Mitral valve prolapse, mitral annular disjunction, left ventricular basal hypertrophy and ventricular repolarization abnormalities in Marfan patients

Background: Mitral valve prolapse (MVP) is a frequent disease that can be complicated by mitral regurgitation (MR), heart failure, arterial embolism, rhythm disorders and death. Left ventricular (LV) replacement myocardial fibrosis, a marker of maladaptive remodeling, has been described in patients with MVP, but the implications of this finding remain scarcely explored. We aimed at assessing the prevalence, pathophysiological and prognostic significance of LV replacement myocardial fibrosis through late gadolinium enhancement (LGE) by cardiac magnetic resonance (CMR) in patients with MVP. Methods: Four hundred patients (53±15 years, 55% male) with MVP (trace to severe MR by echocardiography) from 2 centers, who underwent a comprehensive echocardiography and LGE CMR, were included. Correlates of replacement myocardial fibrosis (LGE+), influence of MR degree, and ventricular arrhythmia were assessed. The primary outcome was a composite of cardiovascular events (cardiac death, heart failure, new-onset atrial fibrillation, arterial embolism, and life-threatening ventricular arrhythmia). Results: Replacement myocardial fibrosis (LGE+) was observed in 110 patients (28%; 91 myocardial wall including 71 basal inferolateral wall, 29 papillary muscle). LGE+ prevalence was 13% in trace-mild MR, 28% in moderate and 37% in severe MR, and was associated with specific features of mitral valve apparatus, more dilated LV and more frequent ventricular arrhythmias (45 vs 26%, P<0.0001). In trace-mild MR, despite the absence of significant volume overload, abnormal LV dilatation was observed in 16% of patients and ventricular arrhythmia in 25%. Correlates of LGE+ in multivariable analysis were LV mass (OR 1.01, 95% CI [1.002-1.017], P=0.009) and moderate-severe MR (OR: 2.28, 95% CI [1.21-4.31], P=0.011). LGE+ was associated with worse 4-year cardiovascular event-free survival (49.6±11.7 in LGE+ vs 73.3±6.5% in LGE-, P<0.0001). In a stepwise multivariable Cox model, MR volume and LGE+ (HR: 2.6 [1.4-4.9], P=0.002) were associated with poor outcome. Conclusions: LV replacement myocardial fibrosis is frequent in patients with MVP, is associated with mitral valve apparatus alteration, more dilated LV, MR grade, ventricular arrhythmia, and is independently associated with cardiovascular events. These findings suggest a MVP-related myocardial disease. Finally, CMR provides additional information to echocardiography in MVP.

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Left ventricular mechanical dispersion predicts arrhythmic risk in mitral valve prolapse

Heart ◽

10.1136/heartjnl-2018-314269 ◽

2019 ◽

Vol 105 (14) ◽

pp. 1063-1069 ◽

Cited By ~ 13

Author(s):

Simon Ermakov ◽

Radhika Gulhar ◽

Lisa Lim ◽

Dwight Bibby ◽

Qizhi Fang ◽

...

Keyword(s):

Mitral Valve ◽

Ejection Fraction ◽

Myocardial Fibrosis ◽

Mitral Valve Prolapse ◽

Longitudinal Strain ◽

Global Longitudinal Strain ◽

Left Ventricular ◽

Peak Strain ◽

Mechanical Dispersion ◽

Lv Ejection Fraction

ObjectiveBileaflet mitral valve prolapse (MVP) with either focal or diffuse myocardial fibrosis has been linked to ventricular arrhythmia and/or sudden cardiac arrest. Left ventricular (LV) mechanical dispersion by speckle-tracking echocardiography (STE) is a measure of heterogeneity of ventricular contraction previously associated with myocardial fibrosis. The aim of this study is to determine whether mechanical dispersion can identify MVP at higher arrhythmic risk.MethodsWe identified 32 consecutive arrhythmic MVPs (A-MVP) with a history of complex ventricular ectopy on Holter/event monitor (n=23) or defibrillator placement (n=9) along with 27 MVPs without arrhythmic complications (NA-MVP) and 39 controls. STE was performed to calculate global longitudinal strain (GLS) as the average peak longitudinal strain from an 18-segment LV model and mechanical dispersion as the SD of the time to peak strain of each segment.ResultsMVPs had significantly higher mechanical dispersion compared with controls (52 vs 42 ms, p=0.005) despite similar LV ejection fraction (62% vs 63%, p=0.42) and GLS (−19.7 vs −21, p=0.045). A-MVP and NA-MVP had similar demographics, LV ejection fraction and GLS (all p>0.05). A-MVP had more bileaflet prolapse (69% vs 44%, p=0.031) with a similar degree of mitral regurgitation (mostly trace or mild in both groups) (p>0.05). A-MVP exhibited greater mechanical dispersion when compared with NA-MVP (59 vs 43 ms, p=0.0002). Mechanical dispersion was the only significant predictor of arrhythmic risk on multivariate analysis (OR 1.1, 95% CI 1.02 to 1.11, p=0.006).ConclusionsSTE-derived mechanical dispersion may help identify MVP patients at higher arrhythmic risk.

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