Author + information
- Received June 12, 2017
- Revision received September 14, 2017
- Accepted September 22, 2017
- Published online December 13, 2017.
- Dae-Hee Kim, MD, PhDa,∗ (, )
- Ran Heo, MDa,
- Mark D. Handschumacher, BSb,
- Sahmin Lee, MD, PhDa,
- Yun-Sil Choi, RN, RDCSa,
- Kyu-Ri Kim, RN, RDCSa,
- Yewon Shin, RN, RDCSa,
- Hong-Kyung Park, RN, RDCSa,
- Joyce Bischoff, PhDc,
- Elena Aikawa, MD, PhDd,
- Jong-Min Song, MD, PhDa,
- Duk-Hyun Kang, MD, PhDa,
- Robert A. Levine, MDb and
- Jae-Kwan Song, MD, PhDa
- aCardiac Imaging Center, Asan Medical Center Heart Institute, University of Ulsan College of Medicine, Seoul, South Korea
- bCardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- cVascular Biology Program and Department of Surgery, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
- dCenter for Excellence in Vascular Biology, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
- ↵∗Address for correspondence:
Dr. Dae-Hee Kim, Asan Medical Center Heart Institute, University of Ulsan College of Medicine, 388-1 Poongnap-dong Songpa-gu, Seoul, 138-736 South Korea.
Objectives This study hypothesized that compensatory mitral leaflet area (MLA) adaptation occurs in patients with persistent atrial fibrillation (AF) without left ventricular (LV) dysfunction but has limitations that augment mitral regurgitation (MR). The study also explored whether asymmetrical annular dilation is matched by relative leaflet enlargement.
Background Functional MR occurs in patients with AF and isolated annular dilation, but the relationship of MLA adaptation with annular area (AA) is unknown.
Methods Three-dimensional echocardiographic images were acquired from 86 patients with quantified MR: 53 with nonvalvular persistent AF (23 MR+ with moderate or greater MR, 30 MR−) without LV dysfunction or dilation and 33 normal controls. Comprehensive 3-dimensional analysis included total diastolic MLA, adaptation ratios of MLA to annular area and MLA to leaflet closure area, and annular and tenting geometry.
Results Total MLA was 22% larger in patients with AF than in controls, thus paralleling the increased AA. However, as AA increased, adaptive indices (MLA/AA ratio and ratio of MLA to closure area) plateaued, becoming lowest in MR+ patients (ratio of MLA to closure area = 1.63 ± 0.17 controls, 1.60 ± 0.11 MR−, 1.32 ± 0.10 MR+; p < 0.001). MR increased as the ratio of MLA to closure area decreased (R2 = 0.68; p < 0.001). The posterior-to-anterior MLA ratio remained constant, whereas the posterior-to-anterior mitral annulus perimeter increased (1.21 ± 0.16 controls, 1.32 ± 0.20 MR−, 1.46 ± 0.19 MR+; p < 0.001). Multivariate MR determinants were annular area, total MLA to closure area, and posterior-to-anterior perimeter ratios.
Conclusions MLA adaptively increases in AF with isolated annular dilation and normal LV function. This compensatory enlargement becomes insufficient with greater annular dilation, and the leaflets fail to match asymmetrical annular remodeling, thereby increasing MR. These findings can potentially help optimize therapeutic options and motivate basic studies of adaptive growth processes.
This study was supported by a research grant from the Korean Society of Echocardiography, in part by NIH grants R01 HL128099 and HL141917, and by support from the Ellison Foundation. The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Drs. D.-H. Kim and Heo contributed equally to this work and are joint first authors.
Drs. Levine and J.-K. Song contributed equally to this work and are joint senior authors.
- Received June 12, 2017.
- Revision received September 14, 2017.
- Accepted September 22, 2017.
- 2017 American College of Cardiology Foundation
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