Assessment of the association between pre-treatment and post-treatment left atrium size and severity of disease in patients with acute pulmonary embolism by using computed tomography pulmonary angiography.

Introduction: As far as we know, left atrium (LA) imaging findings of pre-treatment and post-treatment nonmassive, submassive and massive acute pulmonary embolism (APE) have not been reported in literature. The aim of this study is to assess LA sizes of nonmassive, submassive and massive APE before and after treatment with computed tomography pulmonary angiography (CTPA) and to research whether there are differences between groups.

Materials And Methods: Sixty two adult APE patients (21 nonmassive, 31 submassive and 10 massive) who were diagnosed with CTPA and who had post-treatment follow-up images and recorded clinical information were included in the study. Pre-treatment and post-treatment LA sizes of all groups were measured by two radiologists independently.

Result: The lowest pre-treatment LA size was found in massive APE and this difference was found to be statistically significant when compared with submassive (p= 0.001) and nonmassive (p< 0.001) groups. In addition, submassive APE patients were found to have lower LA size when compared with nonmassive APE patients (p= 0.006). In massive and submassive APE, post-treatment LA sizes were found to be statistically significantly higher when compared with pre-treatment (p< 0.001 for both groups). However, in nonmassive APE patients, pre-treatment and post-treatment LA size difference was not found to be statistically significant (p= 0.082).

Conclusions: As the severity of APE increases, LA size decreases. Thus, a decrease LA size during APE can show increased APE severity. This study reported that LA size increased statistically in post-treatment massive and submassive APE patients when compared with pre-treatment. These results suggest that in APE patients, as a response to treatment, LA size can be an additional parameter reflecting the changes in cardiac morphology.