Cardiopulmonary Exercise Testing in Patients With Interstitial Lung Disease

Abstract

Interstitial lung disease (ILD) is a heterogeneous group of conditions characterized by fibrosis and/or inflammation of the lung parenchyma. The pathogenesis of ILD consistently results in exertional dyspnea and exercise intolerance. Cardiopulmonary exercise testing (CPET) provides important information concerning the pathophysiology of ILD that can help inform patient management. Despite the purported benefits of CPET, its clinical utility in ILD is not well defined; however, there is a growing body of evidence that provides insight into the potential value of CPET in ILD. Characteristic responses to CPET in patients with ILD include exercise-induced arterial hypoxemia, an exaggerated ventilatory response, a rapid and shallow breathing pattern, critically low inspiratory reserve volume, and elevated sensations of dyspnea and leg discomfort. CPET is used in ILD to determine cause(s) of symptoms such as exertional dyspnea, evaluate functional capacity, inform exercise prescription, and determine the effects of pharmacological and non-pharmacological interventions on exercise capacity and exertional symptoms. However, preliminary evidence suggests that CPET in ILD may also provide valuable prognostic information and can be used to ascertain the degree of exercise-induced pulmonary hypertension. Despite these recent advances, additional research is required to confirm the utility of CPET in patients with ILD. This brief review outlines the clinical utility of CPET in patients with ILD. Typical patterns of response are described and practical issues concerning CPET interpretation in ILD are addressed. Additionally, important unanswered questions relating to the clinical utility of CPET in the assessment, prognostication, and management of patients with ILD are identified.

Cardiopulmonary exercise testing in interstitial lung diseases and the value of ventilatory efficiency

“…CPET also helps to decipher the mechanisms of dyspnoea and exercise limitation of unclear origin, especially when PFTs and transthoracic echocardiogram (TTE) are either normal or both impaired. This is all the more important in ILDs with potential extrapulmonary involvement (sarcoidosis, CTDs) or when deconditioning with peripheral muscle weakness is suspected, which is a frequent situation in chronic lung diseases [5,[46][47][48][49][50]. Moreover, cardiovascular comorbidities are known to be frequent in IPF patients [51][52][53].…”

A role for cardiopulmonary exercise testing in detecting physiological changes underlying health status in Idiopathic pulmonary fibrosis: a feasibility study

“…CPET is considered the gold standard for evaluating exertional dyspnoea and exercise intolerance in patients with cardiorespiratory conditions [ 31 ], yet currently lacks a defined role in the management of ILD [ 31 , 32 ]. A recent systematic review by our group highlighted the insufficient available evidence to support the use of CPET in disease prognostication in ILD, emphasising that heterogeneity in terms of the ILD populations studied and the retrospective nature of the majority of published studies limited the conclusions that could be drawn [ 33 ].…”

Exercise-Based Pulmonary Rehabilitation for Interstitial Lung Diseases: A Review of Components, Prescription, Efficacy, and Safety

“…Cardiopulmonary exercise testing (CPET) provides important information concerning exertional dyspnea and mechanisms of exercise limitation as a comprehensive assessment of the physiological changes in the respiratory, cardiovascular and musculoskeletal systems during exercise, which may be also useful for exercise prescription (17)(18)(19). Maximum and peak oxygen uptake corresponding to a measurement of the capacity for aerobic activity has been linked to survival in ILD patients (18).…”