Published in:
Open Access
01-01-2017 | Research
Relationship between native papillary muscle T1 time and severity of functional mitral regurgitation in patients with non-ischemic dilated cardiomyopathy
Authors:
Shingo Kato, Shiro Nakamori, Sébastien Roujol, Francesca N. Delling, Shadi Akhtari, Jihye Jang, Tamer Basha, Sophie Berg, Kraig V. Kissinger, Beth Goddu, Warren J. Manning, Reza Nezafat
Published in:
Journal of Cardiovascular Magnetic Resonance
|
Issue 1/2017
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Abstract
Background
Functional mitral regurgitation is one of the severe complications of non-ischemic dilated cardiomyopathy (DCM). Non-contrast native T1 mapping has emerged as a non-invasive method to evaluate myocardial fibrosis. We sought to evaluate the potential relationship between papillary muscle T1 time and mitral regurgitation in DCM patients.
Methods
Forty DCM patients (55 ± 13 years) and 20 healthy adult control subjects (54 ± 13 years) were studied. Native T1 mapping was performed using a slice interleaved T1 mapping sequence (STONE) which enables acquisition of 5 slices in the short-axis plane within a 90 s free-breathing scan. We measured papillary muscle diameter, length and shortening. DCM patients were allocated into 2 groups based on the presence or absence of functional mitral regurgitation.
Results
Papillary muscle T1 time was significantly elevated in DCM patients with mitral regurgitation (n = 22) in comparison to those without mitral regurgitation (n = 18) (anterior papillary muscle: 1127 ± 36 msec vs 1063 ± 16 msec, p < 0.05; posterior papillary muscle: 1124 ± 30 msec vs 1062 ± 19 msec, p < 0.05), but LV T1 time was similar (1129 ± 38 msec vs 1134 ± 58 msec, p = 0.93). Multivariate linear regression analysis showed that papillary muscle native T1 time (β = 0.10, 95 % CI: 0.05–0.17, p < 0.05) is significantly correlated with mitral regurgitant fraction. Elevated papillary muscle T1 time was associated with larger diameter, longer length and decreased papillary muscle shortening (all p values <0.05).
Conclusions
In DCM, papillary muscle native T1 time is significantly elevated and related to mitral regurgitant fraction.