Cardiopulmonary Exercise Testing Provides Additional Prognostic Information in Cystic Fibrosis

Abstract

RATIONALE: The prognostic value of cardiopulmonary exercise testing (CPET) for survival in cystic fibrosis (CF) in the context of current clinical management, when controlling for other known prognostic factors is unclear. OBJECTIVES: To determine the prognostic value of CPET-derived measures beyond peak oxygen uptake (VO2peak) following rigorous adjustment for other predictors. MEASUREMENTS AND MAIN RESULTS: Data from 10 CF-centers in Australia, Europe and North America were collected retrospectively. 510 patients completed a cycle CPET between January 2000 and December 2007, of which 433 fulfilled the criteria for a maximal effort. Time to death/lung transplantation (LTx) was analyzed using Cox proportional hazards regression. In addition, phenotyping using hirarchical Ward's clustering was performed to characterize high risk subgroups. Cox regression showed-even after adjustment for sex, forced expiratory volume in 1s (%predicted), body mass index (z-score), age at CPET, Pseudomonas aeruginosa status, and CF-related diabetes as covariates in the model-that VO2peak in %predicted, hazard ratio (HR) 0.964 [95%-CI: 0.944-0.986], peak work rate (%predicted, HR 0.969 [0.951-0.988], ventilatory equivalent for oxygen (VE/VO2peak) HR 1.085 [1.041-1.132], and carbon dioxide (VE/VCO2peak), HR 1.060 [1.007-1.115], all P<0.05) were significant predictors of death or LTx at 10 years follow-up. Phenotyping revealed that CPET-derived measures were important for clustering. We identified a high risk cluster characterized by poor lung function, nutritional status and exercise capacity. CONCLUSIONS: In conclusion, CPET provides additional prognostic information to established predictors of death/LTx in CF. High risk patients may especially benefit from regular monitoring of exercise capacity and exercise counselling.

Exercise testing and exercise training within cystic fibrosis centres across Australia and New Zealand: what is considered important and what is current practice?

“…International groups support the completion of annual laboratory‐based exercise tests in people with CF . The results of this survey highlight the infrequent use of this type of exercise test in Australian and New Zealand CF centres.…”

“…Regarding testing, international recommendations support the completion of annual laboratory‐based exercise testing (i.e. a cardiopulmonary exercise test (CPET)) to identify exercise intolerance, guide exercise prescription and for prognostication . Work done 15 years ago in the United Kingdom and Germany reported that annual CPET data were collected on less than 50% of CF people living with the uptake compromised by cost, the need for specialised equipment and technical expertise to conduct these tests with .…”

Cystic fibrosis year in review 2018, part 1

“…Exercise performance has long been known to be an independent predictor of mortality. In a retrospective multinational study of 433 children and adults with CF who performed CPET, VO2peak, VE/VO2, and VE/VCO2 were independently associated with death or lung transplant over a 10‐year period, even after adjustment for other risk factors including age at CPET, sex, BMI, CF‐related diabetes, and infection with PA . A cluster of patients with low pulmonary function, poor nutritional status, and abnormal CPET parameters were at particularly high risk of mortality.…”

High-Intensity Interval Training Is Effective at Increasing Exercise Endurance Capacity and Is Well Tolerated by Adults with Cystic Fibrosis

“…The cause of such reduction is multifactorial and includes impairments in lung function as well as peripheral and respiratory muscle deconditioning, the latter of which contributes to breathlessness and muscle fatigue during exercise [ 2 , 3 ]. In this population, as greater exercise capacity has been associated with better health-related quality of life (HRQoL) [ 4 , 5 ] and survival [ 6 , 7 , 8 ], maintaining or improving exercise capacity is an important treatment goal.…”