Preoperative Six-Minute-Walk Test in Lung Transplantation: Survival Predictor

Introduction: The 6-minute-walk test (6MWT) is a reproducible and commonly used test that evaluates exercise capacity in patients with severe pulmonary disease. The test results are considered predictors of survival in different pulmonary diseases. Objective: To evaluate the preoperative 6MWT results as predictors of postoperative survival in lung transplant recipients. Methods: A retrospective study of 97 consecutive, adult lung transplant recipients transplanted at our centre from 2009 to 2016. Kaplan-Meier methods and log rank test were used to determine the association between preoperative 6MWT results and post-transplant survival. Results: A total of 79 patients were included, with a mean age of 48 years (SD 13), 46 (58.2%) males, with the most common indication being interstitial lung disease (46.8%). Preoperatively, the median FEV1 was 1020 mL (33.8%), median 6-minute-walk distance (6MWD) was 296m (25th–75th percentiles =180-389 m) and oxygen desaturation was 12% (25th–75th percentiles =7-20%). The median survival was 66,46 months. Walking distance < 180 m correlated with a lower survival (mean 42.2 vs 70.4 months, p=0.03). A pre-transplant higher desaturation (>20%) was also associated with lower survival but without statistical significance (mean 55 vs 70 months, p=0.94). Conclusions: In our group 6MWD, but not oxygen desaturation, was significantly associated with post-transplant survival. This finding may have important implications for the assessment and stratification of individual risk/benefit ratio before proceeding to lung transplantation.