The Significance of Syncope as a Presenting Symptom among Patients with Intermediate Risk Pulmonary Embolism

Background:
Pulmonary embolism (PE) can be a life threatening disease with wide spectrum of clinical symptoms posing a diagnostic and therapeutic challenge. We sought to investigate the prevalence and prognostic significance of syncope as a presenting symptom among patients with intermediate risk PE.

Methods:
We evaluated a total of 258 consecutive intermediate risk PE patients with evidence of right ventricular involvement presenting with syncope. We compared patients presenting with versus those without syncope for the endpoint of clinical deterioration during hospitalization mandating the need for escalation therapy defined as the need for either: mechanical ventilation, secondary reperfusion with thrombolysis or surgical embolectomy, or hemodynamic instability as well as severity findings of right ventricular involvement upon echocardiography.

Results:
Syncope was reported in 43 patients (17%). Those who presented with syncope were older (69±11.6 vs. 66±16.9, p=0.004), had a lower creatinine level (0.98±0.4 vs. 1.05±0.6, p=0.003), as well as BMI (28±4.9 vs. 30±7.2, p=0.015). Escalation therapy occurred in 12 patients (28%) in the syncope group and 17 patients (7.9%) in the non-syncope group (OR-3.3 C.I 1.4-7.6, p<0.001). The prevalence of moderate or severe RV dysfunction was significantly higher in the syncope group (OR-2.8, C.I 1.4-5.6, p=0.002). No significant difference was found in regards to the systolic pulmonary artery pressure as well as CT findings of interventricular septal shift and RV dilation.

Conclusion:
Syncope presentation is not uncommon among intermediate risk PE patients and is associated with a higher degree of RV dysfunction as well as a worse in-hospital clinical course mandating a greater need for escalation therapy.