Buys Roselien, Coeckelberghs Ellen, Cornelissen Véronique A, Goetschalckx Kaatje, Vanhees Luc
Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium.
Eur J Prev Cardiol. 2016 Sep;23(13):1363-71. doi: 10.1177/2047487316643446. Epub 2016 Apr 20.
Peak oxygen uptake is an independent predictor of mortality in patients with coronary artery disease (CAD). However, patients with CAD are not always capable of reaching peak effort, and therefore submaximal gas exchange variables such as the oxygen uptake efficiency slope (OUES) have been introduced. Baseline exercise capacity as expressed by OUES provides prognostic information and this parameter responds to training. Therefore, we aimed to assess the prognostic value of post-training OUES in patients with CAD.
We included 960 patients with CAD (age 60.6 ± 9.5 years; 853 males) who completed a cardiac rehabilitation program between 2000 and 2011. The OUES was calculated before and after cardiac rehabilitation and information on mortality was obtained. The relationships of post-training OUES with all-cause and cardiovascular (CV) mortality was assessed by Cox proportional hazards regression analyses. Receiver operator characteristic curve analysis was performed in order to obtain the optimal cut-off value.
During 7.37 ± 3.20 years of follow-up (range: 0.45-13.75 years), 108 patients died, among whom 47 died due to CV reasons. The post-training OUES was related to all-cause (hazard ratio: 0.50, p < 0.001) and CV (hazard ratio: 0.40, p < 0.001) mortality. When significant covariates, including baseline OUES, were entered into the Cox regression analysis, post-training OUES remained related to all-cause and CV mortality (hazard ratio: 0.40, p < 0.01 and 0.26, p < 0.01, respectively). In addition, the change in OUES due to exercise training was positively related to mortality (hazard ratio: 0.49, p < 0.01).
Post-training OUES has stronger prognostic value compared to baseline OUES. The lack of improvement in exercise capacity expressed by OUES after an exercise training program relates to a worse prognosis and can help distinguish patients with favorable and unfavorable prognoses.
峰值摄氧量是冠状动脉疾病（CAD）患者死亡率的独立预测指标。然而，CAD患者并不总是能够达到最大运动强度，因此引入了诸如摄氧效率斜率（OUES）等次极量气体交换变量。用OUES表示的基线运动能力可提供预后信息，且该参数对训练有反应。因此，我们旨在评估训练后OUES对CAD患者的预后价值。
我们纳入了960例CAD患者（年龄60.6±9.5岁；男性853例），这些患者在2000年至2011年间完成了心脏康复计划。在心脏康复前后计算OUES，并获取死亡率信息。通过Cox比例风险回归分析评估训练后OUES与全因死亡率和心血管（CV）死亡率的关系。进行受试者工作特征曲线分析以获得最佳截断值。
在7.37±3.20年的随访期间（范围：0.45 - 13.75年），108例患者死亡，其中47例死于CV原因。训练后OUES与全因死亡率（风险比：0.50，p < 0.001）和CV死亡率（风险比：0.40，p < 0.001）相关。当将包括基线OUES在内的显著协变量纳入Cox回归分析时，训练后OUES仍与全因死亡率和CV死亡率相关（风险比分别为：0.40，p < 0.01和0.26，p < 0.01）。此外，运动训练导致的OUES变化与死亡率呈正相关（风险比：0.49，p < 0.01）。
与基线OUES相比，训练后OUES具有更强的预后价值。运动训练计划后OUES所表示的运动能力缺乏改善与预后较差相关，并且有助于区分预后良好和不良的患者。
