Is CTPA Enough to Rule Out VTE in High Prob Patients?

Patients with high pretest probability of PE and negative CTPA were false negatives 5.2% of the time. It may not be safe to withhold anticoagulation from these people without further testing in addition to CTPA.

J Thromb Haemost. 2016 Jan;14(1):114-20. doi: 10.1111/jth.13188. Epub 2015 Dec 14.

Multidetector computed tomographic pulmonary angiography in patients with a high clinical probability of pulmonary embolism.

Moores L1, Kline J2, Portillo AK3, Resano S4, Vicente A4, Arrieta P5, Corres J6, Tapson V7, Yusen RD8, Jiménez D5.

Author information:

1F. Edward Hebert School of Medicine, Uniformed Services University, Bethesda, MD, USA.

2Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.

3Department of Internal Medicine, Instituto Ramon y Cajal de Investigacion Sanitaria IRYCIS, Ramón y Cajal Hospital, Madrid, Spain.

4Radiology Department, Instituto Ramón y Cajal de Investigación Sanitaria IRYCIS, Ramón y Cajal Hospital, Madrid, Spain.

5Respiratory Department, Instituto Ramón y Cajal de Investigación Sanitaria IRYCIS, Ramón y Cajal Hospital, Alcala de Henares University, Madrid, Spain.

6Emergency Department, Instituto Ramón y Cajal de Investigación Sanitaria IRYCIS, Ramón y Cajal Hospital, Madrid, Spain.

7Divisions of Pulmonary and Critical Care Medicine, Cedars-Sinai, Los Angeles, CA, USA.

8Divisions of Pulmonary and Critical Care Medicine and General Medical Sciences, Washington University School of Medicine, St Louis, MO, USA.

Abstract

Essentials: When high probability of pulmonary embolism (PE), sensitivity of computed tomography (CT) is unclear. We investigated the sensitivity of multidetector CT among 134 patients with a high probability of PE. A normal CT alone may not safely exclude PE in patients with a high clinical pretest probability. In patients with no clear alternative diagnosis after CTPA, further testing should be strongly considered.

SUMMARY:

Background: Whether patients with a negative multidetector computed tomographic pulmonary angiography (CTPA) result and a high clinical pretest probability of pulmonary embolism (PE) should be further investigated is controversial. Methods This was a prospective investigation of the sensitivity of multidetector CTPA among patients with a priori clinical assessment of a high probability of PE according to the Wells criteria. Among patients with a negative CTPA result, the diagnosis of PE required at least one of the following conditions: ventilation/perfusion lung scan showing a high probability of PE in a patient with no history of PE, abnormal findings on venous ultrasonography in a patient without previous deep vein thrombosis at that site, or the occurrence of venous thromboembolism (VTE) in a 3-month follow-up period after anticoagulation was withheld because of a negative multidetector CTPA result. Results We identified 498 patients with a priori clinical assessment of a high probability of PE and a completed CTPA study. CTPA excluded PE in 134 patients; in these patients, the pooled incidence of VTE was 5.2% (seven of 134 patients; 95% confidence interval [CI] 1.5-9.0). Five patients had VTEs that were confirmed by an additional imaging test despite a negative CTPA result (five of 48 patients; 10.4%; 95% CI 1.8-19.1), and two patients had objectively confirmed VTEs that occurred during clinical follow-up of at least 3 months (two of 86 patients; 2.3%; 95% CI 0-5.5). None of the patients had a fatal PE during follow-up. Conclusions A normal multidetector CTPA result alone may not safely exclude PE in patients with a high clinical pretest probability.

© 2015 International Society on Thrombosis and Haemostasis.

PMID: 26559176 [PubMed - in process]