National Astronautics and Space Administration Johnson Space Center, Universities Space Research Association, Houston, Texas, USA.
Am J Cardiol. 2012 Dec 15;110(12):1809-13. doi: 10.1016/j.amjcard.2012.08.015. Epub 2012 Sep 13.
Exercise intolerance is the primary symptom in patients with heart failure and preserved ejection fraction (HFpEF), a major determinant of their decreased quality of life, and an important outcome in clinical trials. Although cardiopulmonary exercise testing (CPET) provides peak and submaximal diagnostic indexes, the reliability of peak treadmill CPET in patients >55 years of age with HFpEF has not been examined. Two CPETs were performed in 52 patients with HFpEF (70 ± 7 years old). The 2 tests were separated by an average of 23 ± 13 days (median 22) and performed under identical conditions, with no intervention or change in status between visits except for initiation of a placebo run-in. A multistep protocol for patient screening, education, and quality control was used. Mean peak oxygen consumption was similar on tests 1 and 2 (14.4 ± 2.4 vs 14.3 ± 2.3 ml/kg/min). Correlation coefficients and intraclass correlations from the testing days were determined (oxygen consumption, r = 0.85, p <0.001, intraclass correlation 0.855; ventilatory anaerobic threshold, r = 0.79, p <0.001, intraclass correlation 0.790; ventilation per carbon dioxide slope, r = 0.87, p <0.001, intraclass correlation 0.864; heart rate, r = 0.94, p <0.001, intraclass correlation 0.938). These results challenge conventional wisdom that serial baseline testing is required in clinical trials with exercise-capacity outcomes. In conclusion, in women and men with HFpEF and severe physical dysfunction, key submaximal and peak ET variables exhibited good reliability and were not significantly altered by a learning effect or placebo administration.
运动不耐受是心力衰竭伴射血分数保留（HFpEF）患者的主要症状，是降低其生活质量的主要决定因素，也是临床试验中的重要结局。虽然心肺运动试验（CPET）提供了峰值和亚最大诊断指标，但在年龄>55 岁的 HFpEF 患者中，峰值跑步机 CPET 的可靠性尚未得到检验。对 52 例 HFpEF 患者进行了 2 次 CPET（70±7 岁）。两次测试平均间隔 23±13 天（中位数 22），在相同条件下进行，两次就诊之间除了开始安慰剂洗脱期外，没有任何干预或状态变化。采用多步骤患者筛选、教育和质量控制方案。第 1 次和第 2 次测试的平均峰值摄氧量相似（14.4±2.4 比 14.3±2.3 ml/kg/min）。从测试日确定相关系数和组内相关系数（摄氧量，r=0.85，p<0.001，组内相关 0.855；通气无氧阈值，r=0.79，p<0.001，组内相关 0.790；通气每二氧化碳斜率，r=0.87，p<0.001，组内相关 0.864；心率，r=0.94，p<0.001，组内相关 0.938）。这些结果对传统观点提出了挑战，即需要在具有运动能力结局的临床试验中进行连续基线测试。总之，在女性和男性 HFpEF 患者中，严重的身体功能障碍患者的关键亚最大和峰值 ET 变量具有良好的可靠性，并且不会因学习效应或安慰剂给药而显著改变。
