Pulmonary Artery to Aorta Ratio by CT Can Predict the Clinical Outcome in Acute Decompensated Heart Failure

Background: Although previous studies indicated that the ratio of pulmonary artery (PA) to ascending aorta diameter (PA/Ao) is associated with pulmonary artery pressure, the significance of PA/Ao in heart failure (HF) is not fully investigated. Methods and Results: Among 761 consecutive patients who were admitted to our institution because of acute decompensated HF from 2011 through 2016, thoracic CT data during the hospital stay were obtained from 447 patients (75.8 ± 11.2 years old, male 62.2%). The diameters of PA and aorta were measured at the level of PA bifurcation. Multiple regression analysis revealed that age, gender, left atrial dimension and tricuspid regurgitation pressure gradient (TRPG) were independent determinants of PA/Ao. The subjects were divided into higher (H) and lower (L) PA/Ao groups by the median value (PA/Ao = 0.88). TRPG and LVEF were higher in H than L (H/L, TRPG, 36 ± 19/29 ± 11 mmHg, P < .0001; LVEF, 48 ± 16/45 ± 15 %, P = .04). In-hospital mortality was higher in H than L (H/L, 4%/0%, P = .0002). Kaplan-Meier analysis showed that composite endpoint of all cause death and HF re-hospitalization was significantly higher in H (P = .004, log-rank test). Cox-regression analysis showed that PA/Ao was independently associated with the composite endpoint even after adjusting for age, gender, BMI, LVEF, hemoglobin level, eGFR (P = .003). Conclusions: Increase of PA/Ao is associated with poor clinical outcome in HF.