Nkomo, V T

Introduction: Mitral paravalvular leak (PVL) occurs in 7-17% of patients after mitral valve surgery. The percutaneous closure of these defects has become a novel treatment to prevent repeat operations. Hypothesis: We hypothesize flow dynamics correlate with clinical outcomes of patients undergoing percutaneous mitral PVL closure. Methods: We retrospectively studied 148 patients who underwent percutaneous PVL closure between 2004 and 2014 at Mayo Clinic. We measured the continuous wave (CW) Doppler time velocity integral (TVI), E velocity (as a surrogate for V wave) across the mitral valve and left ventricular ejection fraction (LVEF) by transthoracic echocardiogram within 7 days before and after PVL closure. We identified patients as non-responders if there was moderate to severe residual mitral regurgitation. t-Test was used for continuous variables and Fisher exact test was used mortality. Results: Overall, the mean CW TVI was markedly reduced by PVL closure (93±14 vs. 58±5cm, p<0.02). The E velocity also decreased after closure (3.1±0.4 vs. 1.9±0.1m/sec, p<0.04). LVEF, however, was reduced after PVL closure (62%±2 vs. 53%±1.5, p<0.02). Among non-responders (34/148 patients), there was no significant difference between the CW and E velocity before and after the procedure (CW TVI: 96±16 vs. 83+13cm, E velocity: 2.5±0.5 vs. 2.3±0.3m/sec, p=NS). The estimated 5-year mortality of patients with no or mild residual mitral regurgitation was markedly lower compared to non-responders, 43% vs 71%, p<0.05. Conclusions: The flow dynamics across the mitral valve immediately after PVL closure may correlate with long term clinical outcomes. Real time assessment of flow by transesophageal echocardiogram can be used to guide the extent of PVL closure required to change the long term clinical outcomes. Further validation and prospective studies are required.

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 &gt;5mmHg post-TMVR and 15(25%) of patients had a post-TMVR mitral valve area &lt;2.0 cm2. There was no significant difference in post-procedure heart rate between patients with mean diastolic gradient ≤5mmHg vs &gt;5mmHg (p = 0.08). Patient characteristics according to post-TMVR mean diastolic gradient are shown in the Table. Post-TMVR mean diastolic gradient &gt;5mmHg was more common in patients with increased pre-procedure mean diastolic gradient(p = 0.006), post-TMVR mitral valve area &lt;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 &lt;2.0cm2 was present in 50% vs 19% of patients with vs without a mean gradient &gt;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