Université de Nantes, CHU de Nantes, CNRS, INSERM, l'institut du thorax, France (A.-L.C.D.B., C.C., S.L.S., R.C., A.T., C.T., J.-B.G., J.-N.T., J.-J.S., J.-C.R., J.-M. Serfaty, T.L.T.).
Service de Cardiologie, Institut Lorrain du Cœur et des Vaisseaux, CHU de Nancy, France (O.H., L.F., C.V., D.M., J.-M. Sellal, P.-Y.M., C.S.-S.).
Circulation. 2021 May 4;143(18):1763-1774. doi: 10.1161/CIRCULATIONAHA.120.050214. Epub 2021 Mar 12.
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 in patients with MVP.
Four hundred patients (53±15 years of age, 55% male) with MVP (trace to severe MR by echocardiography) from 2 centers, who underwent a comprehensive echocardiography and LGE cardiac magnetic resonance, 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).
Replacement myocardial fibrosis (LGE+) was observed in 110 patients (28%; 91 with myocardial wall including 71 with basal inferolateral wall, 29 with papillary muscle). LGE+ prevalence was 13% in trace-mild MR, 28% in moderate MR, and 37% in severe MR, and was associated with specific features of mitral valve apparatus, more dilated LV and more frequent ventricular arrhythmias (45% versus 26%, <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 (odds ratio, 1.01 [95% CI, 1.002-1.017], =0.009) and moderate-severe MR (odds ratio, 2.28 [95% CI, 1.21-4.31], =0.011). LGE+ was associated with worse 4-year cardiovascular event-free survival (49.6±11.7 in LGE+ versus 73.3±6.5% in LGE-, <0.0001). In a stepwise multivariable Cox model, MR volume and LGE+ (hazard ratio, 2.6 [1.4-4.9], =0.002) were associated with poor outcome.
LV replacement myocardial fibrosis is frequent in patients with MVP; is associated with mitral valve apparatus alteration, more dilated LV, MR grade, and ventricular arrhythmia; and is independently associated with cardiovascular events. These findings suggest an MVP-related myocardial disease. Last, cardiac magnetic resonance provides additional information to echocardiography in MVP.
二尖瓣脱垂（MVP）是一种常见疾病，可并发二尖瓣反流（MR）、心力衰竭、动脉栓塞、节律障碍和死亡。左心室（LV）替代心肌纤维化是 MVP 患者适应性重构的标志物，但这一发现的意义仍知之甚少。我们旨在通过心脏磁共振的晚期钆增强（LGE）评估 MVP 患者 LV 替代心肌纤维化的患病率、病理生理和预后意义。
来自 2 个中心的 400 名 MVP 患者（53±15 岁，55%为男性），接受了全面的超声心动图和 LGE 心脏磁共振检查。评估了替代心肌纤维化（LGE+）的相关性、MR 程度的影响和室性心律失常。主要结局是心血管事件（心源性死亡、心力衰竭、新发心房颤动、动脉栓塞和危及生命的室性心律失常）的复合事件。
110 名患者（28%；91 名患者有心肌壁，其中 71 名患者有基底下外侧壁，29 名患者有乳头肌）出现替代心肌纤维化（LGE+）。微量-轻度 MR 中的 LGE+患病率为 13%，中度 MR 为 28%，重度 MR 为 37%，与二尖瓣装置的特定特征、更大的 LV 扩张和更频繁的室性心律失常相关（45% vs 26%，<0.0001）。在微量-轻度 MR 中，尽管没有明显的容量超负荷，但仍有 16%的患者存在异常的 LV 扩张，25%的患者存在室性心律失常。多变量分析的 LGE+相关因素为 LV 质量（比值比，1.01[95%可信区间，1.002-1.017]，=0.009）和中度-重度 MR（比值比，2.28[95%可信区间，1.21-4.31]，=0.011）。LGE+与 4 年心血管事件无事件生存率较差相关（LGE+为 49.6±11.7%，LGE-为 73.3±6.5%，<0.0001）。在逐步多变量 Cox 模型中，MR 容积和 LGE+（风险比，2.6[1.4-4.9]，=0.002）与不良预后相关。
MVP 患者中 LV 替代心肌纤维化较为常见；与二尖瓣装置改变、更大的 LV、MR 分级和室性心律失常相关；并与心血管事件独立相关。这些发现提示 MVP 相关的心肌疾病。最后，心脏磁共振为 MVP 提供了超声心动图之外的附加信息。
