Long‐term prognostic value of cardiac catheterization and acute vasodilator testing with inhaled iloprost in pediatric idiopathic pulmonary arterial hypertension

To assess the long‐term prognostic value of cardiac catheterization and acute vasodilator testing (AVT) with inhaled iloprost in children with idiopathic pulmonary arterial hypertension (IPAH). Data on 81 consecutive children with IPAH referred to our center who underwent cardiac catheterization and AVT between June 2008 and August 2019 were collected. The correlation between the invasive hemodynamic data and transplant‐free survival was analyzed. Twenty‐four patients died and 1 underwent lung transplantation during a median follow‐up of 3.8 years, with a 5‐year transplant‐free survival rate of 64.9%. Univariate analysis showed that predictors associated with improved survival included a lower pulmonary vascular resistance index (PVRI), PVRI/systemic vascular resistance index (SVRI), mean pulmonary arterial pressure (mPAP)/mean systemic arterial pressure, mean right atrial pressure, and a higher cardiac index (CI), mixed systemic venous oxygen saturations (SvO 2 ), and acute vasodilator response (AVR) according to the Barst criteria (decrease in mPAP and PVRI/SVRI ratio of >20% without a decrease in CI). In multivariate Cox regression analysis, Barst AVR and SvO 2 were independently related to transplant‐free survival. Multiple hemodynamic variables from cardiac catheterization and AVT with inhaled iloprost have important prognostic value for long‐term survival in children with IPAH, of which pulmonary vasoreactivity defined by the Barst criteria and SvO 2 are independent prognostic factors.