Guazzi Marco, Myers Jonathan, Arena Ross
Cardiopulmonary Laboratory, University of Milan, San Paolo Hospital, Milan, Italy.
J Am Coll Cardiol. 2005 Nov 15;46(10):1883-90. doi: 10.1016/j.jacc.2005.07.051. Epub 2005 Oct 24.
This study sought to define the relative prognostic value of cardiopulmonary exercise testing (CPET) variables in heart failure (HF) patients with preserved versus reduced systolic function.
Cardiopulmonary exercise testing has an established role in the assessment of patients with systolic heart failure (SHF). Two variables, peak Vo2 and, more recently, the VE/VCO2 slope, have been shown to be extremely valuable in risk stratification. However, data are lacking in terms of the prognostic value of CPET in patients with diastolic heart failure (DHF).
A total of 409 HF patients underwent CPET. Patients were divided into three groups according to the following left ventricular ejection fraction (LVEF) cutoffs: > or =40%, > or =45%, and > or =50%. The CPET response and the ability of peak VO2 and the VE/VCO2 slope to predict total mortality and hospitalization were examined.
At univariate Cox regression analysis, both the peak VO2 and the VE/VCO2 slope were significant predictors in SHF and DHF. Multivariate analysis documented a similar prognostic power of VE/VCO2 slope and peak VO2 in all SHF groups. Conversely, in DHF patients, VE/VCO2 slope outnumbered peak VO2, remaining the only predictor regardless of LVEF. In DHF, the area under the receiver operating characteristic curve for the VE/VCO2slope identified a cutoff of 32.6 (74% sensitivity, 52% specificity), 33.1 (76% sensitivity, 62% specificity), and 33.3 (97% sensitivity, 40% specificity) for an LVEF cutoff of > or =40%, > or =45%, and > or =50%, respectively.
These results extend the clinical and prognostic applicability of CPET to DHF. An impairment in exercise ventilation rather than peak VO2 holds clinical and prognostic impact in this increasing subset of patients.
本研究旨在明确心肺运动试验（CPET）变量在收缩功能保留与降低的心力衰竭（HF）患者中的相对预后价值。
心肺运动试验在收缩性心力衰竭（SHF）患者评估中具有既定作用。两个变量，即峰值摄氧量（peak Vo2）以及最近提出的每分钟通气量与二氧化碳排出量比值（VE/VCO2）斜率，已被证明在风险分层中极具价值。然而，关于CPET在舒张性心力衰竭（DHF）患者中的预后价值的数据尚缺。
共有409例HF患者接受了CPET。根据以下左心室射血分数（LVEF）临界值将患者分为三组：≥40%、≥45%和≥50%。对CPET反应以及peak VO2和VE/VCO2斜率预测全因死亡率和住院率的能力进行了检查。
在单因素Cox回归分析中，peak VO2和VE/VCO2斜率在SHF和DHF中均为显著预测因子。多因素分析表明，在所有SHF组中，VE/VCO2斜率和peak VO2具有相似的预后能力。相反，在DHF患者中，VE/VCO2斜率比peak VO2更具优势，无论LVEF如何，它都是唯一的预测因子。在DHF中，对于LVEF临界值≥40%、≥45%和≥50%，VE/VCO2斜率的受试者工作特征曲线下面积分别确定的临界值为32.6（敏感性74%，特异性52%）、33.1（敏感性76%，特异性62%）和33.3（敏感性97%，特异性40%）。
这些结果扩展了CPET在DHF中的临床和预后适用性。在这一不断增加的患者亚组中，运动通气受损而非peak VO2具有临床和预后影响。
