Idiopathic Pediatric Pulmonary Arterial Hypertension Research Articles

Clinical Characterization of Pediatric Pulmonary Hypertension: Complex Presentation and Diagnosis

To describe the clinical presentation of pediatric pulmonary arterial hypertension (PAH) and the intricacies of how to classify pediatric PAH according to the Venice classification. Children (n = 63) seen at a national referral center for pediatric PAH underwent a diagnostic work-up for diagnosis of pulmonary hypertension (PH) and associated conditions and for assessment of the explanatory role of associated conditions for the PH. Subsequently, PH was classified. In 18 patients (29%), no associated conditions were identified; they were classified as having idiopathic PAH. In 45 patients (71%), > or = 1 associated conditions were detected: congenital heart defects (CHD, n = 40), connective tissue disease (CTD, n = 2), disorders of respiratory system and/or hypoxemia (RSH, n = 17), and chronic thromboembolic disease (CTE, n = 1). Patients were classified according to the condition judged to be primarily explanatory for the PH. In 11 of 45 patients with associated conditions, the PH was not sufficiently explained by these conditions; these patients were classified as having idiopathic-like PAH. In 17 of 40 cases of CHD and 9 of 17 cases of RSH, these conditions were not sufficiently explanatory for the PH. Syndromal abnormalities were frequent (43%). Ultimately, classification revealed idiopathic (-like) PAH (n = 29; 46%), PAH-CHD (n = 23; 37%), PAH-CTD (n = 2; 3%), PH-RSH (n = 8; 12%), and CTE-PH (n = 1; 2%). Pediatric PH frequently presents with associated conditions and syndromal abnormalities. However, detailed evaluation of this complex presentation reveals that associated conditions are not always explanatory for the PH.

Abstract 4380: Transition from IV Epoprostenol to Oral/Inhaled Targeted Pulmonary Arterial Hypertension Therapy in Pediatric Idiopathic Pulmonary Arterial Hypertension

Introduction : Prior to the availability of oral/inhaled (inh) PAH drugs, i.e. 2001–2007, IV epoprostenol (EPO) was the only approved drug for pts un-responsive to calcium channel blockade (CCB). We report our experience transitioning selected pediatric IPAH pts from EPO (initiated prior to 2001) to oral/inh PAH drugs. Methods : We retrospectively reviewed all pediatric IPAH pts treated at Columbia Univ (1991–2008) who transitioned off EPO to oral/inh drugs. Pre-specified criteria for transition included: functional class (FC) I/II, mPAP<35mmHg, normal CO and age > 6 yrs at transition. Hemodynamic and exercise data were obtained at baseline (prior to EPO initiation), at peak EPO dose, and at least 2 mos after EPO discontinuation (d/c) on stable oral/inh drug doses. Data: m ± SD. Results : 13 IPAH pts (6 F) transitioned off EPO between 4/03–11/07 (max dose 100 ± 42ng/kg/min) to oral/inh drugs at 11.6 ± 3.6 yrs of age. Mean duration on EPO: 6.6 ± 3.4yrs (range 1.2–12yrs); f/u post EPO d/c: 10.4 ± 11.6 mos (range 2–42.8 mos). Treatment with EPO improved hemodynamics vs. baseline (p<0.05) with no significant changes in hemodynamics or exercise capacity off EPO. In addition, further improvement was reported in FC off EPO (p<0.002; n=13). Conclusions : In selected IPAH children who began EPO prior to the availability of oral/inh PAH drugs, transition to oral/inh PAH therapy appears safe with efficacy maintained. Whether early initiation of EPO improves long-term outcome vs. deferral of EPO until oral/inh therapy fails remains unknown; further studies with longer-term follow-up are warranted.