Background diseases in 671 patients with moderate to severe pulmonary hypertension

Background: Data regarding the epidemiology of secondary pulmonary hyperten sion are scanty. Objectives: To describe the spectrum and relative incidenc e of background diseases in patients with significant secondary PHT. Methods: We identified 671 patients with systolic pulmonary artery pressure of 45 mm Hg or more from the database of the echocardiographic laboratory. Their background diseases were recorded and classified into three subgroup s: cardiac, pulmonary and pulmonary vascular disease without pulmonary pare nchymal disease. Age at the first echocardiographic study, gender and systo lic PAP values were recorded. Data between the three subgroups were compare d. Results: The mean age of the patients was 65+/-15 years, mean systolic PAP 61+/-14 mm Hg and female:male ratio 1.21:1. At the time of diagnosis 85% of the patients were older than 50. PHT was secondary to cardiac disease in 5 79 patients (86.3%), to PVD without PPD in 54 patients (8%) and to PPD in o nly 38 patients (5.7%). Mean age and mean systolic PAP did not differ signi ficantly among the three subgroups. There was a significantly higher female : male ratio in patients with PVD without PPD compared with cardiac or pulm onary diseases (1.7:1 vs. 1.2:1 and 1.7 vs. 0.8:1 respectively, P<0.05). Conclusions: The majority of patients with significant PHT are elderly with heart disease. PVD without PPD and chronic PPD are a relatively uncommon c ause of significant PHT Since the diagnosis of PHT is of clinical significa nce and sometimes merits different therapeutic interventions, we recommend screening by Doppler echocardiography for patients with high risk backgroun d diseases.