Massive Pulmonary Emboli and CT Pulmonary Angiography

Background: Massive pulmonary embolism (PE) is a devastating form of PE which usually results in acute right ventricular failure and death within 1-2 h. Objectives: To retrospectively assess pulmonary vascular, cardiac, pleural, and parenchymal findings on CT pulmonary angiography (CTPA) in patients with a diagnosis of massive PE (systolic blood pressure < 90 mm Hg, syncope and/or shock). Methods: In 33 consecutive patients with proven massive PE, hemodynamic severity was assessed by the extent of right ventricular dysfunction (RVD); diameter of the main pulmonary artery; the shape of the interventricular septum; and the extent of obstruction to the pulmonary arterial circulation (CT obstruction index). Results: Central pulmonary arteries were embolized in all patients. RVD was detected in all patients (94% of them had severe RVD); the diameter of the main pulmonary artery was wider than normal in 76% of the patients; the shape of the interventricular septum was abnormal in all patients, and the CT obstruction index was higher than or equal to 50% in 85% of the patients. Wedge-shaped pleural-based consolidation was the most common parenchymal abnormality (36%). Pleural effusions were seen in 26 patients (79%). Twenty-eight patients were alive, and only the use of thrombolytic therapy was found to be statistically significant. Conclusions: In patients with acute massive PE, embolization of the central pulmonary arteries, RVD and displacement of the interventricular septum are commonly seen with CTPA. A CT obstruction index of > 50% is commonly observed in massive PE. There was no association between CTPA findings and survival. Copyright (c) 2008 S. Karger AG, Basel