峰值氧耗量和无氧代谢阈值对慢性心力衰竭患者预后的预测价值

摘要

ObjectiveTo measure the peak oxygen consumption (peak VO2) and oxygen uptake at anaerobic threshold (VO2AT) by cardiopulmonary exercise testing (CPET) in patients with chronic heart failure (CHF) and evaluate the prognostic values of the 2 indices. Methods Totally 129 patients suffering from CHF with left ventricular ejection fraction (LVEF)<0.49 by echocardiography admitted in our department were recruited in this study. Coronary angiography indicated that there were 74 cases of ischemic cardiomyopathy and 55 cases of dilated cardiomyopathy. All subjects underwent CPET on the bicycle ergometer and were followed up for cardiac-related mortality in duration of median 33.7 months.Results (1) During the follow-up, 19 cardiac deaths were identified. There was no differences in the age, sex, body mass index (BMI) and peak respiratory exchange ratio (peak RER) between those dead patients and the survivors (P>0.05). But LVEF (0.33±0.09vs 0.38±0.09), peak VO2 [11.8±4.3vs 14.4±3.7ml/(kg·min)] and VO2AT [9.3±3.2vs 10.7±2.1ml/(kg·min)] were obviousty lower, while left ventricular mass index (LVMI, 158.3±53.9vs 133.2±40.1) was significantly higher in the dead ones than in the survivors (allP<0.05). (2) By receiver operating characteristic (ROC) curve analysis, the area under curve (AUC) of peak VO2 was 0.640 in predicting cardiac-related mortality in CHF patients (P<0.05), the sensitivity was 0.590, the specificity was 0.667, and the optimal threshold value of peak VO2 was≤13.4ml/(kg·min). The AUC of VO2AT was 0.600 (P<0.05), the sensitivity was 0.886, the specificity was 0.360, and the optimal threshold value of VO2AT was≤8.2ml/(kg·min).Conclusion Peak VO2 and VO2AT have certain predictive values for cardiac-related mortality in CHF patients, and the former is superior to the latter.%目的：通过心肺运动试验（CPET）检测慢性心力衰竭（CHF）患者峰值氧耗量（peak VO2）和无氧代谢阈值氧耗量（VO2AT），并随访其预后价值。方法选择入住同济大学附属同济医院心内科并经心脏超声确定左室射血分数（LVEF）＜0.49的CHF患者129例（经冠状动脉造影确诊的缺血性心肌病74例，扩张型心肌病55例）。对入选患者实施CPET，并对患者随访心血管死亡原因（时间中位数为33.7个月）。结果（1）19例CHF患者因心血管原因死亡，死亡患者和非死亡患者在年龄、性别、BMI、峰值吸呼比（peak RER）差异无统计学意义的情况下（P＞0.05），死亡患者较非死亡患者左室射血分数（LVEF）减低[（0.33±0.09） vs （0.38±0.09），P＜0.05]；左心室质量指数（LVMI）增高[（158.3±53.9）vs（133.2±40.1），P＜0.05]；peak VO2减低[（11.8±4.3）vs（14.4±3.7）ml/（kg·min），P＜0.05]；VO2AT减低[（9.3±3.2）vs（10.7±2.1）ml/（kg·min），P＜0.05]。（2）peak VO2的ROC曲线下面积（AUC）为0.640（P＜0.05），灵敏度为0.590，特异度为0.667，最佳阈值为peak VO2≤13.4ml/（kg·min）；VO2AT的AUC为0.600（P＞0.05），灵敏度为0.886，特异度为0.360，最佳阈值为VO2AT≤8.2ml/（kg·min）。结论 peak VO2及VO2AT对CHF患者心血管原因死亡具有一定的预测价值，peak VO2的预测价值优于VO2AT。