No drug and no placebo were used in this study. For all the patients who participated at the study PADIS-EP, somme exams must be performed.

No drug and no placebo were used in this study. Some exams must be performed (DLCO - evaluation of the dyspnoea and pulmonary scintigraphy), and in function of the result of the pulmonary scintigraphy, the medical care of the patient will be different : negative pulmonary scintigraphy, stop of the explorations and taken care usual of the patients; positive pulmonary scintigraphy,realisation of a cardiac echography to estimate the presence or not of a not very probable, possible or likely HTP. The indication of the right cardiac catheterization is then put on the combination of the results of the cardiac echography and the evaluation of the dyspnoea.