Department of Medicine, Division of Cardiology, University of California, San Francisco.
Circ Cardiovasc Imaging. 2024 Jun;17(6):e016319. doi: 10.1161/CIRCIMAGING.123.016319. Epub 2024 Jun 11.
Prominent multi-scallop systolic leaflet displacement toward the left atrium (atrialization) is typically observed in bileaflet mitral valve prolapse (MVP) with mitral annular disjunction. We hypothesized that mitral leaflet atrialization is associated with an underlying left atrial (LA) myopathy characterized by progressive structural and functional abnormalities, irrespective of mitral regurgitation (MR) severity.
We identified 334 consecutive patients with MVP, no prior atrial fibrillation, and comprehensive clinical and echocardiographic data. LA function was assessed by LA reservoir strain, LA function index, and LA emptying fraction. We also classified the stage of LA remodeling based on LA enlargement and LA reservoir strain (stage 1: no remodeling; stage 2: mild remodeling; stage 3: moderate remodeling; and stage 4: severe remodeling). The primary end point was the composite risk of sudden arrhythmic death, heart failure hospitalization, or the new onset of atrial fibrillation.
Bileaflet MVP with no or mild MR had a lower LA reservoir strain (=0.04) and LA function index (<0.001) compared with other MVP subtypes. In multivariable linear regression adjusted for cardiovascular risk factors and MR ≥moderate, bileaflet MVP remained significantly associated with lower LA function parameters (all <0.05). There was a significant increase in the risk of events as the LA reservoir strain and LA remodeling stage increased (<0.001). In multivariable analysis, stage 4 of LA remodeling remained significantly associated with a higher risk of events compared with stage 1 (hazard ratio, 6.09 [95% CI, 1.69-21.9]; =0.006).
In a large MVP registry, bileaflet involvement is associated with reduced LA function regardless of MR severity, suggesting a primary atriopathy in this MVP subtype. Abnormal LA function, particularly when assessed through a multiparametric approach, is linked to a higher risk of cardiovascular events and may improve risk stratification in MVP, even in those without significant MR.
在二尖瓣瓣叶脱垂（MVP）伴二尖瓣环分离的情况下，通常会观察到多瓣叶收缩期瓣叶向左心房（心房化）的明显移位。我们假设，二尖瓣瓣叶心房化与潜在的左心房（LA）心肌病有关，其特征为进行性的结构和功能异常，而与二尖瓣反流（MR）的严重程度无关。
我们确定了 334 例连续的 MVP 患者，这些患者没有先前的心房颤动，并且具有全面的临床和超声心动图数据。通过左心房储备应变、左心房功能指数和左心房排空分数来评估左心房功能。我们还根据左心房扩大和左心房储备应变对左心房重构阶段进行分类（阶段 1：无重构；阶段 2：轻度重构；阶段 3：中度重构；阶段 4：重度重构）。主要终点是心律失常性死亡、心力衰竭住院或新发心房颤动的复合风险。
与其他 MVP 亚型相比，无或轻度 MR 的双瓣叶 MVP 的左心房储备应变（=0.04）和左心房功能指数（<0.001）较低。在调整心血管危险因素和 MR≥中度的多变量线性回归中，双瓣叶 MVP 仍然与较低的左心房功能参数显著相关（均<0.05）。随着左心房储备应变和左心房重构阶段的增加，事件风险显著增加（<0.001）。在多变量分析中，与阶段 1 相比，左心房重构的阶段 4 与更高的事件风险显著相关（危险比，6.09[95%CI，1.69-21.9]；=0.006）。
在一个大型 MVP 登记处，双瓣叶受累与 LA 功能降低有关，无论 MR 严重程度如何，这表明在这种 MVP 亚型中存在原发性心房病。异常的 LA 功能，特别是通过多参数方法评估时，与心血管事件的更高风险相关，即使在那些没有明显 MR 的 MVP 患者中，也可能改善 MVP 的风险分层。
