Syncope on presentation is a surrogate for submassive and massive acute pulmonary embolism

Introduction: There are conflicting data regarding the prognostic value of syncope in patients with acute pulmonary embolism (APE). Methods: We retrospectively reviewed data of 552 consecutive adults with computed tomography pulmonary angiogram-confirmed APE to determine the correlates and outcome of the occurrence of syncope at the time of presentation. Results: Among 552 subjects with APE (mean age 54 years, 47% men), syncope occurred in 12.3% (68/552). Compared with subjects without syncope, those with syncope were more likely to have admission systolic blood pressure < 90 mm Hg (odds ratio (OR) 5.788, P < 0.001), and an oxygen saturation < 88% on room air (OR 5.560, P < 0.001), right ventricular dilation (OR 2.480, P = 0.006), right ventricular hypokinesis (OR 2.288, P = 0.018), require mechanical ventilation for respiratory failure (OR 3.152, P = 0.014), and more likely to receive systemic thrombolysis (OR 4.722, P = 0.008). On multivariate analysis, syncope on presentation was an independent predictor of a massive APE (OR 2.454, 95% CI 1.109–5.525, P = 0.03) after adjusting for patients' age, sex, requirement of antibiotics throughout hospitalization, peak serum creatinine, admission oxygen saturation < 88% and admission heart rate > 100 bpm. There was no difference in mortality in cases with APE with or without syncope (P = 0.412). Conclusion: Syncope at the onset of pulmonary embolization is a surrogate for submassive and massive APE but is not associated with higher in-hospital mortality.