Screening for Pulmonary Embolism in Patients with Sickle Cell Disease

For patients with sickle cell disease (SCD), the Wells’ Criteria for Pulmonary Embolism demonstrated acceptable clinical efficacy for screening patients at greater likelihood of pulmonary embolism (PE), according to a study.

“Individuals living with SCD are at an increased risk of venous thromboembolism (VTE) including PEs. There is a high mortality associated with PE in individuals with SCD,” wrote the authors of this study, which was published as a research letter in the British Journal of Haematology.

The authors added, “It can be difficult to diagnose PE since presenting symptoms of PE often mimic those of other forms of vaso-occlusive crisis in SCD. Currently, there are no validated models for predicting PEs in patients with sickle cell disease, which often leads to frequent computed tomography (CT) scans and exposure to harmful radiation and intravenous contrast.”

In this study, the investigators sought to evaluate potential clinical biomarkers that may be predictive of PE among patients with SCD. A retrospective chart review was conducted, comprising 349 patients who underwent PE testing including a CT scan of the chest. To obtain a parsimonious model of PE predictors, the researchers conducted forward and backward stepwise model selection.

The overall incidence of PE in this population was 9.7%. Out of the factors evaluated, the researchers identified the Wells’ Criteria for PE as having the greatest clinical significant for predicting PE in this population. A Wells score of greater than 4 was found to be associated with a sensitivity and specificity of 72.5% and 70.1%, respectively, for predicting PE. A score of 6 or more was 50% sensitive and 87% specific for predicting PE.

“The Wells score is an acceptable clinical tool which may prove useful in individuals with SCD to predict who is most likely to have a PE and therefore should undergo a CT scan,” wrote the authors in conclusion. “A prospective study is needed to further confirm these findings.”