Conclusion
Positive DD has a higher correlation with PE diagnosis than the clinical prediction score. DD assay, whether positive or negative, is therefore an invaluable test in assessment of patients with suspected PE and can help determine the need for tomographic imaging. The absolute DD is more useful than the age-adjusted value.
What’s known (What’s already known about the topic)
What’s new (What does this article add)
Introduction
Pulmonary embolism (PE) is associated with high mortality and morbidity1 and creates a high financial and efficiency burden on the healthcare system2. Diagnostic imaging with tomographic techniques – such as computed tomography pulmonary angiography (CTPA) or ventilation-perfusion (V/Q) scan with single emission computed tomography (SPECT) is expensive3. Early diagnosis has been shown to reduce mortality2. Thus, the use of clinical decision aids and blood tests may help reduce the resource and economic burdens on our health system.4 The high negative predictive value of D-dimer assays has been most useful for excluding the diagnosis of PE4-6, particularly for patients in the Emergency Department (ED)7, 8. However, many did not undergo imaging investigations and this needs to be taken into account. Our aim was to compare the ability of a positive DD level (both absolute and age-adjusted) to predict a positive result for PE on imaging and compare it with a conventional clinical risk score – to better justify use of expensive tomographic imaging.
Methods