Introduction There is limited information regarding long-term survival following Pulmonary Embolism (PE), and no data on survival of patients that have undergone CT Pulmonary Angiography (CTPA) but found to be thrombus negative. The positive rate of PE detection in patients undergoing CTPA is variable, ranging from 4.7–25.8% and there is a high reported incidence of incidental pathology discovered during this investigation. We sought to determine the comparative survival of patient undergoing CTPA that were thrombus positive compared with those without a PE. We also sought to determine the rate of PE detection and characterise the nature of incidental findings found in patients undergoing CTPA.
Methods We retrospectively reviewed data on all CTPA investigations conducted between April 2010 and April 2012. All abnormalities reported on CTPA were reviewed and compared with previous imaging from the last 6 months to determine if they were new findings. Follow-up investigations and out-patient attendances were obtained for all new findings reported on the index CTPA, and 2 year mortality rates were established from regional registry data.
Results Of the 1043 patients suitable for analysis, 241 (22.4%) were thrombus positive. The thrombus positive cohort consisted of 47.7% males compared with 40.7% in the thrombus negative group (difference 7.1% [-0.0 to 14.2, p = 0.52]). Survival at 2 years following CTPA was 67.6% in thrombus positive patients and 65.9% in thrombus negative patients with a hazard ratio of 0.96 (95% CI, 0.74 to 1.23, p = 0.721) (Figure). Incidental findings were detected in 51.1% of CTPA examinations including: consolidation/collapse (19.5%), effusion (16.7%), neoplasia (13.5%), lymphadenopathy (9.8%), heart failure (7.6%) and pulmonary nodules (6.6%). 47.7% of incidental findings were deemed significant as determined by the need for further follow-up of clinical intervention.