Prognostic value of pulmonary artery pressure in chronic obstructive pulmonary disease

Abstract

In 175 patients with chronic obstructive lung disease (157 chronic bronchitic and 18 emphysematous patients) exhibiting moderate to severe airway obstruction (mean FEV1/vital capacity = 40.2 +/- 11.1%), cumulative survival rates calculated by the actuarial method were compared in subgroups according to the initial level of mean pulmonary artery pressure, pulmonary volumes, and arterial blood gases. Patients were catheterised between 1968 and 1972 and were followed for at least five years. The results emphasise the high prognostic value of PAP since survival rates after four and seven years were significantly lower in the subgroup with PAP greater than 20 mmHg (2.7 kPa). Certain other parameters ("driving" pressure across the pulmonary circulation, FEV1 and Paco2) appear to be equally good at predicting survival as PAP in these obstructed patients. The effect of age should be taken into account in prognostic studies such as ours since survival rates were significantly lower in patients over 60 years of age. In 64 patients who underwent a second right heart catheterisation at least three years after the first (average delay: 5.5 +/- 2 years), the prognostic value of changes in PAP, arterial blood gases, and pulmonary volumes was studied but with the exception of Pao2 was unremarkable. Further studies are needed in this field.