Costa Henrique Silveira, Lima Márcia Maria Oliveira, Lage Susan Martins, da Costa Fábio Silva Martins, Figueiredo Pedro Henrique Scheidt, da Costa Rocha Manoel Otávio
Postgraduate Course of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Medical School and Hospital das Clínicas of the Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil.
School of Biological and Health Sciences, School of Physiotherapy, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Brazil.
J Exerc Rehabil. 2018 Oct 31;14(5):844-850. doi: 10.12965/jer.1836326.163. eCollection 2018 Oct.
Chagas heart disease (CHD) leads to a progressive functional impairment. Field tests, as the 6-min walk test (6MWT) and the incremental shuttle walk test (ISWT), may be inexpensive approaches in the evaluation of functional capacity of these patients. The present study was addressed to compare the 6MWT and the ISWT measures, and to determine the accuracy of these tests in the identification of functional impairment in patients with CHD. Thirty-five patients with CHD (47.1±8.2 years, NYHA I-III) were evaluated by echocardiography, cardiopulmonary exercise test (CPET), 6MWT, and ISWT. Correlations between the CPET (peak oxygen uptake [peak VO2] and the ratio between ventilation and the carbon dioxide production [VE/VCO2 slope]) and the field tests (walking distances) were also performed. The receiver operating characteristic (ROC) curve was selected to identify the best distances related to identify those patients with functional impairment. There was no difference between distances walked during the 6MWT and ISWT (=0.694). The Bland-Altman analysis showed good agreement between the field tests. Both 6MWT and ISWT correlated with peak VO2 (=0.577, <0.001 and =0.587, <0.001, respectively) and ISWT correlated with VE/VCO2 slope (=-0.339, =0.003). The cutoff distances of 6MWT and ISWT to identify patients with peak VO2 less than 20 mL/kg/min were 520 m and 400 m, respectively, with no difference between the areas under ROC curves (=0.276). Both the 6MWT and the ISWT demonstrated accuracy in identify functional impairment in patients with CHD, being useful tools for the risk stratification of these patients.
恰加斯心脏病（CHD）会导致进行性功能损害。像6分钟步行试验（6MWT）和递增往返步行试验（ISWT）这样的现场试验，可能是评估这些患者功能能力的低成本方法。本研究旨在比较6MWT和ISWT测量结果，并确定这些测试在识别CHD患者功能损害方面的准确性。对35例CHD患者（47.1±8.2岁，纽约心脏协会心功能分级I - III级）进行了超声心动图、心肺运动试验（CPET）、6MWT和ISWT评估。还进行了CPET（峰值摄氧量[peak VO2]以及通气与二氧化碳产生量之比[VE/VCO2斜率]）与现场试验（步行距离）之间的相关性分析。选择受试者工作特征（ROC）曲线来确定与识别功能损害患者相关的最佳距离。6MWT和ISWT期间的步行距离之间没有差异（P = 0.694）。Bland - Altman分析显示现场试验之间具有良好的一致性。6MWT和ISWT均与peak VO2相关（分别为r = 0.577，P < 0.001和r = 0.587，P < 0.001），且ISWT与VE/VCO2斜率相关（r = -0.339，P = 0.003）。识别peak VO2小于20 mL/kg/min患者的6MWT和ISWT的截断距离分别为520 m和400 m，ROC曲线下面积之间没有差异（P = 0.276）。6MWT和ISWT在识别CHD患者的功能损害方面均显示出准确性，是这些患者风险分层的有用工具。
