Impact of syncope and pre-syncope on short-term mortality in patients with acute pulmonary embolism

Syncope and pre-syncope are well-known symptoms of acute pulmonary embolism (PE). However, data about their impact on short-term mortality are scant. We assess the short-term mortality (30-day) for all-causes in PE patients admitted with syncope or with pre-syncope, according their hemodynamic status at admission.

Patients from the prospective Italian Pulmonary Embolism Registry (IPER) were included in the study. At admission, subjects were stratified according to 2008 ESC guidelines (as high- and non-high-risk patients).

Among the 1716 patients with confirmed acute PE, syncope or pre-syncope was the initial manifestation of the disease in 458 (26.6%) patients. Short-term mortality (30-day) for all causes were significantly higher in patients with syncope/presyncope (42.5% vs 6.2%, p < 0.0001) while PE patients with presyncope demonstrated a worst short-term outcome, in terms of mortality for all-causes, when compared to those subjects with syncope at admission (47.2% vs 37.4%, p = 0.03). A statistically significant difference in survival between pre-syncope and syncope was observed only in hemodynamically unstable patients [log rank p = 0.036]. Cox regression analysis confirmed that pre-syncope resulted an independent predictor of 30-day mortality in hemodynamically unstable patients at admission (HR 2.13, 95% CI 1.08-4.22, p = 0.029), independently from right ventricular dysfunction (RVD) (HR 6.23, 95% CI 3.05-12.71, p < 0.0001), age (HR 1.03, 95% CI 1.00-1.06, p = 0.023) and thrombolysis (HR 2.27, 95% CI 1.11-4.66, p = 0.025).

PE patients with syncope/presyncope had a higher 30-day mortality for all-causes as well as patients with presyncope had a worst short-term outcome when compared to PE patients with syncope. Moreover, hemodynamically unstable patients with presyncope had a worst prognosis independently from the presence of RVD, age, positive cTn and thrombolytic treatment.