Significance of Syncope at Presentation among Patients with Pulmonary Emboli

Abstract Patients with intermediate-risk pulmonary emboli (PE) present a challenging clinical problem. While syncope has been suggested as a marker for adverse outcomes in these patients, data remain scarce. We aimed to investigate the clinical outcomes of intermediate risk PE patients presenting with syncope. We performed a retrospective cohort study comprised of consecutive, normotensive, PE patients, with evidence of right ventricular involvement. The primary outcome of major adverse clinical events (MACE) included either one or a combination of: mechanical ventilation, hemodynamic instability and need for inotropic support, reperfusion therapy, and in-hospital mortality. Secondary outcomes included: each of the above individual components including major bleeding and renal failure. Overall, 212 patients were evaluated, 40 (19%) presented with syncope, and had a higher prevalence of MACE (29% vs 9.4%, p=0.003), as well as each of the individual secondary endpoints: mechanical ventilation (10% vs 1.8%, p=0.026), hemodynamic instability (18% vs 2.9%, p=0.02), increased need of inotropic support (10% vs 0.6%, p=0.005), and bleeding (15% vs 2.4%, p=0.004). The prevalence of in-hospital mortality was very low (0.5%) with no significant difference between those with and without syncope. There was no significant difference in the need for reperfusion therapy. Upon multivariable analysis, syncope was found to be an independent predictor of adverse clinical outcomes (OR 3.8, C.I 1.48-9.76, p=0.005). In conclusion, among intermediate-risk PE patients with RV involvement, the presence of syncope is associated with a more complicated in-hospital course.