A pulmonary hypertension (PH) registry (Spanish Registry of Pulmonary Arterial Hypertension) was undertaken to analyse prevalence, incidence and survival of pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) in Spain, and to assess the applicability of recent survival prediction equations.Voluntary reporting of previously diagnosed and incident PAH or CTEPH cases (July 2007-June 2008) was performed. Demographic, functional and haemodynamic variables were evaluated.866 patients with PAH and 162 with CTEPH were included. PAH associated with toxic oil syndrome and pulmonary veno-occlusive disease were reported for the first time in a PAH registry. Estimated prevalences were as follows: PAH, 16 and CTEPH, 3.2 cases per million adult inhabitants (MAI). Estimated incidences were as follows: PAH, 3.7 and CTEPH, 0.9 cases per MAI per yr. 1-, 3-and 5-yr survival was 87%, 75% and 65%, respectively, with no differences between PAH and CTEPH. Male sex, right atrial pressure and cardiac index were independent predictors of death. Matching between observed survival and that predicted by different equations was closer when the characteristics of the cohorts were similar.Epidemiology and survival of PAH patients in the Spanish registry are similar to recent registries. Characteristics of the population from which survival prediction equations are derived influence their applicability to a different cohort. CTEPH is much less prevalent than PAH, although has a similar survival rate.

Pulmonary arterial hypertension (PAH) is a rare devastating disease characterized by a high genetic heterogeneity with several related genes recently described, including BMPR2,TBX4 and KCNK3. The association between KCNK3 and PAH has been recently identified, but the prognosis and phenotype associated with these mutations have been poorly described. We studied a series of 136 idiopathic and hereditary PAH Spanish patients for BMPR2, TBX4 and KCNK3 mutations. We report the results of KCNK3 in which we were able to describe two new mutations (p.Gly106Arg and p.Leu214Arg) in three patients. The first one was found in a patient belonging to a consanguineous Romani family, who carried a homozygous mutation in KCNK3 and developed a severe and early form of the disease. To the best of our knowledge, this is the first time that a homozygous mutation in KCNK3 is reported in a PAH patient. The second one was found in a patient who presented at the young adult age a severe form of the disease. The present report supports the contribution of KCNK3 mutations to the genetic etiology of PAH and strongly suggests that mutations in KCNK3 follow incomplete dominance with worsening of the clinical features in homozygous patients.

No abstract