Teste de caminhada de seis minutos como preditor de descompensação clínica em pacientes com cirrose

Abstract

Lower functional capacity is associated with higher morbidity and mortality in several patients who have chronic non-communicable diseases such as lung, cardiovascular, and kidney diseases. The 6-minute walk test (6MWT) is a measure of global functional capacity already recognized and widely used in clinical studies. The shorter distance achieved on the 6MWT is associated with higher mortality in patients with liver cirrhosis and also in those in a liver transplant. The aim of the study was to evaluate whether the impairment of this physical performance can also be associated with the risk of clinical decompensation in patients with cirrhosis, a hypothesis not yet tested in these groups of patients. For this, we raised the question about if the 6MWT has a predictive capacity for clinical decompensation of liver cirrhosis (appearance of ascites, jaundice, upper gastrointestinal bleeding secondary to rupture of esophagogastric variceal or spontaneous bacterial peritonitis) after one year. This is a prospective study involving patients with liver cirrhosis of several etiologies in stable clinical conditions at the moment of their inclusion in the protocol. The patients were followed up for 12 months after the baseline functional assessment by the 6MWT, aiming to identify the occurrence of clinical decompensation of cirrhosis in this period. Differences between groups with and without clinical decompensation were assessed using the independent t-test. The sensitivity and specificity of the 6MWT were determined using the ROC curve (Receiver Operating Characteristic), the area under the curve, and its confidence intervals (95% CI). The cut-off value for the 6MWT that best predicted the appearance of clinical decompensation of cirrhosis was determined using the Youden index and parameters of efficacy. Kaplan-Meier curves were performed to assess cumulative survival considering the 6MWT cut-off point and, to test the difference between these curves was used the adapt the log-rank test. The participants had a mean age of 56.3 ± 10.5 years, 65% were men, 65.4% were classified as Child-Pug Class A, and among the etiologies of cirrhosis, alcohol, virus C, and non-alcoholic steatohepatitis were predominated. The ROC curve determined a DC6M less than 401.8 meters as the cut-off point to predict the appearance of clinical decompensation in patients with cirrhosis with a sensitivity of 64% and specificity of 82%. Survival analysis shows that patients who walked less than 401.8 m during the 6MWT had a decompensation-free survival rate of 30% compared to a 75% rate for those who walked more than 401.8 m (p <0.01). These results show that 6MWD was predictive of clinical decompensation in patients with liver cirrhosis within one year of follow-up. A 401.8-meter cut-off point was associated with an increased risk of clinical decompensation in clinically stable cirrhotic patients at baseline. The 6MWT seems to be useful to be added to the routine prognostic assessment of this population.