Pulmonary arterial hypertension (PAH) has a major impact on mortality and morbidity on congenital heart disease (CHD) patients. Atrial strain in PAH patients has been related to clinical severity and adverse outcomes. The aim of this study was therefore to assess the prognostic role and compare bi-atrial function in patients with CHD-PAH, PAH from other causes (nPAH) and healthy controls.

We included in this prospective cohort study 65 patients with CHD-PAH, 67 patients with nPAH and 65 healthy volunteers. Transthoracic echocardiography, clinical assessment, BNP measurement and 6MWT were performed at baseline. Classic echocardiographic measurements and atrial function studying the 3 different phases strain were measured in both.

Atrial strain parameters are decreased in patients with CHD-PAH as compared to healthy volunteers, especially the right atrial (RA) reservoir (RASR 29,67% vs. 44,15%, P<0,0001) and conduit phase (RASCD −15,85 vs. −28,52, P<0,0001), but also left atrial (LA) reservoir and conduit phases. Active contractile phase seems preserved in both PAH group. Atrial function was comparable between CHD-PAH and nPAH patients. On multivariate analysis, BNP, pericardial effusion, RA ejection fraction, RASR and RASCD were independently associated with death or transplantation. RASR≤30% or RASCD>−8% strain identified patients with a more than 3-fold-increased risk of death or transplant.

Patients with CHD-PAH do not differ in atrial adaptation in comparison with npah. Impaired RASR and RASCD identify high risk PAH patients. RA conduit or reservoir function impairment represents a severity marker of PAH, including in patients with CHD-PAH suggesting the importance of RV diastolic dysfunction. This might be an early marker of poor prognosis (Figure 1).