The importance of papillary muscle dyssynchrony in predicting the severity of functional mitral regurgitation in patients with non-ischaemic dilated cardiomyopathy: a two-dimensional speckle-tracking echocardiography study

Left ventricular (LV) twist serves as a compensatory mechanism in systolic dysfunction and its degree of reduction may reflect a more advanced stage of disease. Aim: The aim was to investigate twist alterations depending on the degree of functional mitral regurgitation (MR) by speckle-tracking echocardiography. Methods: Sixty-three patients with symptomatic dilated cardiomyopathy (DCM) were included. Patients were divided according to MR vena contracta width (VCW): group 1 with VCW <7 mm (mild/moderate MR) and group 2 with VCW ≥7 mm (severe MR). Results: There were no differences in LV geometry and function between groups. Group 2 showed lower endocardial basal rotation (BR) (–2.04° ± 1.83° vs. –3.23° ± 1.83°, p = 0.012); epicardial BR (–1.54° ± 1.18° vs. –2.31° ± 1.22°, p = 0.015); endocardial torsion (0.41°/cm ± 0.36°/cm vs. 0.63°/cm ± 0.44°/cm, p = 0.033) and mid-level circumferential strain (CSmid) (–6.12% ± 2.64% vs. –7.75% ± 2.90%, p = 0.028), when compared with group 1. Multivariable linear regression analysis identified endocardial BR, torsion and CSmid, as the best predictors of larger VCW. In the ROC curve analysis, endocardial BR and CSmid values greater than or equal to –3.63° and –9.35%, respectively, can differentiate patients with severe MR. Conclusions: In DCM patients, torsional profile was more altered in severe MR. Endocardial BR, endocardial torsion, and CSmid, can be used as indicators of advanced structural wall architecture damage.

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Abstract 14783: Relationship Between Native Papillary Muscle T1 Time and Severity of Functional Mitral Regurgitation in Patients With Non-ischemic Dilated Cardiomyopathy

Circulation ◽

10.1161/circ.132.suppl_3.14783 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Shingo Kato ◽

Sébastien Roujol ◽

Francesca Delling ◽

Shadi Akhtari ◽

Jihye Jang ◽

...

Keyword(s):

Mitral Regurgitation ◽

Dilated Cardiomyopathy ◽

Papillary Muscle ◽

T1 Mapping ◽

Functional Mitral Regurgitation ◽

Diffuse Fibrosis ◽

Regurgitant Fraction ◽

Native T1 ◽

Non Ischemic Dilated Cardiomyopathy ◽

Native T1 Time

Introduction: 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. Hypothesis: We hypothesized that papillary muscle native T1 time is correlated with severity of functional 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 sec 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<0.001; posterior papillary muscle: 1124±30 msec vs 1062±19 msec, p<0.001), 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=0.109, 95%CI: 0.048-0.170, p=0.001) and tenting height (β=1.334, 95%CI: 0.434-2.234, p=0.005) are 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. These results suggest that papillary muscle diffuse fibrosis might be associated with severity of mitral regurgitation in this population.

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