Although pulmonary embolism (PE) occasionally presents with syncope, patients with syncope are infrequently assessed for PE. In this prospective study from Italy, researchers determined the prevalence of PE in 560 elderly adults (mean age, 76) who were hospitalized for their first episode of syncope. Those excluded from the study included pregnant women and patients taking anticoagulants.
Each patient underwent D-dimer testing and Wells score calculation (in addition to standard syncope work-up); those with positive D-dimer results OR high-probability Wells scores underwent pulmonary computed tomography (CT) angiography or ventilation-perfusion lung scanning.
41% of patients had either an elevated D-dimer or a high-probability Wells scores and 97 of these patients (17% of the entire cohort) had a PE. PE was diagnosed in 25% of patients with unexplained syncope but also in 13% of patients with other potential explanations. A high thrombotic burden was not universal in patients with PE and syncope. One third of patients with a PE had a subsegmental PE, which was not likely to have caused syncope.
This study evaluated mainly elderly patients hospitalized for syncope (mean age of patients was 76 years). A PE was identified in 1 in 7 of these patients but was not necessarily the cause of syncope. Nevertheless, a high-sensitivity D-dimer and clinical assessment of VTE is warranted in this population.