Pulmonary arterial hypertension associated with congenital heart disease: Comparison of clinical and anatomic-pathophysiologic classification

Between 5% and 10% of patients with congenital heart disease (CHD) develop pulmonary arterial hypertension (PAH-CHD). Patients can be classified using either a clinical or anatomic-pathophysiologic system. No study has previously utilized both systems in a large cohort of patients.

Two hundred forty consecutive PAH-CHD patients diagnosed at a pulmonary hypertension referral center during 1995 to 2014 were identified from our unit database. Baseline characteristics, treatment and survival data were retrieved and survival analyses was performed.

Both systems identified clear differences in baseline characteristics between subgroups. The anatomic-pathophysiologic system identified patients with post-tricuspid defects as having superior survival from point of referral to those with pre-tricuspid or complex defects (p < 0.05). Survival from point of referral was, however, not significantly different when patients were grouped using the clinical classification, although survival in all 4 groups was superior to that of 175 patients with idiopathic pulmonary arterial hypertension. Older age and higher creatinine, lower transfer factor of the lung for DLCO percent predicted and FEV1 percent predicted were independent adverse prognostic factors.

Both PAH-CHD classification systems identified groups of patients distinct in terms of baseline characteristics. In our cohort, however, only the anatomic-pathophysiologic classification identified significantly different survival from point of referral. The presence of adverse prognostic markers may be useful in identifying patients requiring more aggressive pulmonary vascular therapy.