武汉云克隆科技股份有限公司

Abstract

AIMS:

We reported that patients with small aortic valve area (AVA) and low flow despite preserved left ventricular ejection fraction (LVEF), i.e. 'paradoxical' low flow (PLF), have worse outcomes compared with patients with normal flow (NF), although they generally have a lower mean gradient (MG). The aortic valve weight (AVW) excised at the time of valve replacement is a flow-independent marker of stenosis severity. The objective of this study was to compare the AVW of patients with PLF and MG<40 mmHg with the AVW of patients with NF and MG≥40 mmHg.

METHODS AND RESULTS:

We recruited 250 consecutive patients undergoing valve replacement (Cohort A) for severe stenosis. Among them, 33 (13%) were in PLF [LVEF > 50% but stroke volume index (SVi) ≤ 35 mL/m²] with MG < 40 mmHg (PLF-LG group) and 105 (42%) were in NF (LVEF > 50% and SVi > 35 mL/m²) with MG ≥ 40 mmHg (NF-HG group). Despite a much lower MG (29 ± 7 vs. 53 ± 10 mmHg; P < 0.0001), patients in the PLF-LG group had a similar AVA (0.73 ± 0.12 vs. 0.69 ± 0.13; P = 0.19) compared with those in the NF-HG group. The AVW [median (interquartile): 1.90 (1.63-2.50) vs. 2.60 (1.66-3.32)] and prevalence of bicuspid phenotype (15 vs. 42%) were lower in the PLF-LG group than in the NF-HG group. However, AVWs analysed separately in the tricuspid and bicuspid valves were similar in both groups [tricuspid valves: 1.80 (1.63-2.50) vs. 2.30 (1.58-3.00) g; P = 0.26 and bicuspid valves: 2.72 (1.73-3.61) vs. 2.60 (2.10-3.55) g; P = 0.93]. When using cut-point values of AVW established in another series of non-consecutive patients (n = 150, Cohort B) with NF and concordant Doppler-echocardiographic findings, we found that the percentage of patients with evidence of severe stenosis in Cohort A was 70% in patients with PLF-LG and 86% in patients with NF-HG.

CONCLUSION:

The aortic valve weight data reported in this study provide evidence that a large proportion of patients with PLF and low-gradient have a severe stenosis and that the gradient may substantially underestimate stenosis severity in these patients. A multi-parametric approach including all Doppler-echocardiographic parameters of valve function as well as other complementary diagnostic tests may help correctly identify these patients.

摘要

目的：

尽管左心室射血分数（LVEF）保持不变，小主动脉瓣区（AVA）和低流量的患者，如“反常的”低流量（PLF）患者与正常血流（NF）患者相比，结果更差，尽管它们通常有较低的平均梯度（MG）。在瓣膜置换术时切除的主动脉瓣重量（AVW）是狭窄严重性的一种血流量独立的标志物。本研究的目的是比较异常低血流量和平均梯度<40 mmHg患者与正常血流和平均梯度≥40 mmHg患者的主动脉瓣重量。

方法和结果：

我们招募了250名接受瓣膜置换术（A组）连续发病的患者，以治疗严重的狭窄。其中，33名患者（13%）表现异常低血流量[左心室射血分数>50%，但是心搏容量指数（SVi）≤ 35 ml/m²]并且平均梯度<40 mmHg（PLF-LG组），105名患者（42%）表现正常血流（左心室射血分数>50%，心搏容量指数>35 ml/m²）并且平均梯度 40 mmHg（NF-HG组）。尽管PLF-LG组的患者与NF-HG组的患者相比，有很低的平均梯度（29 ± 7和53 ± 10 mmHg；P < 0.0001），小主动脉瓣区（0.73 ± 0.12和0.69 ± 0.13；P = 0.19）是差不多的。主动脉瓣重量[中值（四分位距）：1.90（1.63-2.50）和2.60（1.66-3.32）]和双尖型的患病率（15%和42%）在PLF-LG组中低于NF-HG组。然而，在三尖瓣和双尖瓣中分别分析主动脉瓣重量，这两组结果相似[三尖瓣：1.80（1.63-2.50）和2.30（1.58-3.00）g，P=0.26；双尖瓣：2.72（1.73-3.61）和2.60（2.10-3.55）g，P = 0.93]。当在另一系列表现正常血流量的非连续发病的患者（n = 150，B组）中使用主动脉瓣重量的分割点和整合多普勒彩超结果，我们发现A组中有严重狭窄症状的患者，PLF-LG组为70%， NF-HG组为86%。

结论：

在这项研究报告中的主动脉瓣重量数据表明，有异常低血流量和低梯度的患者大部分有严重的狭窄症状，而且梯度可能大大低估了这些患者的狭窄程度。一种多参数的方法，包括所有的多普勒超声心动图参数以及其他补充诊断检测，可能有助于正确鉴定这些患者。

使用试剂原文信息：Blood samples were drawn before surgery and plasma NT pro-BNP was determined by a commercially available enzyme-linked immunosorbent assay (USCN Life Science Inc., Wuhan, China). Creatinine was also measured.