Pulmonary Hypertension – General Considerations

Pulmonary hypertension (PH) defines an increase in mean pulmonary arterial pressure (PAPm) at a value equal to or greater than 25 mmHg, determined invasively by right cardiac catheterization. The hemodynamic de­fi­ni­tion of PH considers the combination of different he­mo­dy­na­mic parameters: mPAP, pulmonary wedge pressure (PWP), car­diac output (CO), diastolic pressure gradient (DPG) and pul­mo­nary vascular resistance (PVR). The cli­ni­cal cor­res­pon­dence of the haemodynamic definition, con­si­de­ring both the pathological aspect and the therapeutic ap­proach, clas­sifies the clinical conditions that associate PH in five cli­ni­cal groups. Worldwide data on the incidence of pulmonary hypertension are not systematically reported; data on PH prevalence in different aetiologies are not published in detail. PH epi­de­­mio­logy documentation becomes necessary in order to standardize diagnostic and therapeutic management prac­­tices, with particular interest in aligning the dif­feren­ces between different regions of the world, not only geo­gra­phi­cally but also economically. The only data on the survival rate of PH patients in Eastern Europe are published from the Czech Republic registry. The better survival in the throm­bo­em­bo­lic PH subgroup may be positively influenced by the availability of specific pharmacological therapy since 2007. The Portuguese registry reported in 2017 a survival rate at 1, 3 or 5 years of 95%, 77% and 71%, respectively, for new cases with different PH aetiologies, and the absence of statistically significant differences between different ae­tio­logy groups, but with a better prognosis for congenital heart disease related PH cases. For Romania, the National Pul­mo­na­ry Hypertension Register has centralized the data from the six national diagnostic and treatment centres by 2017. The PH pathophysiology is based on pulmonary vascular remodelling by endothelial cell proliferation, smooth muscle cell hypertrophy and perivascular inflammation.