Table 1.
Biomarkers selected for analysis
| Biomarker | Description | Reference range |
|---|---|---|
| D‐Dimers (ELISA) | A fibrin degradation product ‐ a small protein fragment present in the blood after a blood clot is degraded by fibrinolysis. Measured ELISA and a highly sensitive assay. | 0–400 ng/ml |
| D‐dimers (Innovance) | As above, but near‐patient testing and fast turn‐around time allows for day to‐day use. This point of care test was used by many routine laboratories in the UK in 2016. | 0–1.13 mg/l |
| Plasmin‐antiplasmin complexes | An ELISA assay that measures the level of plasmin‐antiplasmin complexes and thus is a very sensitive assay of plasmin activation. | 150–800 μg/l |
| Prothrombin fragment 1 + 2 | A small molecule cleaved from prothrombin when thrombin is generated. It is thus a sensitive marker of thrombin generation i.e. coagulation turnover. It is an ELISA assay | 200–1200 pmol/l |
| Thrombin Generation | Thrombin generation can be measured dynamically using the ETP, a term introduced by Hemker in 1986 that refers to the total amount of thrombin generated during the test. Commonly measured variables when analysing thrombin generation include the Lag Time, the Time to Peak Thrombin Generation, the ETP ‐ the area under the curve. |
Lag Time: 0.9–3.4 min ETP: 696–1533 nmol/l*min Peak: 103–475 nmol/l Time to Peak: 1.4–7.7 min |
| Prothrombin time | A routine measure of the extrinsic pathway of coagulation, used to determine the clotting tendency of blood. | 11.7–15.9 s |
| Activated partial thromboplastin time | A routine measure of the intrinsic and common coagulation pathways, used to detect abnormalities in blood clotting. | 27–52 s |
| Clauss fibrinogen | A functional measure of fibrinogen | 2.03–4.11 g/l |
| Soluble Tissue Factor | A marker of tissue factor activation ‐ when tissue factor is upregulated part of the molecule may be cleaved and enters the systemic circulation. | 40–300 pg/ml |
| Troponin I | Part of the troponin complex in cardiac muscle tissue, used to detect myocardial damage resulting from myocardial ischaemia or non‐cardiac causes, such as PE. | 0.91–2.63 ng/ml |
| B‐type natriuretic peptide | A polypeptide secreted by the ventricles of the heart in response to excessive stretching of heart muscle cells, used to measure heart strain resulting from primary heart disease or noncardiac causes such as PE. | 107–523 pg/ml |
| C‐ reactive protein | CRP is an acute‐phase protein, the levels of which rise in response to inflammation. Elevation of CRP has been shown to be associated with a diagnosis of PE. | 0–3104 ng/ml |
| MRproAMP | MRproANP is an emerging measure of right ventricular strain which occurs as a consequence of pulmonary embolism. | 0–954 pmol/l |
CRP, C reactive protein; ELISA, enzyme‐linked immunosorbent assay; ETP, endogenous thrombin potential; MRproANP, mid‐regional pro‐atrial natriuretic peptide; PE, pulmonary embolism.