Deriving fontan-specific normative exercise data from well-functioning adolescents

Background

Exercise capacity is reduced in patients with a Fontan circulation compared to their healthy peers secondary to altered haemodynamics of the Fontan circulation. Cardiopulmonary exercise testing is routinely used in Fontan patients to assess their cardiopulmonary response to exercise and help guide management decisions, however their results are routinely compared to normative data derived from healthy individuals.

Method

Using data available from the Pediatric Heart Network, we performed a retrospective study to derive Fontan-specific normative values in a subgroup of well-functioning adolescent patients. We utilised results from the Congenital Heart Adolescent and Teenager (CHAT) Questionnaire to classify patients into well-functioning and lower-functioning groups.

Results

We generated Fontan-specific regression equations in adolescent male and females for normative values of peak oxygen consumption (VO₂), maximal workload and VO₂ at anaerobic threshold.

Conclusion

We propose that Fontan-specific normative values are a more useful comparison than healthy normative data due to the known circulatory limitations of the Fontan circulation and will assist in management decision and prognostication.