Alves Rafael, Lima Marcia M, Fonseca Cheyenne, Dos Reis Rodrigo, Figueiredo Pedro H, Costa Henrique, Kreuser Lucas, Nunes Maria C, Ribeiro Antonio L
Department of Internal Medicine Medical School and Hospital das Clinicas of the Federal University of Minas Gerais (UFMG) Belo Horizonte, Brazil -
Eur J Phys Rehabil Med. 2016 Feb;52(1):20-7. Epub 2015 Nov 4.
Chagas heart disease (CHD) patients may have a reduced functional capacity (FC). Field tests, as the Incremental Shuttle Walk Test (ISWT), can estimate peak oxygen uptake (VO2 peak). However, the relationship between the ISWT and the Cardiopulmonary Exercise Testing (CPET), the gold standard in the assessment of FC, is not well established in CHD patients.
This study aimed to evaluate the FC of CHD patients by ISWT with direct measurement of VO2 peak and to compare these findings with data obtained from CPET. A secondary goal was to derive a regression equation to calculate the VO2 peak by ISWT.
Cross-sectional and correlative study.
Research laboratory setting.
Thirty-two CHD patients (58.8±9.0 years, 81.3% women) participated in this study.
Eligible patients underwent clinical evaluation, echocardiography, CPET by ramp protocol and ISWT according to current guidelines.
The distance walked in ISWT showed a positive correlation with VO2 peak from CPET and ISWT (r=0.456, P=0.009 and r=0.869, P<0.001, respectively). In the agreement analysis, the values of the differences between VO2 peak from CPET and ISWT showed absence of bias (mean bias ±95% CI and mean -1.29±5.09 mL.kg.min). Based in real values of VO2 obtained from ISWT, one equation including sex, functional class and distance walked was provided to predict the VO2 values in this test.
This study showed the good correlation between distance walked in ISWT and VO2 peak directly measured in both tests, and additionally, provided an equation to calculate a predictive VO2 peak by ISWT, suggesting a good alternative to evaluate the FC of CHD patients, especially in locations where sophisticated testing is not available.
The results confirm the possibility of using the ISWT for the evaluation of the FC in patients with CHD, especially in locations where sophisticated testing is not available.
恰加斯心脏病（CHD）患者的功能能力（FC）可能会降低。像递增往返步行试验（ISWT）这样的现场测试可以估算峰值摄氧量（VO2峰值）。然而，在CHD患者中，ISWT与心肺运动试验（CPET，评估FC的金标准）之间的关系尚未明确确立。
本研究旨在通过ISWT直接测量VO2峰值来评估CHD患者的FC，并将这些结果与从CPET获得的数据进行比较。第二个目标是推导一个回归方程，通过ISWT计算VO2峰值。
横断面相关性研究。
研究实验室环境。
32名CHD患者（年龄58.8±9.0岁，81.3%为女性）参与了本研究。
符合条件的患者接受临床评估、超声心动图检查、按斜坡方案进行的CPET以及根据现行指南进行的ISWT。
ISWT中的步行距离与CPET和ISWT的VO2峰值呈正相关（分别为r = 0.456，P = 0.009和r = 0.869，P < 0.001）。在一致性分析中，CPET和ISWT的VO2峰值之间的差异值显示无偏差（平均偏差±95%CI，平均为 -1.29±5.09 mL·kg·min）。基于从ISWT获得的VO2实际值，提供了一个包含性别、功能分级和步行距离的方程，以预测该测试中的VO2值。
本研究表明ISWT中的步行距离与两种测试中直接测量的VO2峰值之间具有良好的相关性，此外，还提供了一个通过ISWT计算预测性VO2峰值的方程，这表明ISWT是评估CHD患者FC的一个很好的替代方法，特别是在无法进行复杂测试的地方。
结果证实了使用ISWT评估CHD患者FC的可能性，特别是在无法进行复杂测试的地方。
