Group D of pulmonary arterial hypertension and its relationship to congenital heart disease: Is there a non-invasive way to predict the unpredictable?

Pulmonary arterial hypertension related to congenital heart disease (PAH-CHD), can pose a few challenging therapeutic challenges. PAH related to CHD can be classified into 4 clinical groups: Group A, which includes patients with Eisenmenger syndrome; Group B, which includes patients with severe PAH due to significant shunt lesions with no reversal of the shunt and no cyanosis; Group C, which includes patients with PAH due to small defects whose clinical picture is comparable to that of IPAH (idiopathic PAH) patients; and Group D, which includes patients with persistent PAH following CHD repair. This review aims to shed light on the possible laboratory markers that can predict whether pulmonary arterial hypertension secondary to a congenital heart defect will improve after repair of the defect or will continue to progress because the patient's PAH is mediated by idiopathic changes and not the shunt lesion itself. This differentiation is crucial for predicting PH prognosis after cardiac repair. See Figure 1 for graphical abstract. 10.7717/gcsp.202505/fig-1Figure 1.Graphical abstract showing laboratory predictors of irreversible pulmonary arterial hypertension.