Dahan Shani, Dal-Bianco Jacob, Plakht Ygal, Namasivayam Mayooran, Capoulade Romain, Zeng Xin, Passeri Jonathan J, Yucel Evin, Picard Michael H, Levine Robert A, Hung Judy
medRxiv. 2024 Sep 22:2024.09.19.24314018. doi: 10.1101/2024.09.19.24314018.
Patients with paradoxical low-flow, low-gradient severe aortic stenosis (LFLGAS) exhibit low transvalvular flow rate (Q), while maintaining preserved left ventricular ejection fraction (LVEF). Concomitant severe mitral regurgitation (MR) contributes to the low flow state, adding complexity to diagnosis and management. This study aimed to examine the impact of severe MR on outcomes in paradoxical LFLGAS.
Data from an institutional echo database identified 1,189 patients with adjudicated severe aortic stenosis (AVA≤1.0 cm ), low transaortic gradients (mean gradient<40 mmHg), preserved LVEF (≥50%), and low flow rate (Q≤210 ml/sec), to confirm paradoxical LFLGAS. Subgroups were based on MR severity (severe and non-severe). Clinical outcomes included all-cause mortality, aortic valve replacement (AVR), heart failure hospitalizations, and a composite outcome.
In the severe MR group (n=80), patients had lower flow rates, increased LV dimensions and a more eccentric hypertrophy pattern compared to non-severe MR (n=1,109). Over a median 5-year follow-up, severe MR correlated with higher all-cause mortality (p=0.02) and AVR rates (p=0.012). After adjustment, severe MR was independently associated with increased all-cause mortality risk (HR=1.43, p=0.011) and composite outcome (HR=1.64, p<0.001). AVR significantly reduced mortality at every MR degree, with the most substantial impact in severe MR (HR=0.18, p<0.001). Propensity-adjusted models demonstrated a stronger AVR impact with increasing MR degree (p-for-interaction=0.044).
Severe MR in paradoxical LFLGAS is associated with adverse outcomes and distinctive LV remodeling. Aortic valve replacement improves survival across all MR grades, with greater impact in severe MR.
矛盾性低流量、低梯度严重主动脉瓣狭窄（LFLGAS）患者表现为跨瓣血流量（Q）较低，同时左心室射血分数（LVEF）保持正常。合并严重二尖瓣反流（MR）会导致低流量状态，增加诊断和管理的复杂性。本研究旨在探讨严重MR对矛盾性LFLGAS患者预后的影响。
从机构超声心动图数据库中获取数据，确定1189例经判定为严重主动脉瓣狭窄（主动脉瓣口面积≤1.0 cm ）、低跨主动脉梯度（平均梯度<40 mmHg）、LVEF正常（≥50%）且血流量较低（Q≤210 ml/秒）的患者，以确诊矛盾性LFLGAS。根据MR严重程度分为亚组（严重和非严重）。临床结局包括全因死亡率、主动脉瓣置换术（AVR）、心力衰竭住院率和复合结局。
与非严重MR组（n = 1109）相比，严重MR组（n = 80）患者的血流量较低，左心室尺寸增大，且左心室肥厚模式更偏心。在中位5年随访期内，严重MR与较高的全因死亡率（p = 0.02）和AVR率（p = 0.012）相关。调整后，严重MR与全因死亡风险增加（HR = 1.43，p = 0.011）和复合结局（HR = 1.64，p < 0.001）独立相关。AVR在各个MR程度下均显著降低死亡率，对严重MR的影响最大（HR = 0.18，p < 0.001）。倾向调整模型显示，随着MR程度增加，AVR的影响更强（交互作用p值 = 0.044）。
矛盾性LFLGAS中的严重MR与不良结局和独特的左心室重构相关。主动脉瓣置换术可改善所有MR分级患者的生存率，对严重MR患者的影响更大。
