The natural history of moderate/severe atrial functional mitral regurgitation (AFMR) is unknown. The authors sought to study the incidence of left ventricular (LV) systolic dysfunction (LVSD), progression or regression of ≥mild-moderate AFMR, and impact on mortality. Adults with left atrial (LA) volume index ≥40 mL/m, ≥mild-moderate AFMR, and follow-up echocardiogram were followed for incident LVSD (ejection fraction <50% and ≥10% lower than baseline), progression of mild-moderate/moderate AFMR to severe, and persistent regression of AFMR to no/trivial. Relation of AFMR progression or regression as time-dependent covariates with all-cause mortality was studied. Incidence of LVSD was compared with patients with no/mild AFMR matched on age, sex, comorbidities and ejection fraction. Patients were followed until mitral intervention, myocardial infarction, or last follow-up. A total of 635 patients (median age 75 years, 51% female, 96% mild-moderate/moderate AFMR, 4% severe AFMR) were included. Over a median 2.2 years (Q1-Q3: 1.0-4.3 years), incidence rates per 100 person-years were 3.2 for LVSD ( = 0.52 vs patients with no/mild AFMR), 1.9 for progression of AFMR, and 3.9 for regression. Female sex and larger LA volume index were independently associated with progression, whereas younger age, male sex, absent atrial fibrillation, and higher LA emptying fraction were independently associated with regression. Neither AFMR progression nor regression was independently associated with mortality. Instead, independent risk factors for mortality included older age, concentric LV geometry, and higher estimated LV filling and pulmonary pressures. In patients with predominantly mild-moderate/moderate AFMR, regression of MR was more common than progression, but neither was associated with mortality. Instead, diastolic function abnormalities were more important. Over a median 2-year follow-up, LVSD risk was not increased.

中文翻译：

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心房功能性二尖瓣反流的自然史

中度/重度心房功能性二尖瓣反流 (AFMR) 的自然史尚不清楚。作者试图研究左心室 (LV) 收缩功能障碍 (LVSD) 的发生率、≥轻中度 AFMR 的进展或消退以及对死亡率的影响。对左心房 (LA) 容积指数≥40 mL/m、≥轻中度 AFMR 和随访超声心动图的成人进行随访，了解发生 LVSD（射血分数 <50% 且低于基线 ≥10%）、轻度-中度进展的情况。中度/中度 AFMR 至严重，以及 AFMR 持续退化至无/轻微。研究了 AFMR 进展或回归作为时间依赖性协变量与全因死亡率的关系。将 LVSD 的发生率与年龄、性别、合并症和射血分数匹配的无/轻度 AFMR 患者进行比较。对患者进行随访直至二尖瓣介入治疗、心肌梗死或最后一次随访。共有 635 名患者（中位年龄 75 岁，51% 为女性，96% 为轻度-中度/中度 AFMR，4% 为重度 AFMR）纳入研究。在中位 2.2 年（第一季度至第三季度：1.0-4.3 年）中，每 100 人年的 LVSD 发病率为 3.2（与无/轻度 AFMR 患者相比 = 0.52），AFMR 进展为 1.9，回归为 3.9。女性和较大的 LA 容量指数与进展独立相关，而年龄较小、男性、无房颤和较高的 LA 排空分数与回归独立相关。 AFMR 进展或消退均与死亡率无关。相反，死亡的独立危险因素包括年龄较大、左心室同心几何形状以及估计的左心室充盈度和肺动脉压较高。在以轻度-中度/中度 AFMR 为主的患者中，MR 消退比进展更常见，但两者均与死亡率无关。相反，舒张功能异常更为重要。在中位 2 年随访中，LVSD 风险并未增加。