Department of Kinesiology & Health Sciences, College of Humanities & Sciences, Virginia Commonwealth University, 1020 W Grace Street, Richmond, VA, 23220, USA.
VCU Pauley Heart Center, Division of Cardiology, Department of Internal Medicine, Virginia Commonwealth University, 1020 E Broad Street, Richmond, VA 23298, USA.
Eur Heart J Qual Care Clin Outcomes. 2022 May 5;8(3):361-367. doi: 10.1093/ehjqcco/qcab032.
Cardiac rehabilitation (CR) improves survival in patients with coronary heart disease (CHD), which is largely mediated by the improvements in cardiorespiratory fitness (CRF) defined as peak oxygen consumption (VO2). Therefore, measuring CRF is essential to predict long-term outcomes in this population. It is unclear, however, whether peak VO2 achieved at the end of CR (END-peak VO2) predicts survival or whether the changes of CRF achieved during CR provide a greater prognostic value. To determine whether END-peak VO2 independently predicts long-term survival in patients with CHD undergoing CR. We also aimed at identifying cut-offs for END-peak VO2 that could be used in clinical practice.
Retrospective analysis of 853 patients with CHD referred to CR who completed a maximal cardiopulmonary exercise test. Survival analysis was performed to examine the risk of all-cause mortality (average follow-up years: 6.65) based on peak VO2. The Contal and O'Quigley's method was used to determine the optimal cut-off of END-peak VO2 based on the log-rank statistic. END-peak VO2 was inversely associated with mortality risk [hazard ratio (HR) = 0.84; 95% confidence interval (CI) = 0.78-0.90], independent of changes in peak VO2 adjusted for the baseline peak VO2. The estimated cut-off of END-peak VO2 at ≥17.6 mL/kg/min best predicted the survival with high predictive accuracy and patients with END-peak VO2 under the cut-off had a greater risk of mortality (HR = 2.93; 95% CI = 1.81-4.74).
In patient with CHD undergoing CR, END-peak VO2 is an independent predictor for long-term survival. Studies utilizing higher intensity CR programmes, with and without pharmacologic strategies, to increase peak VO2 to a greater degree in those achieving a suboptimal END-peak VO2, are urgently needed.
心脏康复（CR）可改善冠心病（CHD）患者的生存率，这在很大程度上是通过心肺适能（CRF）的改善来介导的，CRF 定义为最大摄氧量（VO2）。因此，测量 CRF 对于预测该人群的长期预后至关重要。然而，尚不清楚 CR 结束时的峰值 VO2（END-peak VO2）是否可以预测生存，或者 CR 期间 CRF 的变化是否提供更大的预后价值。为了确定 END-peak VO2 是否可以独立预测接受 CR 的 CHD 患者的长期生存。我们还旨在确定可用于临床实践的 END-peak VO2 的截止值。
对 853 名接受 CR 并完成最大心肺运动测试的 CHD 患者进行回顾性分析。使用生存分析来检查基于 VO2 的全因死亡率的风险（平均随访年限：6.65 年）。使用 Contal 和 O'Quigley 的方法根据对数秩统计量确定 END-peak VO2 的最佳截止值。END-peak VO2 与死亡率风险呈负相关[风险比（HR）=0.84；95%置信区间（CI）=0.78-0.90]，独立于调整基线峰值 VO2 后的峰值 VO2 变化。在≥17.6 mL/kg/min 时，END-peak VO2 的最佳截止值可高度准确地预测生存，且低于截止值的患者死亡率风险更高（HR=2.93；95%CI=1.81-4.74）。
在接受 CR 的 CHD 患者中，END-peak VO2 是长期生存的独立预测因子。迫切需要研究利用更高强度的 CR 方案，包括和不包括药物策略，以增加那些 END-peak VO2 不理想的患者的峰值 VO2 到更大程度。
