CHA2DS2-VASc score and fibrinogen concentration in patients with atrial fibrillation

Assessment of thromboembolic risk is crucial in choosing appropriate treatment in atrial fibrillation (AF). Current guidelines recommend basing the decision on the CHA2DS2-VASc score. However, the score is based only on clinical parameters and therefore its relationship with laboratory-assessed coagulation status might not always be objective. The aim of this study was to assess if the CHA2DS2-VASc score is associated with blood parameters in AF patients. Patients with continuous AF prequalified for catheter ablation were enrolled into the study and had CHA2DS2-VASc calculated and blood taken for coagulation parameters. The study population comprised of 266 patients (65.0% males; age 57.6 ±10.1 years). Patients were divided into those with CHA2DS2-VASc score 0, and those with ≥1 points, respectively requiring and not requiring anticoagulation treatment. The group with CHA2DS2-VASc = 0 (12% of patients) compared to those with CHA2DS2-VASc ≥ 1 had a significantly lower fibrinogen concentration (285.6 ±82.0 vs 322.6 ±76.4 mg/dL; p = 0.02). Partial thromboplastin time was not significantly different between groups (p > 0.05). Differences were noticed in parameters concerning red blood cells. Lower risk patients had a lower red blood cell count (4.9 ±0.4 vs 5.1 ±6.0 106/μL); p = 0.03), higher hemoglobin concentration (14.9 ±1.0 vs 14.3 ±1.4 g/dL; p = 0.04), and higher hematocrit (43.5 ±2.6 vs 41.7 ±4.7%; p = 0.001). It was observed that along with the increase in CHA2DS2-VASc score mean fibrinogen concentration increased (p-value for trend = 0.04). In summary, a higher CHA2DS2-VASc score is independently associated with an increase in fibrinogen concentration. Further research is needed to assess the value of fibrinogen in thromboembolic risk assessment.