Pulmonary Embolism Outcome: A Prospective Evaluation of CT Pulmonary Angiographic Clot Burden Score and ECG Score

Abstract

The purpose of this study was to establish whether a correlation exists between the CT pulmonary angiographic clot burden score, the ECG score at diagnosis, and the 12-month mortality rate among patients diagnosed with pulmonary embolism. A total of 523 consecutive patients who underwent CT pulmonary angiography for a suspected moderate to high pretest probability of pulmonary embolism were recruited from March 2003 to October 2004. There were 105 patients with positive CT pulmonary angiography examinations. Two consultant respiratory physicians and two consultant radiologists independently and prospectively calculated an ECG score and a quantified pulmonary artery clot burden, respectively. Twelve-month follow-up was completed in all patients. The mean ECG score was 2.36 (SD, 2.84) and the mean clot burden score percentage was 23.74% (16.8%). Poor correlation (r = 0.09) was seen between the average ECG score and the average clot burden score percentage (p = 0.39) at diagnosis. Thirteen patients had died at the 12-month follow-up. The mean ECG score for those patients who were alive was 2.4 (2.91) and for those who had died was 2.03 (2.34) at 12 months (p = 0.65). The mean clot burden score percentage for those patients who were alive was 24% (17%) and for those who had died was 22.1% (15.7%) at 12 months (p < 0.73). No statistically significant association was seen between ECG score and CT pulmonary angiographic clot burden at diagnosis and the 12-month all-cause mortality rate of patients diagnosed with pulmonary embolism.