Prognostic value of pulmonary artery diameter/aorta diameter ratio in patients with acute pulmonary embolism

Background The ratio of pulmonary artery diameter (PAD) to ascending aortic diameter (AoD) has been reported to be a prognostic marker in several lung diseases; however, the usefulness of this tool in patients with acute pulmonary embolism (APE) is unknown. Here, we aimed to determine the long-term prognostic value of the PAD/AoD ratio in patients with APE. Methods A total of 275 patients diagnosed with APE at our tertiary care center between November 2016 and February 2022 were included in the study. The patients were divided into two groups according to the presence of long-term mortality and their PAD/AoD ratios were compared. Results Long-term mortality was observed in 48 patients during the median follow-up of 59 (39–73) months. The patients were divided into two groups for analysis: group 1, consisting of 227 patients without recorded mortality, and group 2, consisting of 48 patients with documented mortality. A multivariate Cox regression model indicated that the PAD/AoD ratio has the potential to predict long-term mortality (HR: 2.9116, 95% CI: 1.1544–7.3436, p = 0.023). Analysis of the receiver operating characteristic curve revealed that there was no discernible difference in discriminative ability between the simplified pulmonary embolism severity index (sPESI) and PAD/AoD ratio (area under the curve [AUC] = 0.679 vs. 0.684, respectively, p = 0.937). The long-term predictive ability of the PAD/AoD ratio was not inferior to the sPESI score. Conclusions The PAD/AoD ratio, which can be easily calculated from pulmonary computed tomography, may be a useful parameter for determining the prognosis of APE patients.