[A new clinical classification of pulmonary hypertension].

The classification of pulmonary hypertension (PHT) has undergone a series of changes since first published in 1973. The initial classification recognized only two categories: primary pulmonary hypertension and secondary pulmonary hypertension, depending on the presence or absence of identified causes or risk factors. In 2008, at the 4th world symposium on PHT at Dana Point (California, USA), an international expert group agreed on the need to revise the previous classifications in order to take into account findings published in the last five years and to clear up certain ambiguities.