Acute pulmonary thromboembolism is a life-threatening disease. Clinical suspicion is essential for diagnosis because of lack of a specific finding for diagnosis of PTE. The aim of this study is to investigate the relationship between the diagnosis and prognosis of alternative biomarkers such as SCUBE-1 and VAP-1 in the diagnosis of clinically suspected acute PTE.

Patients who were admitted to the Emergency Department and diagnosed as acute PTE were included in the study. Patients with acute ischemic disease, liver failure, renal failure, pregnancy, active malignancy and/or history of known PTE were excluded from the study. A control group was formed from healthy volunteers at similar age and sex. SCUBE-1 and VAP-1 levels were studied from serum samples taken from the patient and control groups. Data were analyzed using by IBM SPSS V23.

The definitive diagnosis of APT is made by ventilation/perfusion (V/Q) scintigraphy and thorax computed tomography angiography (CTA). There is no specific examination as a laboratory parameter. A definitive diagnosis cannot be made with d-Dimer, which is the most frequently used laboratory test today; it is used to exclude the diagnosis of APT.

The non-specificity of the clinical picture, the fact that the diagnosis depends on the experience of the physician and the necessity of exposure to radiation and contrast material for the definitive diagnosis has revealed the necessity of searching for alternative ways for the diagnosis of APT. "Signal peptide CUB-EGF domain-containing protein-1" (SCUBE-1) is a biomarker released during platelet aggregation, and "Vascular adhesion protein-1" (VAP-1) is a biomarker released from endothelium, and these biomarkers show promise for the diagnosis of APT.

Determination of serum SCUBE-1 and serum VAP-1 levels 5 mL blood taken from the peripheral veins of the patients was placed in a biochemistry tube and centrifuged at 3000 g. After centrifugation, the serum part of the blood was separated and taken into an eppendorf tube and stored in an ultra-deep freezer at minus 80°C until the study day. Before starting the study, the ELISA kits kept at 2-8°C and the samples kept in an ultra-deep freezer at minus 80°C were brought to room temperature.

Inclusion Criteria:

• being older than 18 years of age
• presenting to the emergency department,
• diagnosed with acute PTE by contrast-enhanced computed tomography angiography

Exclusion Criteria:

• having acute ischemic disease, liver, kidney or advanced heart failure, liver disease, pregnancy, active malignancy or hematological disease, and a known history of PTE.

Patients who applied to the emergency department of Samsun Ondokuz Mayis Universtiy between 01.01.2019 and 30.06.2019 and were diagnosed with acute pulmonary thromboembolism (APT) by contrast-enhanced thorax computed tomography were included in the study. A group of healthy volunteers with similar gender, age and exclusion criteria was formed with the patients with APT included in the study. Demographic data, clinical probability scores (Wells' criteria, revised Geneva score), simplified Pulmonary Embolism Severity Index (sPESI) and early mortality risk score (in 30 days) of the patients were recorded.