Backgrounds: Paramount to guide the diagnostic strategy, the prevalence of pulmonary embolism in patients with syncope and no other symptoms is uncertain. We aimed to assess the pulmonary embolism prevalence in patients that present to the emergency department (ED) with syncope and no chest pain nor dyspnea.
Methods: Multicenter prospective cohort study in seven EDs in France. Adult patients who presented to the ED with syncope (transient loss of consciousness) were included. Patients with chest pain or dyspnea were excluded. Included patients underwent formal work-up for pulmonary embolism, including D-dimer testing and further imaging if positive. Cases of pulmonary embolism were adjudicated by two independent expert radiologists with the review of imaging studies. Secondary objectives included the pulmonary embolism prevalence in the subgroup of patients with cancer, in patients with negative Pulmonary Embolism Rule Out criteria (PERC) score, and according to the clinical probability assessed either by Wells or revised Geneva score.
Results: We analyzed 411 patients, in whom 128 (31%) underwent a computed tomographic pulmonary angiogram and 9 (2%) a ventilation-perfusion scan. A pulmonary embolism was confirmed in nine patients (prevalence of 2.2%, 95% confidence interval, 1.1-4.3%), including one subsegmental pulmonary embolism. This prevalence was of 18% (3-52%) in patients with cancer and 0.7% (0.1-4%) in PERC negative patients.
Conclusion: In our sample of patients with isolated syncope, the prevalence of pulmonary embolism was 2.2%. This value is not sufficiently low to negate the requirement for a formal work up in the ED, even in the absence of chest pain or dyspnea. However, the large confidence interval precludes any strong conclusion.