Trends in CT Pulmonary Angiography Use for Suspected Pulmonary Embolism

Quick Takes

  • Despite clinical decision rules designed to limit the use of CT pulmonary angiography (CTPA) in patients with suspected pulmonary embolism (PE), the rate of CTPA utilization in the emergency department has increased.
  • The increased use of CTPA was associated with more PE diagnoses overall and a higher proportion of patients with low-risk PE.

Study Questions:

Following the validation of clinical decision rules to avoid unnecessary computed tomography pulmonary angiography (CTPA) in emergency department (ED) patients with suspected pulmonary embolism (PE), has there been a decrease in the rate of CTPA utilization?


This retrospective analysis evaluated patients with suspected PE in 26 EDs in six European countries, and examined the temporal trends of CTPAs performed each year adjusted to an annual census, using the first 7 days of each odd month between 2015 and 2019. Secondary analyses included the number of diagnosed PEs, the proportion of patients with low-risk PEs, and the proportion of PE patients managed in ambulatory care or the intensive care unit (ICU).


There were 8,970 patients with CTPA included (56% female; median age 63 years). There was an increase in the use of CTPA between 2015 and 2019 (836 vs. 1,112 per 100,000 ED visits, p < 0.001), with more PEs diagnosed (138 vs. 164 per 100,000 ED visits, p = 0.03), and more low-risk PEs (annual percent change, +13.8%; 95% confidence interval [CI], 2.6-30.1%). There was increased ambulatory care management (annual percent change, +19.3%; 95% CI, 4.1-45.1%) and fewer admissions to the ICU (annual percent change, -8.9%; 95% CI, -17.1 to -0.3%).


Despite validated clinical decision rules to limit unnecessary CTPA in ED patients with suspected PE, the rate of CTPA increased in this study population, with a higher rate of PEs diagnosed, and an increased rate of low-risk PE findings.


While CTPA is a valuable diagnostic tool in patients with suspected PE, there are concerns about the risks of its overuse, including the risks from contrast and radiation, as well as the potential risk of anticoagulation in cases of false-positive or incidental findings. Several clinical decision rules have been developed to identify patients appropriate for chest imaging, which would be expected to reduce the rate of CTPA imaging in ED patients with suspected PE. Clinical trials utilizing these rules have reported reduced use of CTPA. However, in contrast to these clinical trial findings, this retrospective study found that CTPA utilization in the ED increased between 2015 and 2019, with increases in the number of diagnosed PEs and low-risk PEs. These results suggest that the real-world application of these clinical decision rules may not match findings from clinical trials. Whether these findings are due to a reluctance of providers to avoid imaging when the clinical decision rules suggest imaging is not needed is unclear. Future studies would be helpful to validate these findings and to explore the real-world application of clinical decision rules such as these.

Clinical Topics: Anticoagulation Management, Cardiovascular Care Team, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Vascular Medicine, Interventions and Imaging, Interventions and Vascular Medicine, Angiography, Computed Tomography, Nuclear Imaging

Keywords: Ambulatory Care, Angiography, Anticoagulants, Computed Tomography Angiography, Diagnostic Imaging, Emergency Service, Hospital, Intensive Care Units, Pulmonary Embolism, Tomography, X-Ray Computed, Vascular Diseases

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