Major bleeding in patients with pulmonary embolism presenting with syncope

Introduction Syncope has been shown to be a risk factor of bleeding in patients receiving thrombolytic therapy for acute pulmonary embolism (PE). Whether syncope predicts bleeding in a broader population of patients with PE remains unknown. Methods We used the RIETE registry data to assess whether initial presentation with syncope could predict bleeding in PE patients receiving anticoagulant therapy, and to explore the association between presence of syncope and timing and site of major bleeding events. Results Among 45,765 patients with acute PE from March 2001 to January 2021, 6760 (14.8%) had syncope. Patients with syncope were older and more likely to have hypotension, tachycardia, hypoxaemia or elevated troponin levels than those without syncope. They also were more likely to receive thrombolytics. During the first 90 days, 1097 patients (2.4%) suffered major bleeding (gastrointestinal 335, hematoma 271 and intracranial 163) and 3611 died (158 had fatal bleeding). Patients with syncope had a higher rate of major bleeding (odds ratio [OR]: 1.63; 95% CI: 1.41-1.89) and a nonsignificantly higher rate of fatal bleeding (OR: 1.47; 95% CI: 0.99-2.17) than those without syncope. Multivariable analysis confirmed that patients with syncope were at increased risk for major bleeding (adjusted hazard ratio [aHR]: 1.34; 95% CI: 1.15-1.55). On sensitivity analysis, the increased risk for major bleeding was confirmed in patients initially receiving anticoagulant therapy without thrombolytics at 7 days (aHR: 1.47; 95% CI: 1.13-1.91) and 90 days (aHR: 1.33; 95%CI: 1.13-1.56). Discussion Syncope is a predictor of major bleeding events in patients with PE, even among those receiving anticoagulation monotherapy.