quantitative mitral valve analysis was done at the end of systole. Increased mitral mean diastolic gradient after TMVR was correlated with pre-procedure 2D and 3D echocardiographic data. Results 34 patients had primary MR, 25 patients had mixed/secondary MR. Baseline mean mitral diastolic gradient was 2.0 ± 0.9mmHg and increased to 3.9 ± 1.8mmHg post-TMVR and the mean 3D planimetric mitral valve area decreased from 5.3 ± 1.5cm2 to 2.6 ± 1.0cm2. Implantation of multiple clips was performed less frequently in patients with smaller baseline mitral valve area; 8% vs 47% in the lowest quartile vs all others (p = 0.006). 12(20%) of patients had a mean diastolic gradient >5mmHg post-TMVR and 15(25%) of patients had a post-TMVR mitral valve area <2.0 cm2. There was no significant difference in post-procedure heart rate between patients with mean diastolic gradient ≤5mmHg vs >5mmHg (p = 0.08). Patient characteristics according to post-TMVR mean diastolic gradient are shown in the Table. Post-TMVR mean diastolic gradient >5mmHg was more common in patients with increased pre-procedure mean diastolic gradient(p = 0.006), post-TMVR mitral valve area <2.0 cm2(40% vs 14%, p = 0.03), and ≥moderate residual mitral regurgitation(38% vs 11%, p = 0.02). Post-TMVR mitral valve area <2.0cm2 was present in 50% vs 19% of patients with vs without a mean gradient >5mmHg(p = 0.04). Conclusions Elevated post-TMVR mean diastolic gradient is multifactorial and related to mitral stenosis, but residual mitral regurgitation also appears to be an important contributor to increased gradients in some patients. Larger cohorts are likely needed to assess the concurrent impact of mitral annular calcification, leaflet calcification, and other variables on post-TMVR mean gradient. Abstract P1798 Figure. 2D and 3D Echocardiographic Parameters