Patients with ACHD with pulmonary hyperten- sion, particularly PAH, have a poorer prognosis than do patients with ACHD with similar histo- ries and anatomic abnormalities who do not have pulmonary hypertension. The fields of ACHD and pulmonary vascular disease care have increasingly disparate but complementary bodies of know- ledge, and both are necessary to achieve op- timal outcomes for patients with PAH. Clinicians cross-trained in both subspecialties or partnering experts from each subspecialty appear necessary to fully counsel patients with ACHD with PAH re- garding: diagnostic evaluation, prognosis, lifestyle choices, suitability for operative or catheter-based repair of existing shunts or vascular obstructions contributing to PAH, nature and effectiveness of additional medical therapies, mechanical circula- tory and pulmonary vascular support, and goals of care. 2. PAH may develop years after shunt closure in patients with ACHD. Predictors for the develop- ment or presence of PAH include: a. Anatomic defects: complete AVSD, sinus ve- nosus defect, large nonrestrictive defect (ASD >2 cm, VSD >1 cm, PDA >0.6 cm), and concomitant ACHD AP classification II or III abnormalities. b. Preintervention Qp:Qs 3 and/or PASP >40 mm Hg. c. Presence of associated syndrome (eg, Down syndrome). Recommendations for Severe PAH (Continued) COR LOE Recommendations Table 33. Pulmonary Hypertension and Eisenmenger Syndrome: Routine Follow-Up and Testing Intervals Frequency of Routine Follow-Up and Testing Physiological Stage C* (mo) Physiological Stage D* (mo) Outpatient ACHD cardiologist 6 12 3 6 Pulse oximetry Each visit Each visit CMR As needed As needed Cardiac catheterization As needed As needed *See Tables 3 and 4 for details on the ACHD AP classification system. Routine TTE may be unnecessary in a year when CMR imaging is performed unless clinical indications warrant otherwise. CMR may be indicated for assessment of right ventricular function and CHD anatomy not clarified with TTE. 