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

Background: 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.

Methods: 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).

Results: 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).

Conclusions: 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.