Citations

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

Abstract Funding Acknowledgements Mayo Clinic Background Variability in Doppler signals is common in patients with atrial fibrillation (AF) and AF is common in low-gradient AS (LGAS). Presence of high single beat Doppler signals (peak velocity ≥4m/s or mean gradient ≥40mmHg) is not factored into decision-making in low-gradient aortic stenosis (LGAS). Objective Determine prevalence of at least one high Doppler signal in AF LGAS and its relationship to computed tomography aortic valve calcium score (AVCS) versus sinus rhythm (SR) high-gradient aortic stenosis (HGAS). Methods Consecutive patients with aortic valve area ≤1cm2 and left ventricular ejection fraction ≥50% during echo were identified (January 1, 2012-December 31, 2016). At least three consecutive Doppler signals were averaged in sinus rhythm (SR) and five in atrial fibrillation (AF). Results Of 1,854 patients, age 76± 11 years, male 52%, 301/1,854 (16%) were in AF and LGAS was present in 122/301 (41%). At least one high Doppler signal in AF LGAS was present in 43/122 (35%). AVCS within 1 year of echo was available for 36% of patient with SR HGAS and 34% of AS LGAS. Median AVCS was not different in SR HGAS 2424 (IQR 1623, 3445) vs AF LGAS with at least one high Doppler signal 2509 [IQR1547, 3119], p =0.10 AVCS threshold for severe AS (men >2000 women >1200) was met in 80% SR HGAS vs 86% AF LGAS with high signals. Conclusions High Doppler signals in AF LGAS are associated with high AVCS more frequently exceeding thresholds for severe AS. Single-beat high Doppler signals instead of the average correlate better with AVCS and classic HGAS.

The purpose of this study is to evaluate a direct measure of calcium burden by using dual‐energy computed tomography (DECT) during contrast‐enhanced coronary imaging, potentially eliminating the need for an extra noncontrast X‐ray acquisition. The ambiguity of separation of calcium from contrast material on contrast‐enhanced images was solved by using virtual noncontrast images obtained by DECT. A new threshold CT number was required to detect the calcium carrying potential risk for adverse coronary events on virtual noncontrast images. Two methods were investigated to determine the 130 HU threshold for DECT scoring. An in vitro anthropomorphic phantom with 29 excised patient calcium plaques inserted was used for both a linear and a logistic regression analysis. An IRB approved in vivo prospective study of six patients was also performed to be used for logistic regression analysis. The threshold found by logistic regression model to define the calcium burden on virtual noncontrast images detects the calcium carrying potential risk for adverse coronary events correctly (2.45% error rate). DECT calcium mass and volume scores obtained by using the threshold correlates with both conventional Agatston and volume scores . A conventional CT cardiac exam requires two scans, including a noncontrast scan for calcium quantification and a contrast‐enhanced scan for coronary angiography. With the ability to quantify calcium on DECT contrast‐enhanced images, a DECT cardiac exam could be accomplished with one contrast‐enhanced scan for both calcium quantification and coronary angiography.PACS numbers: 87.57.Q, 87.57.N