Role of Cardiopulmonary Exercise Testing in Stable Chronic Obstructive Pulmonary Disease Patients

Objectives: This study aimed to determine the role of Cardiopulmonary Exercise Testing (CPET) in uncovering the mechanisms of exercise intolerance in mild-to-severe stable chronic obstructive pulmonary disease (COPD) patients and to correlate the spirometry, 6-min walk test (6MWT), and COPD assessment test (CAT) scoring with the exercise capacity in stable COPD patients. This study was conducted at tertiary referral medical college hospital in South India. Methodology: This was a prospective and observational study conducted among all eligible subjects with stable COPD attending outpatient clinic at PSG Institute of Medical Sciences and research over 1 year during 2021–2022. All patients with a history suggestive of asthma, patients with clinically evident active pulmonary tuberculosis, ongoing or recent exacerbations of COPD within 2 weeks prior to enrolment in the study, and coexisting condition that are contraindicated or render forced expiratory maneuver difficult to perform were excluded from the study. A thorough history was taken and systemic examination was performed. Patients with spirometry postbronchodilator forced expiratory volume in 1 s (FEV1)/ Forced vital capacity (FVC)