The Role of Pulmonary Artery Obstruction Index Ratio in Predicting Clinical Course in Pulmonary Embolism<span style="mso-bidi-font-weight: bold;">

Background/Objective: This study aimed to investigate the relationship between pulmonary arterial computed tomography obstruction index ratio (CTOI) and simplified pulmonary embolism severity index (sPESI), one of the clinical probability scoring modalities, in determining the severity of PE and to determine whether CTOI is a mortality marker. Methods: The study included 117 patients diagnosed with PE by Computed Tomography Pulmonary Angiography (CTPA). CTOI was determined according to the localization of the embolus and the obstruction caused by the embolus in the vessel. Patients were divided into groups according to sPESI. Patient deaths up to six months after PE diagnosis were recorded. Logistic regression analysis was performed to identify predictors of mortality. Results: According to sPESI classification, there was no difference in CTOI between high-risk and low-risk groups. After six months of follow-up, there was no difference in CTOI rate between the patients who died and those who survived. Conclusion Although CTPA is the gold standard for diagnosing PE, it would be more appropriate to use it together with clinical findings to determine the severity of the disease. Further evaluation is needed to investigate the usefulness of the obstruction index and CT findings of right ventricular dysfunction for classifying patient risk and determining therapeutic options.