OBJECTIVES This study aimed to assess the value of low transvalvular flow rate (FR) for the prediction of mortality compared with low stroke volume index (SVi) in patients with low-gradient (mean gradient: <40 mm Hg), low aortic valve area (<1 cm2) aortic stenosis (AS) following aortic valve intervention. BACKGROUND Transaortic FR defined as stroke volume/left ventricular ejection time is also a marker of flow; however, no data exist comparing the relative prognostic value of these 2 transvalvular flow markers in patients with low-gradient AS who had undergone valve intervention. METHODS We retrospectively followed prospectively assessed consecutive patients with low-gradient, low aortic valve area AS who underwent aortic valve intervention between 2010 and 2014 for all-cause mortality. RESULTS Of the 218 patients with mean age 75 ± 12 years, 102 (46.8%) had low stroke volume index (SVi) (<35 ml/m2), 95 (43.6%) had low FR (<200 ml/s), and 58 (26.6%) had low left ventricular ejection fraction <50%. The concordance between FR and SVi was 78.8% (p < 0.005). Over a median follow-up of 46.8 ± 21 months, 52 (23.9%) deaths occurred. Patients with low FR had significantly worse outcome compared with those with normal FR (p < 0.005). In patients with low SVi, a low FR conferred a worse outcome than a normal FR (p = 0.005), but FR status did not discriminate outcome in patients with normal SVi. By contrast, SVi did not discriminate survival either in patients with normal or low FR. Low FR was an independent predictor of mortality (p = 0.013) after adjusting for age, clinical prognostic factors, European System for Cardiac Operative Risk Evaluation II, dimensionless velocity index, left ventricular mass index, left ventricular ejection fraction, heart rate, time, type of aortic valve intervention, and SVi (p = 0.59). CONCLUSIONS In patients with low-gradient, low valve area aortic stenosis undergoing aortic valve intervention, low FR, not low SVi, was an independent predictor of medium-term mortality.

中文翻译：

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低瓣膜血流速度可预测主动脉瓣介入术后低梯度主动脉瓣狭窄患者的死亡率。

目的本研究旨在评估低梯度（平均梯度：<40 mm Hg），低主动脉瓣膜病患者低经瓣膜流速（FR）与低卒中体积指数（SVi）相比的死亡率预测价值主动脉瓣介入治疗后（<1 cm2）主动脉瓣狭窄（AS）。背景技术定义为中风量/左心室射血时间的经主动脉FR也是血流的标志。但是，尚无数据比较这两种经瓣膜血流指标在接受瓣膜干预的低梯度AS患者中的相对预后价值。方法我们回顾性评估了2010年至2014年间接受主动脉瓣膜介入治疗的低梯度，低主动脉瓣膜区域AS连续患者的全因死亡率。结果在218名平均年龄为75±12岁的患者中，有102名（46.8％）的低卒中体积指数（SVi）（<35 ml / m2），95名（43.6％）的FR低（<200 ml / s）， 58例（26.6％）的左心室射血分数低（<50％）。FR和SVi之间的一致性为78.8％（p <0.005）。在46.8±21个月的中位随访中，有52例（23.9％）死亡。与正常FR患者相比，低FR患者的预后明显更差（p <0.005）。SVi较低的患者，FR低于正常FR（p = 0.005），但FR状态不能区分SVi正常的患者。相比之下，SVi不能区分正常或低FR患者的生存率。调整年龄，临床预后因素后，低FR是死亡率的独立预测因子（p = 0.013），欧洲心脏手术风险评估系统II，无量纲速度指数，左心室质量指数，左心室射血分数，心率，时间，主动脉瓣膜干预类型和SVi（p = 0.59）。结论在接受主动脉瓣膜介入治疗的低梯度，低瓣膜区主动脉瓣狭窄患者中，低FR而不是SVi低是中期死亡率的独立预测因子。