Pulmonary venous occlusion and death in pulmonary arterial hypertension: survival analyses using radiographic surrogates

Thirty-seven patients with PAH were enrolled (18 patients, idiopathic PAH; 19 patients, CTD-associated PAH). The patients were 49 ± 18 years and had a World Health Organization functional class of 3.2 ± 0.6. Thickening of the interlobular septa, centrilobular ground-glass attenuation, and mediastinal adenopathy were surrogates for obstruction of the pulmonary veins, and were detected by a 16-row multidetector computed tomography scanner.The follow-up period was 714 ± 552 days. Fifteen deaths occurred. Thickening of the interlobular septa, centrilobular ground-glass attenuation, and mediastinal adenopathy were found in 37.8%, 24.3%, and 16.2% of patients, respectively. Cox proportional hazard analysis revealed an increased risk of death with each radiographic surrogate (mediastinal adenopathy: p < 0.0001, hazard ratio = 13.9; thickening of interlobular septa: p < 0.001, hazard ratio = 12.0; ground-glass attenuation: p = 0.02, hazard ratio = 3.7). The statistical significance of these relationships was independent of the cause of PAH and plasma concentration of brain natriuretic peptide.The results of this study imply that obstruction of the pulmonary veins is associated with an increased risk of death in patients with PAH.Pulmonary arterial hypertension (PAH) carries a significant risk of death [1,2]. Patients with a poor response to pulmonary vasodilating agents often die within several years [1]. Recent studies show that a considerable number of patients with PAH develop fibrous obstruction in the pulmonary veins [3,4]. These findings challenge relationship between clinical entity of PAH and that of pulmonary veno-occlusive disease (PVOD). Case reports suggest that obstruction of pulmonary veins is associated with a poor prognosis [5-8]. However, few researchers have gauged the risk of death due to pulmonary venous obstruction. To assess the effect of pulmonary venous obstruction on the risk of death in patients with PAH, this study performed survival analyses with