Value of syncope in patients with high-to-intermediate risk pulmonary artery embolism.

Background: Syncope may develop in 9-35% of patients with pulmonary embolism (PE). Despite its severity and importance, the prognostic value of syncope in PE is unclear. We aimed to assess the value of syncope in patients with high-to-intermediate risk PE.

Methods: A total of 117 patients (62 males and 55 females, median age 51,86 ± 13,4 years) were enrolled into the study. According to the presence of syncope at the onset of PE, all patients were divided into two groups: the syncope group (SG) comprised 35 patients (48.8 ± 15.5 years, male 54.3%) who experienced at least one syncopal episode. The remaining 82 patients (53.4 ± 12.6 years, male 42.7%) without syncope comprised the control group (CG).

Results: The main predisposing risk factors of PE were the same except fewer recurrent episodes of PE (8.5 vs. 24.5% in patients from SG (p=0.048). Clinical probability of PE according to the Revised Geneva and Wells scores was high almost in every second patient in both groups (p=NS). There were twice as many patients with a high risk of fatal outcome among patients with syncope in comparison with CG patients (45.7 vs. 25.6%, respectively, p=0.032). Massive PE on computed tomography scans was found again significantly more frequently in patients with syncope (60 vs. 39%, p=0.036). The vast majority (60%) of patients with a history of syncope were treated by thrombolytic therapy (21/35) vs. only 29% of patients without syncopal events (24/82; p=0.001). In-hospital mortality was higher in patients with syncope than the control group (14.2 vs. 8.5%, p=NS).

Conclusions: The history of syncope in patients with suspected PE should be considered as a possible criterion of high risk of fatal complications of in-hospital period due to frequent embolism of the pulmonary trunk and its main branches. The use of thrombolytic therapy showed a tendency in improving outcomes.