COR LOE Recommendations IIa B-NR In patients with ACHD, cardiopulmonary exercise testing (CPET) can be useful for baseline functional assessment and serial IIa C-LD In symptomatic patients with ACHD, a 6-minute walk test can be useful to objectively assess symptom severity, functional capacity, and response to therapy.S3.4.7-3,S3.4.7-4 Recommendation-Specific Supportive Text 1. Patients with ACHD often overestimate their physical capabilities and underreport limitations. In contrast to patients with acquired heart di- sease, patients with ACHD may never have ex- perienced normal function. Decline in physical capacity may occur imperceptibly over many Consequently, tools more precise than patient history are necessary for evaluation and serial follow-up of functional capacity. CPET provides objective, reproducible, and repeatable assessment of the cardiovascular, respiratory, and muscular systems and has been shown to have prognostic value in patients with a wide variety of 2. In severely impaired patients with ACHD, or those who cannot complete CPET for other reasons, the 6-minute walk test provides a more limited set of data, which nevertheless has prognostic value be- yond history alone.S3.4.7-3,S3.4.7-4 CLINICAL STATEMENTS AND GUIDELINES 3.5. Transition Education Recommendation for Transition Education Referenced studies that support the recommendation are summarized in Online Data Supplement 12. COR LOE Recommendation I B-NR Clinicians caring for patients with CHD should deliver developmentally appropriate transition education to adolescent and young patients with CHD, and to their Recommendation-Specific Supportive Text 1. Preparing a patient for independent cardiac care is an ongoing process that should start in early ado- lescence if not soonerS3.5-3 and may extend beyond 18 years of age in many patients. 