Roul G, Germain P, Bareiss P
Cardiology Department, Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, France.
Am Heart J. 1998 Sep;136(3):449-57. doi: 10.1016/s0002-8703(98)70219-4.
We prospectively evaluated the potential of the 6-minute walk test compared with peak VO2 in predicting outcome of patients with New York Heart Association (NYHA) class II or III heart failure.
Patients with a history of heart failure caused by systolic dysfunction were included. The combined final outcome (death or hospitalization for heart failure) was used as the judgment criterion. One hundred twenty-one patients (age 59+/-11 years; left ventricular ejection fraction 29.6%+/-13%) were included and followed for 1.53+/-0.98 years. Patients were separated into two groups according to outcome: group 1 (G1, 74 patients), without events, and group 2 (G2, 47 patients), who reached the combined end point. Peak VO2 was clearly different between G1 and G2 (18.5+/-4 vs. 13.9+/-4 ml/kg/min, p=0.0001) but not the distance walked (448+/-92 vs 410+/-126 m; p=0.084, not significant). Survival analysis showed that unlike peak VO2, the distance covered was barely distinguishable between the groups (p < 0.08). However, receiver operating characteristic curves revealed that the best performances for the 6-minute walk test were obtained for subjects walking < or =300 m. These patients had a worse prognosis than those walking farther (p=0.013). In this subset of patients, there was a significant correlation between distance covered and peak VO2 (r=0.65, p=0.011). Thus it appears that the more severely affected patients have a daily activity level relatively close to their maximal exercise capacity. Nevertheless, the 300 m threshold suggested by this study needs to be validated in an independent population.
A distance walked in 6 minutes < or =300 m can predict outcome. Moreover, in these cases there is a significant correlation between the 6-minute walk test and peak VO2 demonstrating the potential of this simple procedure as a first-line screening test for this subset of patients.
我们前瞻性地评估了6分钟步行试验相较于峰值摄氧量在预测纽约心脏协会（NYHA）II级或III级心力衰竭患者预后方面的潜力。
纳入有收缩功能障碍所致心力衰竭病史的患者。将联合最终结局（死亡或因心力衰竭住院）用作判断标准。纳入121例患者（年龄59±11岁；左心室射血分数29.6%±13%），随访1.53±0.98年。根据结局将患者分为两组：第1组（G1，74例患者），无事件发生；第2组（G2，47例患者），达到联合终点。G1和G2之间的峰值摄氧量有明显差异（18.5±4 vs. 13.9±4 ml/kg/min，p = 0.0001），但步行距离无差异（448±92 vs 410±126 m；p = 0.084，无统计学意义）。生存分析表明，与峰值摄氧量不同，两组之间的步行距离几乎无差异（p < 0.08）。然而，受试者工作特征曲线显示，6分钟步行试验对于步行≤300 m的受试者表现最佳。这些患者的预后比步行更远的患者更差（p = 0.013）。在这组患者中，步行距离与峰值摄氧量之间存在显著相关性（r = 0.65，p = 0.011）。因此，似乎病情越严重的患者日常活动水平相对接近其最大运动能力。尽管如此，本研究提出的300 m阈值需要在独立人群中进行验证。
6分钟步行距离≤300 m可预测预后。此外，在这些病例中，6分钟步行试验与峰值摄氧量之间存在显著相关性，表明这一简单程序作为该组患者一线筛查试验的潜力。
