Assessing pulmonary hypertensive vascular disease in childhood. Data from the Spanish registry

Rationale: There is a lack of knowledge regarding the epidemiology, clinical characterization, and survival in pediatric pulmonary hypertension.

Objectives: To describe the epidemiology, outcomes, and risk factors for mortality in pediatric pulmonary hypertension in Spain.

Methods: We analyzed data from the Spanish Registry for Pediatric Pulmonary Hypertension. From January 2009 to June 2012, a total of 225 patients diagnosed with pulmonary hypertension in 1998 or after were collected from 21 referral and nonreferral centers. We included all Nice etiologies, estimated incidence and prevalence of pulmonary hypertension in the Spanish pediatric population, and analyzed risk factors for mortality (Nice etiologic group, clinical and hemodynamic variables). Patients were classified as follows: group I, pulmonary arterial hypertension (n = 142; 61%); group II, left heart disease (n = 31; 14%); group III, respiratory disease (n = 41; 18%); group IV, thromboembolic pulmonary hypertension (n = 2; 1%); or group V, mostly inherited metabolic diseases (n = 10; 4.5%). Of the patients studied, 31% had multifactorial pulmonary hypertension.

Measurements and main results: Mean age at diagnosis was 4.3 ± 4.9 years (50% < 2 yr). Survival rates at 1 and 3 years were 80 and 74% for the whole cohort, and 89 and 85% for patients with pulmonary arterial hypertension. Independent risk factors for mortality included an etiologic group other than pulmonary arterial hypertension (P < 0.001), age at diagnosis younger than 2 years old (P < 0.001), advanced functional class at diagnosis (P < 0.001), and high right atrial pressure at diagnosis (P = 0.002).

Conclusions: In moderate to severe pediatric pulmonary hypertension, the prognosis is better in pulmonary arterial hypertension than in other Nice categories. In pediatric pulmonary hypertension age at diagnosis younger than 2 years is a risk factor for mortality, in addition to the previously established risk factors.