van der Pol LM, et al. - In order to avoid radiation exposure during diagnostic imaging in pregnant women with suspected pulmonary embolism, the utility as well as the safety of a pregnancy-adapted algorithm was tested in this study. Findings revealed that the pregnancy-adapted YEARS diagnostic algorithm afforded a safe alternative to rule out pulmonary embolism across all trimesters of pregnancy. With the use of this tool, 32 to 65% of patients could escape computed tomographic (CT) pulmonary angiography.

Methods

• This was a prospective study involving pregnant women with suspected pulmonary embolism.
• Researchers evaluated three criteria from the YEARS algorithm (clinical signs of deep-vein thrombosis, hemoptysis, and pulmonary embolism as the most likely diagnosis) and measured the d-dimer level.
• To rule out pulmonary embolism, the condition was if none of the three criteria were met and the d-dimer level was less than 1000 ng per milliliter or if one or more of the three criteria were met and the d-dimer level was less than 500 ng per milliliter.
• Women with symptoms of deep-vein thrombosis had to undergo compression ultrasonography when the YEARS algorithm was adapted; CT pulmonary angiography was not performed among those who had positive results (ie, a clot was present).
• CT pulmonary angiography was performed in all patients in whom pulmonary embolism had not been ruled out.
• At 3 months, the incidence of venous thromboembolism was assessed ( primary outcome).
• They also estimated the proportion of patients in whom CT pulmonary angiography was not indicated to safely rule out pulmonary embolism (secondary outcome).

Results

• They screened 510 women and excluded 12 (2.4%) among those.
• At baseline, 20 patients (4.0%) received the diagnosis of pulmonary embolism.
• One patient received the diagnosis of popliteal deep-vein thrombosis (0.21%; 95% confidence interval [CI], 0.04 to 1.2) and none had pulmonary embolism during follow-up.
• In 195 patients had no indication for CT pulmonary angiography and thus it was avoided in these patients (39%; 95% CI, 35 to 44).
• The algorithm demonstrated highest efficiency during the first trimester of pregnancy and lowest efficiency during the third trimester; in 65% and 32% of patients who began the study in the first trimester and in the third trimester, respectively, CT pulmonary angiography was avoided.