AimsThis study aims to assess the applicability of the mitral regurgitation (MR) proportionality concept in patients with atrial functional mitral regurgitation (aFMR) treated with transcatheter edge‐to‐edge repair (M‐TEER). We hypothesized that patients with disproportionate MR (higher MR relative to left ventricular size) would exhibit different outcomes compared to those with proportionate MR, despite undergoing M‐TEER.Methods and resultsWe retrospectively analysed 98 patients with aFMR from the EuroSMR registry who underwent M‐TEER between 2008 and 2019. Patients met criteria for aFMR (normal indexed left ventricular end‐diastolic volume [LVEDV], preserved left ventricular ejection fraction [LVEF] ≥ 50% without regional wall motion abnormalities, and structurally normal mitral valves). We excluded patients with missing effective regurgitant orifice area (EROA) or LVEDV data. The primary endpoint was 2‐year mortality, with an EROA/LVEDV ratio employed to differentiate disproportionate from proportionate MR. Procedural success and baseline characteristics were analysed, and multivariate Cox proportional hazards models were used to identify mortality predictors. The mean patient age was 79 ± 7.3 years, with 68.8% female, and 79% had a history of atrial fibrillation. The mean EROA was 0.27 ± 0.14 cm2, and LVEDV was 95.6 ± 33.7 mL. Disproportionate MR was identified with an EROA/LVEDV ratio >0.339 cm2/100 mL. While procedural success was similar in both groups, disproportionate MR was associated with a numerically higher estimate of systolic pulmonary artery pressures (sPAP) and rates of NYHA ≥III and TR ≥ 3+. Disproportionate MR had a significant association with increased 2‐year mortality (P < 0.001). The EROA/LVEDV ratio and tricuspid annular plane systolic excursion (TAPSE) were independent predictors of 2‐year mortality (EROA/LVEDV: HR: 1.35, P = 0.010; TAPSE: HR: 0.85, P = 0.020).ConclusionsThis analysis introduces the MR proportionality concept in aFMR patients and its potential prognostic value. Paradoxically, disproportionate MR in aFMR was linked to a 1.35‐fold increase in 2‐year mortality post‐M‐TEER, emphasizing the importance of accurate preprocedural FMR characterization. Our findings in patients with disproportionate MR indicate that a high degree of aFMR with high regurgitant volumes may lead to aggravated symptoms, which is a known contributor to increased mortality following M‐TEER. These results underline the need for further research into the pathophysiology of aFMR to inform potential preventative and therapeutic strategies, ensuring optimal patient outcomes.

中文翻译：

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不成比例的心房功能性二尖瓣反流与经导管边对边修复后生存的悖论

目的本研究旨在评估二尖瓣反流 (MR) 比例概念在接受经导管边对边修复术 (M-TEER) 治疗的心房功能性二尖瓣反流 (aFMR) 患者中的适用性。我们假设，尽管接受了 M-TEER，但不成比例 MR（相对于左心室大小的 MR 更高）的患者与比例 MR 的患者相比，会表现出不同的结果。方法和结果我们回顾性分析了 EuroSMR 登记处接受 M-TEER 的 98 名 aFMR 患者。 2008 年至 2019 年间的 TEER。患者符合 aFMR 标准（左心室舒张末期指数正常，左心室射血分数保留 [LVEF] ≥ 50%，无局部室壁运动异常，二尖瓣结构正常）。我们排除了缺少有效反流口面积 (EROA) 或 LVEDV 数据的患者。主要终点是 2 年死亡率，采用 EROA/LVEDV 比值来区分不成比例的 MR 和成比例的 MR。分析了手术成功和基线特征，并使用多变量 Cox 比例风险模型来确定死亡率预测因子。患者平均年龄为 79 ± 7.3 岁，其中 68.8% 为女性，79% 有房颤病史。平均 EROA 为 0.27 ± 0.14 cm2，LVEDV 为 95.6 ± 33.7 mL。 EROA/LVEDV 比值 >0.339 cm 即可确定不成比例的 MR2/100 毫升。虽然两组的手术成功率相似，但不成比例的 MR 与收缩期肺动脉压 (sPAP) 的数值较高估计值以及 NYHA ≥ III 和 TR ≥ 3+ 的比率相关。不成比例的 MR 与 2 年死亡率增加显着相关（磷< 0.001）。 EROA/LVEDV 比值和三尖瓣环平面收缩期偏移 (TAPSE) 是 2 年死亡率的独立预测因子（EROA/LVEDV：HR：1.35，磷= 0.010；塔普斯：HR：0.85，磷= 0.020）。结论该分析介绍了 aFMR 患者的 MR 比例概念及其潜在的预后价值。矛盾的是，aFMR 中不成比例的 MR 与 M-TEER 后 2 年死亡率增加 1.35 倍相关，这强调了准确的术前 FMR 表征的重要性。我们对不成比例 MR 患者的研究结果表明，高度 aFMR 和高反流量可能会导致症状加重，这是 M-TEER 后死亡率增加的已知原因。这些结果强调需要进一步研究 aFMR 的病理生理学，以告知潜在的预防和治疗策略，确保最佳的患者治疗结果。