Pulsatile haemodynamic parameters are predictors of survival in paediatric pulmonary arterial hypertension

Abstract

Background: There is a need for reliable prognostic parameters in pulmonary arterial hypertension (PAH), especially in children. Pulsatile components of the right ventricular afterload, represented by pulmonary arterial compliance (PACi) and pulmonary stroke volume (PSVi), may provide important additional prognostic information to conventional static haemodynamic parameters. The aim of this study was to determine the prognostic value of PACi and PSVi in paediatric PAH.

Methods: Right heart catheterization data of 52 consecutive paediatric idiopathic/hereditary PAH and PAH associated with congenital heart disease patients with full haemodynamic evaluation seen at the Dutch national referral centre for paediatric pulmonary hypertension between 1993 and 2010 were reviewed. A control group was composed of patients with normal pulmonary vascular resistance. PSVi and PACi were calculated and tested for predictive value for transplant-free survival.

Results: PAH patients had significantly lower PSVi and PACi compared to control patients. PSVi and PACi were lower in patients with higher WHO-functional class compared to those with lower functional classes. Higher PSVi, PACi and mSAP and lower mPAP/mSAP and heart rate were associated with improved survival, independent from WHO-functional class and PAH-targeted therapy. In multivariate analyses PSVi, heart rate and mSAP emerged as the strongest haemodynamic predictors of survival. The effect of vasodilator challenge on the haemodynamic variables did not provide additional prognostic information.

Conclusions: The parameters of both the pulsatile and static pulmonary circulations are strong independent predictors for transplant-free survival, and therefore can be of complementary value in assessing disease severity, predicting survival and guiding treatment in paediatric PAH.

Keywords: 6-MWD; 6-minute walk distance; CI; Cardiac catheterization; HR; Haemodynamics; IPAH/HPAH; NO; O2; PAC(i); PAH; PAH-CHD; PP; PSV(i); PVR(i); Paediatrics; Pulmonary hypertension; Qpi; RV; Survival analysis; VO(2); WHO-class; World Health Organization functional class; cardiac index; hazard ratio; idiopathic or hereditary pulmonary arterial hypertension; mPAP; mRAP; mSAP; mean pulmonary arterial pressure; mean right atrial pressure; mean systemic arterial pressure; nitric oxide; oxygen; oxygen consumption; pulmonary arterial compliance (index); pulmonary arterial hypertension; pulmonary arterial hypertension associated with congenital heart disease; pulmonary flow index; pulmonary stroke volume (index); pulmonary vascular resistance (index); pulse pressure; right ventricle.