ERS technical standard on reference values for cardiopulmonary exercise testing: summary report and a call for action

Area of Science:

• Exercise Physiology
• Clinical Measurement
• Biostatistics

Background:

• Cardiopulmonary exercise testing (CPET) is crucial for assessing physiological responses to exercise and identifying limitations.
• Existing reference equations for CPET outcomes are population-specific and do not cover the full human age range.
• Establishing global, all-age reference ranges for CPET is a significant clinical need.

Purpose of the Study:

• To derive Global Lung Function Initiative (GLI) reference equations for peak oxygen uptake (VO2peak) and peak work rate (Wpeak) in healthy individuals across the human age span.
• To investigate the feasibility of creating universal reference ranges for CPET outcomes.

Main Methods:

• Retrospective collection of CPET data from 5956 healthy individuals aged 6-83 years across 17 international sites.
• Utilized Generalized Additive Models for Location, Scale and Shape (GAMLSS) incorporating age, sex, height, and weight.
• Examined the impact of geographic region, equipment, testing protocols, and data averaging methods on peak exercise variables.

Main Results:

• Substantial between-subject variability observed in both VO2peak and Wpeak, with wide confidence intervals across age groups.
• Heterogeneity in VO2peak was linked to geographic region, metabolic cart type, and averaging methods.
• While controlling for these factors improved model fit, they were insufficient for reliable reference range prediction.

Conclusions:

• Significant heterogeneity in CPET methodology and outcomes across testing sites prevented the development of reliable VO2peak and Wpeak reference ranges.
• A framework for prospective data collection with standardized protocols and centralized analysis is proposed.
• This framework aims to reduce variability and establish robust, clinically meaningful reference ranges for CPET outcomes.