Abstract
PURPOSE: To evaluate the impact of right ventricular dysfunction on exercise tolerance and potential changes resulting from exercise training in patients with chronic obstructive pulmonary disease (COPD) undergoing pulmonary rehabilitation.
METHODS: Subjects were 44 patients with a history of symptomatic (Global Initiative for Chronic Obstructive Lung Disease classes 2-4) COPD attending a 4-week aerobic exercise training program. Right ventricle dysfunction was evaluated by echocardiography at admission using tricuspid annular plane systolic excursion (TAPSE). Exercise tolerance was evaluated at admission and discharge using the 6-minute walk test (6MWT). Change in distance walked ([DELTA]6MWT) was defined as the difference between 6MWT distance at discharge minus distance at admission. Patients were divided into 2 groups according to the presence of right ventricle dysfunction (TAPSE <=16 mm).
RESULTS: Median age and left ventricular ejection fraction was 70.2 +/- 5.2 years and 54.4 +/- 9.1%, respectively. Of the 44 patients, 14 (31.8%) had TAPSE <=16 mm. Baseline 6MWT distance was less in the group with TAPSE <=16 mm compared with TAPSE >16 mm (110.2 +/- 34 vs 185.7 +/- 41, respectively; P = .02). After the training program, 6MWT distance increased in both groups, but there was less increase in the group with TAPSE <=16 mm compared with TAPSE >16 mm (+24.3% vs +32.8%, respectively; P < .001). Tricuspid annular plane systolic excursion was significantly correlated to distance walked at the baseline 6MWT (r = 0.44; P = .002) and to [DELTA]6MWT (r = .36; P = .006).
CONCLUSIONS: Tricuspid annular plane systolic excursion <=16 mm was an indicator of decreased 6MWT distance at baseline and 6MWT distance change in COPD patients undergoing pulmonary rehabilitation. This relationship seems to be independent of pulmonary function.