Magne Julien, Mohty Dania, Boulogne Cyrille, Deltreuil Mathieu, Cassat Claude, Echahidi Najmeddine, Laskar Marc, Lacroix Philippe, Virot Patrice, Aboyans Victor
CHU Limoges, Hôpital Dupuytren, Service Cardiologie, Limoges, F-87042, France; INSERM 1094, Faculté de médecine de Limoges, 2, rue Marcland, 87000 Limoges, France; CHU Limoges, Hôpital Dupuytren, Service de Chirurgie Thoracique et Cardiovasculaire, Limoges F-87042, France.
CHU Limoges, Hôpital Dupuytren, Service Cardiologie, Limoges, F-87042, France; INSERM 1094, Faculté de médecine de Limoges, 2, rue Marcland, 87000 Limoges, France; CHU Limoges, Hôpital Dupuytren, Service de Chirurgie Thoracique et Cardiovasculaire, Limoges F-87042, France.
Int J Cardiol. 2015 Feb 1;180:158-64. doi: 10.1016/j.ijcard.2014.11.180. Epub 2014 Nov 26.
Global left ventricular (LV) afterload as assessed by valvulo-arterial impedance (Zva), may be an independent predictor of mortality in patients with severe aortic stenosis (AS) and preserved LV ejection fraction (LVEF). However, its quantification using echocardiography may be subject to error measurement. We aimed to determine the prevalence and impact on long-term survival of high Zva, purposely measured by cardiac catheterization.
676 patients with preserved LVEF and severe AS without other valvular heart diseases underwent cardiac catheterization. Zva was derived from catheterization and calculated as follows: mean aortic gradient+systolic blood pressure/indexed LV stroke volume. Zva was considered high when >5mmHg/mL/m(2) based on previous studies. Overall, high Zva was found in 42% of all AS patients. Four-year survival and 8-year survival were significantly reduced in patients with high Zva (74±3% and 57±4%) as compared to those with low Zva (85±2% and 74±3%; p=0.002). After adjustment for all other risk factors, Zva was independently associated with reduced long-term survival (hazard ratio [HR]=1.47 95% CI: 1.04-2.09; p=0.029). Of interest, high Zva remained associated with reduced survival as compared to low Zva, in patients with normal LV stroke volume, but was no longer significant in low flow patients (p=0.98).
High Zva, estimated invasively in our study, is frequent in patients with severe AS, and appears as a robust and independent predictor of survival. Zva should be used as an additional parameter for risk stratification of severe AS, more particularly in patients with normal flow.
通过瓣膜 - 动脉阻抗（Zva）评估的整体左心室（LV）后负荷，可能是重度主动脉瓣狭窄（AS）且左心室射血分数（LVEF）保留患者死亡率的独立预测指标。然而，使用超声心动图对其进行量化可能存在测量误差。我们旨在确定通过心导管检查特意测量的高Zva的患病率及其对长期生存的影响。
676例LVEF保留且患有重度AS且无其他瓣膜性心脏病的患者接受了心导管检查。Zva通过导管检查得出，计算方法如下：平均主动脉瓣压差 + 收缩压/左心室每搏量指数。根据先前研究，当Zva > 5mmHg/mL/m²时被认为是高值。总体而言，所有AS患者中有42%发现高Zva。高Zva患者的4年生存率和8年生存率（分别为74±3%和57±4%）与低Zva患者（分别为85±2%和74±3%；p = 0.002）相比显著降低。在对所有其他危险因素进行调整后，Zva与长期生存率降低独立相关（风险比[HR] = 1.47，95%置信区间：1.04 - 2.09；p = 0.029）。有趣的是，与低Zva相比，左心室每搏量正常的患者中高Zva仍与生存率降低相关，但在低流量患者中不再显著（p = 0.98）。
在我们的研究中通过侵入性方法估计的高Zva在重度AS患者中很常见，并且似乎是生存的有力且独立的预测指标。Zva应作为重度AS风险分层的附加参数，尤其是在流量正常的患者中。
