JACC: CARDIOVASCULAR IMAGING VOL. ª 2017 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION -, NO. -, 2017 ISSN 1936-878X/$36.00 PUBLISHED BY ELSEVIER LETTER TO THE EDITOR repair, a 40% reduction in SI was seen in the PL, whereas the AL showed a 23% reduction in SI. Comparing post-repair SI data to that of normal individuals (1) revealed that mean global SI was now Effect of Mitral Valve Repair on Mitral Valve comparable to that of normal individuals (Figure 1B); Leaﬂets Strain Regionally, mean SI for AL was similar to that of A Pilot Study normal individuals, whereas the SI for the PL was reduced (Figure 1B). No relation was found between Primary mitral regurgitation is amenable to surgical repair; its durability may be inﬂuenced by the surgical approach, underlying pathology, and possibly annular geometry and leaﬂet stress. Recently, we have reported a new method to compute mitral valve (MV) strain in humans from 3-dimensional (3D) transesophageal echocardiography (1). We aimed to use the developed patient-speciﬁc strain methodology to evaluate the effect of mitral valve repair (MVR) on global and regional MV strain. The MVR technique used was the nonresectional approach (1,2). We performed 3D transesophageal echocardiography of the MV in 10 patients with moderately severe or severe primary mitral regurgitation (age 64 13 years, 9 male and 1 female patient; 8 patients with ﬂail P2, 1 with P3 prolapse, and another with A2 prolapse) in the operating room, with a closed chest, prior to and following repair and hemodynamic stability. All patients had successful MVR; complete ﬂexible ring was used: ATS ring in all but 1 patient (size 31.8 1.4 mm). Patient-speciﬁc MV modeling was created at mid- and end-systole from which mitral leaﬂets strain was computed (3,4). Following MVR, the mitral annulus dimensions were signiﬁcantly reduced: annulus area decreased from 15.2 0.8 cm 2 to 5.2 0.1 cm2 and circumference from 15.2 0.4 cm to 8.4 0.1 cm (both p < 0.05). The exposed anterior leaﬂet (AL) and posterior leaﬂet (PL) (AL 6.13 2.07 cm 2 and PL 8.99 2.08 cm 2) were signiﬁcantly smaller after repair (2.79 0.41 cm2 and 3.13 0.24 cm 2, respectively; p < 0.05). Although the systolic or diastolic blood pressure and strain (r range 0.23 to 0.45, p range 0.18 to 0.62). It is thought that any MVR technique that is associated with reduced leaﬂets stress will have a better long-term outcome. Consequently, previous MVR simulations focused on leaﬂets stress calculations (5). The current study is the largest report of MV modeling following MVR in humans. A computerized analysis of 3D echocardiography allowed in vivo, patient-speciﬁc quantiﬁcation of MV SI. We computed planar strain tensor at several thousand points on the MV so we did not need to introduce any elasticity hypotheses for mitral leaﬂets tissue for strain calculation. Indeed, realistic MV elasticity models are anisotropic and highly nonlinear so that in most publications, parametrization of elasticity models for human MV relies on stress measurements made in vivo in animal models. The reduction in valve strain after MVR is likely multifactorial and may be related to a smaller annular size, increased valve coaptation zone, a smaller exposed valve area, and the insertion of artiﬁcial chordae, each having been shown in various models to reduce strain. These reductions and “normalization” in strain may contribute to the overall good intermediate to long-term outcome seen in the nonresectional MVR technique (2). Further studies are needed to assess the effect of different surgical repair approaches on the magnitude and distribution of reduction in MV strain and assess whether residual MV strain intensity is a signiﬁcant determinant of MVR durability. operative: 0.096 0.015; p < 0.05) (Figure 1B). Before Sagit Ben Zekry, MD* Jeff Freeman, MS Aarti Jajoo, PhD Jiwen He, PhD Stephen H. Little, MD Gerald M. Lawrie, MD Robert Azencott, PhD William A. Zoghbi, MD MVR, the PL, compared with the AL, showed higher SI *Department of Cardiology PL area was larger than the AL, the PL area was proportionally reduced more so than the AL area. An example of mitral valve strain intensity (SI) map before and after MVR is shown (Figure 1A). For the 10 patients, a signiﬁcant reduction in global SI was noted after valve repair (pre-operative: 0.15 0.01 vs. post- (0.19 0.02 vs. 0.13 0.01, respectively; p < 0.05). Houston Methodist DeBakey Heart and Vascular Center After valve repair, mean SI was signiﬁcantly reduced 6550 Fannin Street for both AL and PL to comparable values (0.09 0.01 SM 1901 for AL, 0.10 0.01 for PL) (Figure 1B). Thus after valve Houston, Texas 77030 2 JACC: CARDIOVASCULAR IMAGING, VOL. Letter to the Editor -, NO. -, 2017 - 2017:-–- F I G U R E 1 MV Strain Intensities Map and Mean Strain Intensity Pre- and Post-MV Repair A Pre-Operation Post-Operation 25 Anterior Leaflet 25 0.42 20 20 5 5 0 0.22 –5 –10 –15 0.22 –10 Posterior Leaflet –15 –20 –25 –30 0 –5 Posterior Leaflet –20 –10 0 10 20 Strain Value 15 10 Strain Value 15 10 0.42 Anterior Leaflet –20 0.02 –25 –30 –20 –10 0 10 20 0.02 mm mm B *P < 0.05 vs Posterior Leaflet †P < 0.05 vs Pre-Operation ‡P < 0.05 vs Post-Operation 0.20 †‡ 0.15 * † † † 0.10 *† † 0.05 0.00 Pre-Operation Post-Operation Global Anterior Leaflet Normal Posterior Leaflet (A) An example of mitral strain intensity maps in a patient before and after mitral valve (MV) repair, showing reduction in strain post-operatively. (B) Mean strain values for the mitral valve, the anterior and posterior leaﬂets pre- and post-operation, and in normal individuals (1). Mean and SE bars are shown. E-mail: email@example.com https://doi.org/10.1016/j.jcmg.2017.07.017 Please note: Dr. Ben Zekry received partial funding from a grant in 2009 to 2010 by John and Maryanne McCormack Cardiology Fund. Dr. Azencott and University of Houston collaborators received National Science Foundation grant NSF-0811133 in 2008 to 2011. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Farooq A. Chaudhry, MD, served as the Guest Editor for this article. 2. Lawrie GM, Zoghbi W, Little S, et al. One hundred percent reparability of degenerative mitral regurgitation: intermediate-term results of a dynamic engineered approach. Ann Thorac Surg 2016;2:576–83; discussion 583–4. 3. Ben Zekry S, Lawrie GM, Little SH, et al. Comparative evaluation of mitral valve strain by deformation tracking in 3D-echocardiography. J Cardiovasc Eng Tech 2012;3:402–12. 4. Azencott R, Glowinski R, He J, et al. 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