D109-05 Small Vessel Volume Predicts Pulmonary Hypertension in Sarcoidosis

Abstract Rationale Pulmonary sarcoidosis, a complex disease with multiple parenchymal and vascular abnormalities, presents with pulmonary hypertension (PH) in 2-10% of patients, increasing to 50-70% with persistent dyspnea or parenchymal fibrosis 1. CT chest studies are commonly obtained, as opposed to cardiac catheterizations (RHC) which are more invasive and less accessible. Quantitative CT analysis of small (BV5) and large (BV10) vessels (as defined by a diameter of less than 5mm2 and greater than 10mm2) has been used to predict PH in other lung diseases 2-5. Decreased BV5 and increased BV10 as a fraction of total lung vessel volume (TBV) are associated with PH and parenchymal disease, but this has not been examined in sarcoidosis 2-5. We aimed to differentiate vascular pruning from parenchymal changes and determine if these measurements predict PH in sarcoidosis. Methods We included patients with pulmonary sarcoidosis who underwent a RHC and analyzed noncontrast CT chest scans within a year of RHC using AView qCT software. Lung texture and vessel volume analysis were performed. PH was defined by a mean pulmonary arterial pressure (mPAP) 20 and a PVR 3WU. Receiver operating characteristic (ROC) curves and logistic regression were used to evaluate associations between quantitative CT measurements and PH. Results We identified 58 patients with pulmonary sarcoidosis, 40 with PH and 18 without. BV5/TBV was significantly lower in the SAPH group (0.39 +/- 0.1 vs 0.44 +/- 0.07, p 0.05). Parenchymal involvement also differed significantly (34.2% +/- 26.5% vs 21.2% +/- 19.6%, p 0.05). ROC curve analysis showed both BV5/TBV (AUC 0.68, p = 0.01) and parenchymal involvement (AUC 0.65, p = 0.04) effectively predicted PH. BV5/TBV cut-off of 0.42 predicted PH with 72.2% sensitivity and 67.5% specificity. Abnormal lung texture cut-off of 29.5% predicted PH with 57.5% sensitivity and 72.2% specificity. A logistic regression model showed both BV5/TBV and abnormal lung parenchymal changes were independent predictors of PH (OR 6, 95% CI 1.6-22, p = 0.007 and OR 4, 95% CI 1.1-15, p = 0.038) respectively. Conclusion This retrospective analysis shows that the degree of vascular pruning (measured by BV5/TBV) and parenchymal involvement independently predict PH in patients with pulmonary sarcoidosis. There may be multiple mechanisms contributing to the development of PH in this population. This abstract is funded by: None