Author + information
- Michael Yin-Cheung Tsang,
- Christina Luong,
- John Jue,
- Kenneth Gin,
- Parvathy Nair,
- Pui-Kee Lee,
- Min Gao,
- Marion Barnes and
- Teresa S.M. Tsang
Atrial fibrillation (AF) is associated with progressive atrial enlargement, and mitral annular diameter (MAD) is closely related to the left atrial size. The natural history of mitral annulus remodeling in the context of AF has not been assessed. We aimed to determine the rate of change in MAD over time in patients with permanent AF.
In this retrospective cohort study, patients with permanent AF who underwent serial transthoracic echocardiography (TTE) between 2005 and 2010 were identified from the echocardiography database of Vancouver General Hospital, a large university-based tertiary care hospital in British Columbia, Canada. Patients with organic mitral valve (MV) disease, mitral annular calcification with an elevated transmitral gradient, prior MV surgery, and congenital heart disease were excluded. The final analysis included 51 patients who had had at least 3 TTEs during the study period. Echocardiographic measurements were performed offline by one person using standardized methodology. MAD, defined as the distance between the hinge points of the anterior and posterior MV leaflets in the parasternal long axis view, was measured during end-systole and end-diastole. Linear mixed effects modeling was used in analyzing the above measurements for change over time.
Our cohort of 51 subjects (28 male) underwent 183 TTEs in total during the study period. The mean age at study entry was 72±10 years (47-85 years). The median number of TTEs performed was 3 (range 3-6). All 51 patients showed a progressive increase in MAD over time. The linear mixed effects model revealed a significant increase in MAD over time at end-systole and end-diastole; the increases were 0.393 mm/year (95% Cl 0.056-0.642, p=0.0032) and 0.378 mm/year (95% Cl 0.054-0.673, p=0.0041) respectively.
This is the first study in literature to describe the natural history of mitral annulus remodeling in patients with permanent AF. The entire permanent AF study cohort showed a significant increase in MAD over time. The rate of change was nearly 0.4 mm per year. Further studies can elucidate how this change relates to the progression of mitral regurgitation and future development of heart failure.
Poster Sessions, Expo North
Sunday, March 10, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Imaging: Echo: Atrial Imaging
Abstract Category: 18. Imaging: Echo
Presentation Number: 1226-340
- 2013 American College of Cardiology Foundation