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

BACKGROUND: Recent studies find that a considerable number of patients with pulmonary arterial hypertension (PAH) develop fibrous obstruction of the pulmonary veins. Such obstruction more commonly accompanies connective tissue disorder (CTD)-associated PAH than idiopathic PAH. However, few researchers have gauged the risk of death involving obstruction of the pulmonary veins. METHODS: 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. RESULTS: 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. CONCLUSIONS: The results of this study imply that obstruction of the pulmonary veins is associated with an increased risk of death in patients with PAH.