Cardiopulmonary exercise testing (CPET) is a noninvasive tool providing information on the interactions between the cardiovascular (CV), pulmonary, and skeletal muscle systems as well as total body metabolic response to exercise. Historically, CPET has been used to evaluate exercise capacity in heart failure and sports cardiology populations, and to help differentiate cardiac versus pulmonary etiologies of exercise limitation. In patients with congenital heart disease (CHD), however, CPET has been underused due to perceived difficulties with data interpretation in the setting of heterogenous cardiac physiology. Nevertheless, CPET is very informative in the population with CHD and should be an important component of longitudinal surveillance to guide treatment, intervention, rehabilitation, and exercise prescription.

In the pediatric population with CHD, CPET interpretation poses unique challenges. Continuous growth and maturation lead to predictable differences in test outcomes, which make comparisons across time difficult. There are, however, pediatric normative values that are age, sex, and size dependent, which facilitate interpretation despite requiring a more subtle approach compared with the fixed percent-predicted cutoffs commonly used in adults.¹ In addition, pediatric patients may have an inability to cooperate with CPET testing on the basis of age. Nevertheless, Kinnear et al. showed that CPET can be safely performed by children ≥10 years of age,² and younger patients can have exercise testing tailored to their developmental age on the basis of established protocols.¹ The ability to perform CPET testing in the pediatric population may provide prognostically informative information, reassure patients and providers, and avoid unnecessary exercise and sport restrictions. Any degree of sport restriction tends to come with associated negative implications for quality of life (QoL), mental health, and long-term health including obesity and CV disease.³

Adults with CHD may similarly benefit from regular CPET testing. These patients are known to have a reduced baseline peak oxygen consumption (V̇O₂) compared with age-related patients without CHD. They can also exhibit variation in exercise capacity on the basis of cardiac lesion, repair type, and chronotropic incompetence (the inability of the heart rate to increase in the setting of exercise).⁴ These limitations to exercise capacity and associated disinclination to physical activity have a demonstrable adverse impact on physical well-being, illness perception, mental health, and overall QoL, and may affect other aspects of life including employment opportunities, sexual health, and reproductive health.⁵ Like in pediatric patients with CHD, CPET in adult patients with CHD can reassure and encourage exercise and sports participation, as well as provide fundamentally important information on clinical status and prognosis.

Current guidelines support regular CPET testing as part of care for adult and pediatric patients with CHD. The most recent sports cardiology recommendations provided recommendations for exercise and sports participation with the emphasis on a shared decision-making process after expert consultation and testing, including CPET.⁶ More specific to CHD, the 2025 American Heart Association (AHA) scientific statement on CPET Interpretation Across the Lifespan in CHD provided evidence-based guidelines for the use of CPET for the pediatric or adult patient with CHD, emphasizing that, even with simple lesions such as atrial and ventricular septal defects, V̇O₂ can be decreased at baseline but improved through exercise.⁷ Finally, the 2025 multisociety Guideline for the Management of Adults With CHD recommends CPET not only as a baseline functional assessment (Class 2a) but also as a metric to be repeated at regular intervals. In adults with CHD, CPET can be used specifically to guide exercise intensity on the basis of clinical status (Class 1), prescribe exercise training and rehabilitation to increase exercise capacity (Class 2a), direct physical activity recommendations (Class 2a), and promote participation in competitive sports as part of a comprehensive evaluation and after discussing benefits versus risks in a shared decision-making process (Class 2a).⁸

CPET is an essential component of CHD care across the lifespan. Figure 1 shows the multiple uses for CPET in: 1) assessing patients with CHD, beginning with baseline evaluation followed by continual re-evaluations based on the need for surgical intervention and changes in clinical status; and 2), in healthy patients with CHD, guiding medical therapy, guiding rehabilitation after surgical intervention, and creating exercise prescriptions to promote safe exercise and sport participation.

Figure 1: Multiple Uses for CPET in the Assessment of Patients With CHD

Longitudinal surveillance in the use of CPET to guide medical management, timing of repair or intervention, rehabilitation after surgical intervention, and creation of exercise prescriptions to promote safe participation in exercise and sports.
CHD = congenital heart disease; CPET = cardiopulmonary exercise testing.

References

1. Guglielmi G, Moscatelli S, Rocchetti G, Agostoni P, Chessa M, Mapelli M. Cardiopulmonary Exercise testing in congenital heart disease: a never-ending story from paediatrics to adult life. Children (Basel). 2025;12(9):1175. Published 2025 Sep 3. doi:10.3390/children12091175
2. Kinnear WJM, Kalinke L, Hull JH. CPET in children. In: Kinnear WJM, Kalinke L, Hull JH, eds. A Practical Guide to the Interpretation of Cardiopulmonary Exercise Tests. 3rd ed. Oxford University Press; 2026.
3. Dean PN, Brothers JA, Burns K, et al. The cardiovascular care of the pediatric athlete. J Am Coll Cardiol. 2025;85(13):1434-1454. doi:10.1016/j.jacc.2025.02.010
4. Wu YH, Lu YS, Tuan SH, et al. Exercise Capacity and pulmonary function in pediatric patients with anomalous pulmonary venous connection post-surgical repair: a retrospective analysis. Kaohsiung J Med Sci. 2026;42(2):e70101. doi:10.1002/kjm2.70101
5. Kacar P, Flander M, Prokselj K. Quality of life in adults with congenital heart disease: insights from a tertiary centre. J Clin Med. 2025;14(20):7451. Published 2025 Oct 21. doi:10.3390/jcm14207451
6. Kim JH, Baggish AL, Levine BD, et al. Clinical considerations for competitive sports participation for athletes with cardiovascular abnormalities: a scientific statement from the American Heart Association and American College of Cardiology. J Am Coll Cardiol. 2025;85(10):1059-1108. doi:10.1016/j.jacc.2024.12.025
7. Cifra B, Cordina RL, Gauthier N, et al. Cardiopulmonary exercise test interpretation across the lifespan in congenital heart disease: a scientific statement from the American Heart Association. J Am Heart Assoc. 2025;14(4):e038200. doi:10.1161/JAHA.124.038200
8. Gurvitz M, Krieger EV, Fuller S, et al. 2025 ACC/AHA/HRS/ISACHD/SCAI guideline for the management of adults with congenital heart disease: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol. 2026;87(7):822-976. doi:10.1016/j.jacc.2025.09.006