Pediatric PAH Prognosis Predicted by WHO Functional Class

In the management of pediatric pulmonary arterial hypertension (PAH), identification of World Health Organization (WHO) Functional Class (FC) deterioration, PAH-related hospitalization, and occurrence/worsening of ≥2 PAH symptoms may be helpful for assessing risk for lung transplantation and/or death. This is according to a study published in the International Journal of Cardiology.

Patients with newly diagnosed (ie, diagnosed 3 months or less before enrollment) idiopathic/familial PAH or PAH-associated congenital heart disease before recruitment (aged 17 years or younger) were enrolled. The following composite clinical worsening (cCW) outcomes recorded at time of enrollment and/or follow-up were analyzed: all-cause death, lung transplantation, PAH-related hospitalization, WHO FC deterioration, atrial septostomy (cCW1, 2, and 3), intravenous/subcutaneous prostanoids initiation, syncope (cCW2, 3), and the incidence/worsening of ≥2 PAH symptoms (cCW3). For WHO FC deterioration, patients needed to have had experienced a numerical increase of ≥1 FC. The researchers also examined the predictive values of the CW definitions and their individual components for death or lung transplantation.

A total of 255 patients were included in the study. The first-event rates per 100 person-years for cCW1, cCW2, and cCW3 were 23.1 (95% CI, 19.3-27.6), 43.6 (95% CI, 37.6-50.6), and 46.3 (95% CI, 40.0-53.7). The most frequently reported first event in each variable was PAH-related hospitalization. Excluding transplantation and death, the cCW definitions comprised end points correlated with high risk for lung transplantation/death (cCW1: hazard ratio [HR], 4.23 [95% CI, 2.27-7.91]; cCW2: HR, 3.25 [95% CI, 1.65-6.39]; cCW3: HR, 2.74 [95% CI, 1.41-5.34]). Factors associated with higher risks included the incidence/worsening of ≥2 PAH symptoms (HR, 2.13; 95% CI, 1.02-4.45), WHO FC deterioration (HR, 3.49; 95% CI, 1.47-8.29), and PAH-related hospitalization (HR, 2.62; 95% CI, 1.32-5.20).

Limitations of the study included its observational nature, the lack of definition for PAH improvement, the relatively small sample size, and the lack of confirmation of therapeutic targets for this patient population.

The researchers wrote that their “findings are of importance for individual monitoring as well as for the individual risk assessment and therapeutic decisions during follow-up in pediatric patients [with PAH].”

Reference

Beghetti M, Brand M, Berger RMF, et al. Meaningful and feasible composite clinical worsening definitions in paediatric pulmonary arterial hypertension: An analysis of the TOPP registry [published online April 25, 2019]. Int J Cardiol. doi:10.1016/j.ijcard.2019.04.062