Prognostic value of systolic pulmonary artery pressure change at exercise in pulmonary arterial hypertension

The aim of the study was to confirm the prognostic value of haemodynamic parameters during exercise in a prospective series of 53 incident patients with pulmonary arterial hypertension (PAH). Patients were subdivided in 2 groups: group 1 included 22 patients idiopathic, familial or anorexigen-associated PAH and group 2 included 31 patients with other types of PAH. Means and SD values were for the group 1 and 2 : mean pulmonary arterial pressure (PAP) 45 ± 9 mm Hg and 41 ± 11 mm Hg ; cardiac index 2.65 ± 1.13 L/min/m² and 2.73 ± 0.70 L/min/m²; pulmonary vascular resistance 8,7 ± 4,7 UI and 8.1 ± 4.0 UI ; six-minute walk distance 378 ± 142 m and 408 ± 98 m, respectively. During a mean follow-up of 4 years, 7 and 8 patients died in group 1 and 2, respectively. Six-minute walk distance was associated with survival in the two groups. Hazard ratio (HR) per 30 meters were 0.77 (95% confidence interval (CI): 0.65-0.92)(p=0.004) and 0.79 (95% CI: 0.66-0.97)(p=0.023), respectively. No haemodynamic measure was predictive of survival in group 2. Systolic PAP from rest to exercise was the only significant baseline haemodynamic covariate associated with survival in group 1, HR per 10 mm Hg 0.29 (95% CI: 0.13-0.64)(p=0.002). Change from rest to exercise of systolic PAP, an estimate of right ventricle contractile reserve was found as a prognostic factor in at least three independent series of PAH patients. Its use in clinical practice should be evaluated.