Assessment of survival in patients with primary pulmonary hypertension: Importance of cardiopulmonary exercise testing

Primary pulmonary hypertension (PPH) is a life-threatening disease. Prognostic assessment is an important factor in determining medical treatment and lung transplantation. Whether cardiopulmonary exercise testing data predict survival has not been reported previously. We studied 86 patients with PPH (58 female, age 46+/-2 years, median NYHA class III) between 1996 and 2001 who were followed up in a tertiary referral center. Right heart catheterization was performed and serum uric acid levels were measured in all patients. Seventy patients were able to undergo exercise testing. At the start of the study, the average pulmonary artery pressure was 60+/-2 mm Hg, average pulmonary vascular resistance was 1664+/-81 dyne x s x cm(-5), average serum uric acid level was 7.5+/-0.35 mg/dL, and average peak oxygen uptake during exercise (peak VO(2) was 11.2+/-0.5 mL x kg(-1) x min(-1). During follow-up (mean: 567+/-48 days), 28 patients died and 16 underwent lung transplantation (1-year cumulative event-free survival: 68%; 95% CI 58 to 78). The strongest predictors of impaired survival were low peak VO(2) (P