Prognoses of primary pulmonary hypertension and chronic majorvessel thromboembolic pulmonary hypertension determined from cumulative survival curves

Abstract

Object Primary pulmonary hypertension (PPH) has a grave prognosis, and chronic majorvessel thromboembolic pulmonary hypertension (TPH) also has a poor prognosis. The purpose of the study is to elucidate the inherent prognoses of two serious diseases. Methods Thirty-two patients with PPH (aged 33±15 years, 1SD) and 48 patients with TPH (aged 50±14 years, 1SD) were used to determine survival curves using Kaplan and Meier's method from the baseline diagnostic catheterization. Definitive diagnosis was made by cardiac catheterization, ultrasonic echocardiography, ventilation-perfusion lung scanning, and pulmonary angiography. Results Mean pulmonary artery pressure (PAm) at the initial examination was 56±16 (mean±1SD) mmHg for patients with PPH and 50±13 mmHg for those with TPH, and did not differ significantly between the two groups. Although these two diseases exhibited equally elevated pulmonary arterial pressures, possibly indicative of a poor prognosis, the survival curves obtained from the prospective study for the two diseases were quite different (p<0.001 by generalized Wilcoxon test, p<0.01 by Log-rank test). Mean survival was calculated to be 3.6 years for PPH and 6.8 years for TPH. Patients with TPH had a longer survival than those with PPH, despite the fact that the age at diagnosis of PPH was younger by 17 years on average than that of TPH. Conclusion The inherent prognoses of the two chronic pulmonary hypertensive diseases prior to the introduction of the recently developed new treatment options are shown and likely indicate that the pulmonary vascular lesions in PPH are consistently progressive, while those of TPH are not as progressive.