Abstract 17265: Pulmonary Arterial Enlargement on Computed Tomography is a Powerful Predictor of Mortality in Patients Undergoing Evaluation for Pulmonary Hypertension
Background: The pulmonary vasculature is readily visualized on chest computed tomography (CT) and CT-based measurements are associated with pulmonary hypertension (PH). We aimed to determine the prognostic value of these CT measurements in patients (pts) being evaluated for PH.
Methods: In 141 consecutive pts (age 59±15, 36% male) who underwent right heart catheterization (RHC) and chest CT for the evaluation of dyspnea and PH, we measured the diameters of the main pulmonary artery (mPA) and ascending aorta (Ao) in 651 transaxial CT scans and calculated their ratio mPA/Ao (ratio PA). Abnormal CT values were defined as mPA >30 mm and ratio PA >1; and Framingham Heart Study (FHS) sex-specific values of mPA >27 mm for women and >29 mm for men and ratio PA > 0.9. Using the WHO definition for PH, 89 (63%) pts were diagnosed with PH and 52 (37%) pts did not have PH. The primary endpoint was all-cause mortality. In a subset of 99 pts with serial CT scans (58 PH pts, 41 non-PH pts), we assessed the rates of progression of the CT measurements.
Results: Median follow-up was 6.5 years. Overall, there were 54 (38%) deaths: 40 (45%) in PH and 14 (27%) in the non-PH group. Table 1 shows the baseline RHC and CT measures in pts with and without PH. There was a 2-4 fold increase in hazard for mortality with abnormal mPA and ratio PA (hazard ratio, HR [95% CI]: mPA>30 of 3.0 [1.6-5.7]; sex-specific mPA of 2.4 [1.2-4.9]; ratio PA>1 of 2.5 [1.4-4.7]; FHS ratio PA>0.9 of 4.1 [1.6-10.3]; all p<0.02). In the subset of pts with serial CTs, the annualized rate of mPA diameter increase was 0.5 mm/yr in PH pts and 0.3 mm/yr in non-PH pts, but was not associated with higher mortality. The ratio PA did not change in non-PH pts, but did increase by 0.012/yr in PH pts, and was associated with a 2-fold increase in mortality (HR 2.2, [1.04-4.6], p=0.04) per 0.10 increase.
Conclusions: PA enlargement on CT predicts mortality in pts undergoing evaluation for PH and serial increase in the ratio PA is a marker of disease progression and prognosis in PH.
- © 2013 by American Heart Association, Inc.