Strategies to Reduce Advanced Imaging in Antenatal Pulmonary Embolism Diagnostics

Area of Science:

• Obstetrics and Gynecology
• Cardiology
• Radiology

Background:

• Advanced imaging for pulmonary embolism (PE) in pregnancy poses risks like radiation exposure and overdiagnosis.
• D-dimer testing and compression ultrasonography can help exclude PE and diagnose deep vein thrombosis (DVT), respectively, potentially reducing the need for advanced imaging.
• The utilization of these diagnostic strategies in community settings for antenatal PE remains unclear.

Purpose of the Study:

• To evaluate the use and diagnostic efficiency of D-dimer testing and ultrasonography for antenatal PE.
• To determine the number needed to test (NNT) to avoid advanced imaging for PE in pregnant individuals.

Main Methods:

• Retrospective cohort study across 21 US community hospitals (October 2021 - March 2023).
• Included pregnant patients suspected of PE who underwent D-dimer testing, compression ultrasonography, or advanced imaging.
• Analyzed avoidance of advanced imaging, NNT, and factors influencing test use via quasi-Poisson regression.

Main Results:

• D-dimer testing was used in 72.8% of 720 encounters. Low D-dimer values (<0.5 mg/L) avoided advanced imaging in 96.1% (NNT=2.3).
• Intermediate D-dimer values (0.5 to <1.0 mg/L) avoided advanced imaging in 45.8% (NNT=2.3).
• Compression ultrasonography was performed in 31.8%; DVT was diagnosed in 1.3%, avoiding advanced imaging in only 2 cases (NNT=115). Symptom-driven ultrasonography showed higher yield.

Conclusions:

• D-dimer testing is an efficient and safe method for antenatal PE diagnosis, with potential for wider application.
• Ultrasonography efficiency in this context was low, suggesting that a symptom-driven approach could enhance its utility.
• Optimizing the use of D-dimer and ultrasonography can improve antenatal PE diagnostics and reduce reliance on advanced imaging.