Syncope predicts major bleeding events in patients with pulmonary embolism

Syncope can be classified as noncardiovascular including neurally mediated (vasovagal and carotidsinus syndrome), orthostatic hypotension (druginduced, autonomic failure, volume depletion) and cardiovascular (structural cardiovascular diseases, arrhythmias, acute pulmonary embolism [PE]).1 Beyond shortness of breath, chest pain, hemoptysis and tachycardia, the occurence of syncope may indicate underlying acute PE. In patients with PE, transient loss of consciousness may either result from reflectory cardioinhibition and vasodilatation or may indicate hemodynamic impairment due to pulmonary vascular obstruction and acute right heart failure.2,3 Some previous studies suggest that syncope may be associated with worse outcomes including a higher risk of major bleeding in patients with acute PE.4 Treatment of acute PE is associated with a higher risk of bleeding events. Bleeding risk is modified by the type and intensity of antithrombotic therapy4 and patient characteristics including age, renal function, history of bleeding events and anaemia.5 Major bleeding in patients with acute pulmonary embolism is associated with an increased risk of death.5