Comparison between cardiopulmonary exercise testing parameters and computed tomography findings in patients with thoracic sarcoidosis.

BACKGROUND: Cardiopulmonary exercise testing (CPET) is a safe and clinically useful method to assess functional capacity and to follow disease progression and the response to treatment in several clinical conditions. AIM: We set out to determine the relationship between outcome measures of CPET and high-resolution computed tomography (HRCT) findings in thoracic sarcoidosis.
METHODS: A cross-sectional study was carried out in which 42 nonsmoking outpatients (22 females; median age = 46.5 years) were evaluated. All the patients underwent pulmonary function tests (PFTs) and CPET. By using CPET, the most probable causes of exercise limitation were separated into respiratory mechanics (n = 25) and cardiovascular (n = 17). By using HRCT, the following patterns were recorded: predominant nodules (n = 18), predominant ground-glass opacity (n = 10), and predominant traction bronchiectasis and honeycombing (n = 14).
RESULTS: Although significant differences have been shown for both PFT parameters and CPET results, only the latter were able to distinguish between patients with ground-glass opacity and patients with traction bronchiectasis and honeycombing on HRCT. A statistically significant difference was found for peak VO(2), breathing reserve, and P(A-a)O(2) when patients with predominant traction bronchiectasis and honeycombing were compared to patients with other HRCT patterns (p < 0.0001). There was no statistical difference among the patterns with abnormal CPET and the patterns of abnormalities on HRCT (p > 0.05).
CONCLUSION: The functional capacity assessed by CPET was strongly influenced by HRCT patterns in sarcoidosis. Patients with traction bronchiectasis and honeycombing have lower exercise capacity measured by CPET.