Biomarkers Associated with Major Bleeding in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is associated with a five-fold increased risk of thromboembolisms, mainly stroke, independently of other risk factors. Accurate assessment to balance the risk of stroke and systemic embolic events (S/SEE), against the risk of major bleeding is therefore an important therapeutic goal in the clinical management of these patients.

Age, prior hemorrhage, severe renal disease, and anemia (hemoglobin) have been independently associated with an increased risk of major bleeding in patients with AF. The use of different combinations of these mainly clinical variables has resulted in at least five validated risk scores for better prediction of bleeding events in patients with AF.


Medical Scientists at Uppsala University (Uppsala, Sweden) explored associations between a wide range of biomarkers and bleeding risk in patients with AF on oral anticoagulants (OAC). Biomarkers were analyzed in a random sample of 4,200 patients, 204 cases with major bleedings. The replication cohort included 344 cases with major bleeding and 1,024 random controls.

The plasma concentrations of high-sensitivity cTnT-hs, NT-proBNP, and GDF-15 were determined by Roche immunoassays using a Cobas Analytics e601 (Roche Diagnostics, Rotkreuz, Switzerland). Interleukin 6 (IL-6) was analyzed using the high-sensitivity sandwich ELISA immunoassay (R&D Systems Inc, Minneapolis, MN, USA) and Cystatin C with the ARCHITECT system ci8200 (Abbott Laboratories, Abbott Park, IL, USA) using the particle-enhanced turbidimetric immunoassay (PETIA) from Gentian Diagnostics ASA (Moss, Norway).

The proteomic analyses were performed with the high-throughput Proximity Extension Assay (PEA) technique using the Target 96 Multiplex CVD II, CVD III, and Inflammation panels (Olink Proteomics, Uppsala, Sweden), which together simultaneously measured 276 selected proteins in plasma potentially related to CVD and inflammation. The PEA technology uses pairs of antibodies equipped with DNA reporter molecules When binding to their correct targets, antibody pairs give rise to new DNA amplicons each ID-barcoding their respective antigens. The amplicons are subsequently quantified using the Fluidigm BioMark HD real-time PCR platform (Fluidigm, South San Francisco, CA, USA).

The investigators reported that out of 268 proteins, nine biomarkers were independently associated with bleeding in both cohorts. In the replication cohort a significant linear hazard ratios per interquartile range were confirmed for these biomarkers: cytokine GDF-15, cTnT-hs, osteopontin (OPN), ephrin type-B receptor 4 (EphB4), TNF-R1, TNF-R2, soluble urokinase plasminogen activator receptor (suPAR), TRAIL-R2, and osteoprotegerin (OPG).

The authors concluded that in patients with AF on OAC, GDF-15, cTnT-hs, and seven novel biomarkers were independently associated with major bleedings and reflect pathophysiologic processes of inflammation, apoptosis, oxidative stress, vascular calcification, coagulation, and fibrinolysis. Investigations of the utility of these markers to refine risk stratification and guide the management of patients at high risk of bleeding are warranted. The study was published on the November 2021 issue of the Journal of Thrombosis and Haemostasis.

Related Links:
Uppsala University
Roche Diagnostics
R&D Systems
Abbott Laboratories
Gentian Diagnostics
Olink Proteomics
Fluidigm