Prognosis of pulmonary hypertension in chronic obstructive pulmonary disease

Studies performed since 1968 have shown that in patients with chronic obstructive pulmonary disease (COPD) the prognosis is worse in cases with pulmonary artery hypertension (PAH), especially when the mean pulmonary artery pressure (PPA) is greater than 30 mmHg. Author's data are based on the study of a group of 175 patients with COPD, catheterized between 1968 and 1972. The fate of the patients, at least five years after the initial catheterization, was known in all the cases. The survival rate was calculated according to the "actuarial method". The results suggest that PPA has a good prognostic value, but that FEV1 and PaCO2 are as good predictors of mortality as PPA. Furthermore the influence of age is to be taken into account: prognosis is worse in patients older than 65 years. Longitudinal studies of pulmonary haemodynamics was made in 85 patients who underwent two right heart catheterizations with an interval of greater than 3 years (mean = 5 years) between them. The results indicate that PPA varies very slightly: the average increase for the whole group is 3.1 mmHg, that is less than 1 mmHg per year. There was a good negative correlation between chronological variations of PaO2 and PPA. A long survival time could be observed after the first heart failure episode or after ascertaining pulmonary hypertension.