Syncope in Pulmonary Thromboembolism: A Cross-Sectional Analysis of Risk Factors and the Prognostic Value of Syncope

Background/Objectives: This study investigated the frequency of syncope, factors associated with syncope, and the relationship between syncope and mortality in patients with pulmonary thromboembolism (PTE). Methods: This study was planned as single-center retrospective and cross-sectional research. The PTE diagnosis was confirmed by partial or complete filling defects in at least one branch of the pulmonary circulation seen on pulmonary spiral computed tomography angiography. Patients' demographic data, symptoms, location of pulmonary embolism, Simplified Pulmonary Embolism Severity Index (sPESI) risk group, European Society of Cardiology (ESC) risk group, in-hospital mortality rate, and 30-day mortality rate were recorded. The presence of syncope and associated factors as well as the relationship between syncope and mortality were investigated. Results: This study included 589 consecutive patients diagnosed with PTE. The mean age was 70 ± 15 years, and 58.7% of the patients were women. Syncope was detected in 12.4% of the patients. Female sex, pulse rate, thrombosis in the main pulmonary artery, and right ventricular dysfunction on an echocardiogram were more prevalent in the syncope group. In-hospital mortality was 2.1 times higher in the syncope group. Elevated troponin levels increased the occurrence of syncope by 4.9-fold, whereas the presence of thrombosis in the main pulmonary artery and signs of right ventricular failure increased syncope occurrence by 4.3- and 3.1-fold, respectively. Conclusions: In the presence of syncope, patients with pulmonary thromboembolism, embolism in the main pulmonary arteries, high troponin values, right heart failure, and a high sPESI risk group should be carefully assessed and closely monitored for mortality, and reperfusion therapy should be considered as necessary.