Cardiovascular complications in patients with interstitial lung disease and their correlation with 6-minute walk test and spirometry

Abstract

Introduction: Pulmonary hypertension and other cardiac complications occur frequently due to chronic hypoxia induced by interstitial lung diseases (ILD) or due to connective tissue disorder itself. Two-dimensional (2D) echocardiography is ideal for identifying abnormalities at a given time. In this study, we tried to detect cardiovascular complications in patients with ILD using 2D echocardiography and correlate them with a 6-minute walk test (6 MWT) and spirometry. Materials and Methods: This study was carried out for 18 months including 100 consecutive cases of ILD. The diagnosis was made using the latest criteria as per the disease and high-resolution computed tomography (HRCT) thorax. All patients were evaluated with 2D echocardiography, 6 MWT, and spirometry along with routine investigations. Their results were analyzed using STATA 15.1 software. Result: Cardiovascular involvement was detected in 68% of cases. Pulmonary hypertension predominated with a prevalence of 50%. In spirometry, mean Forced expiratory volume in first second (FEV 1 )and Forced vital capacity (FVC) were found to be 54.96 (L) and 53.49 (L), respectively, with a predominant restrictive pattern (89%). There was a significant correlation between baseline saturation of oxygen (SpO 2 ) and pulmonary arterial systolic pressure (PASP) with a P value of <0.05. Baseline SpO 2 and distance covered in 6 MWT had a significant correlation ( P = 0.014). Conclusion: A baseline or nighttime hypoxia is responsible for developing PAH. Pulmonary arterial hypertension should be suspected in patients unable to perform 6 MWT or having low baseline SpO 2 . A routine follow-up with a 6 MWT and baseline SpO 2 should be performed in each visit to identify early deterioration of the disease.

Assessment of the feasibility of 1-min sit-to-stand test in evaluating functional exercise capacity in interstitial lung disease patients

“…6MWT is the most widely used investigation for assessing exercise tolerance in ILD patients. In the present study, distance walked by the patients during 6MWT was 332.4±67.0 m. This was similar to earlier studies by Devani et al (2019) and Gupta et al (2021) but other studies yielded higher values of 6MWD ( Fedi et al, 2021 ; Tremblay Labrecque et al, 2020 ). This difference could be due to variations in the body stature as well as due to difference in the extent of ILD in the mentioned studies.…”