经主动脉流量率与射血分数及每搏指数在低梯度重度主动脉瓣狭窄中的预后价值比较
本研究回顾性纳入475例在Mayo Clinic接受经导管主动脉瓣置换的症状性低梯度重度主动脉瓣狭窄患者，比较经主动脉流量率（TAFR）、左心室射血分数（LVEF）和每搏指数（SVI）对1年全因死亡的预后价值。结果表明，低TAFR（<220 mL/s）独立预测死亡（HR 2.38；95% CI 1.19–4.76，p=0.014），而LVEF和SVI未显示独立关联，提示TAFR可能更准确反映真实血流状态。
要点
- 低TAFR与1年全因死亡独立相关，校正LVEF和SVI后仍显著。
- LVEF<50%和SVI<35 mL/m²在低梯度重度AS中常见，但未独立预测死亡。
- TAFR可能作为评估低梯度重度AS血流状态的更优指标。
核心结论
- 在症状性低梯度重度主动脉瓣狭窄患者中，低经主动脉流量率（TAFR<220 mL/s）而非每搏指数或左心室射血分数，独立与死亡率相关，可能为临床分期提供更准确的血流状态评估。
研究设计与样本
- 回顾性队列研究，纳入2017–2023年在Mayo Clinic接受经导管主动脉瓣置换的低梯度重度主动脉瓣狭窄患者475例（平均年龄85±8岁，49%女性）。
- 低梯度重度主动脉瓣狭窄定义为瓣口面积≤1 cm²且峰值流速<4 m/s或平均压差<40 mm Hg。
- 主要结局为1年全因死亡，采用Kaplan-Meier和Cox比例风险模型分析。
主要发现
- 475例患者中，242例（51%）TAFR<220 mL/s，165例（35%）LVEF<50%，221例（47%）SVI<35 mL/m²。
- 低TAFR与1年死亡率升高显著相关，即使按LVEF或SVI分层后仍存在。
- 多变量分析中，校正低LVEF、低SVI、性别、慢性肾脏病及二尖瓣和三尖瓣反流后，TAFR为死亡的独立预测因子（HR 2.38；95% CI 1.19–4.76，p=0.014）。
关键数值与推荐
- 低梯度重度主动脉瓣狭窄诊断标准：瓣口面积≤1 cm²且峰值流速<4 m/s或平均压差<40 mm Hg。
- 低TAFR定义为<220 mL/s，低SVI定义为<35 mL/m²，低LVEF定义为<50%。
临床怎么用
- 对于症状性低梯度重度主动脉瓣狭窄患者，可考虑计算TAFR以更准确评估血流状态和预后风险。
- TAFR可能辅助识别高危患者，但需进一步研究验证其临床决策价值。
局限性
- 回顾性研究设计，可能存在选择偏倚。
- 单中心或多中心同一医疗系统数据，外推性受限。
- 未报告TAFR测量的一致性及混杂因素控制的详细信息。
以上解读依据论文摘要（全文未开放获取或许可不允许翻译转载）。
原文
BACKGROUND: In low-gradient severe aortic stenosis (AS), reduced left ventricular ejection fraction (LVEF <50%) is practically used to define low flow and prompt dobutamine stress echocardiography to discern pseudo-severe AS. In patients with preserved LVEF, stroke volume index (SVI) <35 mL/m² is typically used. However, both are volume-based surrogates. Transaortic flow rate (TAFR), calculated as stroke volume divided by left ventricular ejection time, may better reflect true flow. Nonetheless, comparative data between TAFR and established metrics remain limited. We aimed to evaluate the prognostic value of TAFR in symptomatic low-gradient severe AS. METHODS: We retrospectively identified patients with low-gradient severe AS (AVA ≤1 cm2 and peak velocity (Vmax) <4 m/s or mean gradient (MG) <40 mm Hg) who underwent transcatheter aortic valve replacement at Mayo Clinic sites (2017-2023). The primary outcome was 1-year all-cause mortality. Survival was assessed using Kaplan-Meier and Cox proportional hazards models. RESULTS: Among 475 patients included (mean age 85±8 years; 49% women), 242 (51%) had TAFR <220 mL/s, 165 (35%) had EF <50%, and 221 (47%) had SVI <35 mL/m2. Low TAFR was significantly associated with higher 1-year mortality even after stratifying by EF or SVI. In multivariate analysis, TAFR was an independent predictor of mortality (HR 2.38; 95% CI 1.19 to 4.76, p=0.014) after adjusting for reduced LVEF, low SVI, gender, chronic kidney disease and mitral and tricuspid regurgitation. CONCLUSIONS: In patients with symptomatic low-gradient severe AS, low TAFR, not SVI or LVEF, is independently associated with mortality and may offer more accurate measure of flow state for clinical staging.
引用
- Allam M, Villa Etchegoyen C, Alsidawi S, et al. Prognostic value of transaortic flow rate compared with ejection fraction and stroke volume index in low-gradient severe aortic stenosis. Heart. 2026. PMID: 41980805. doi:10.1136/heartjnl-2025-327594
供执业医师工作参考，不替代临床判断；数值与分级以指南原文为准。