A circulating biomarker risk-prediction model correlates with CHADS-2 risk score in chronic atrial fibrillation

Background: Inflammation and oxidative stress have been linked to the origin and persistence of atrial fibrillation (AF). CHADS-2 scoring system is a risk stratification schema well validated in prognostication of stroke in AF. We evaluated the association of markers of oxidative stress and inflammation with CHADS-2 scores in chronic AF patients. Methods: CHADS-2 scores were calculated for 64 subjects with chronic AF. Serum markers of inflammation [C-reactive protein (hs-CRP), interleukin-6 (IL-6), interleukin 1β (IL-1β), tumor necrosis factor-α (TNF-α)] and of oxidative stress [derivatives of reactive oxygen metabolites (DROMs) and isoprostanes (IsoPs)] were measured. Results: Twenty subjects were categorized as 0 (no risk), 24 as 1 (intermediate risk) and 20 as 2 (severe risk) based on their CHADS-2 scores. High sensitivity-CRP (CHADS-2 0 = 40.0%, 1 = 70.0%, 2 = 90.0%; p = 0.003) and DROMs (CHADS-2 0 = 45%, 1 = 78%, 2 = 80%; p = 0.04) were positively associated with the CHADS-2 risk score. Subjects with intermediate to severe CHADS-2 risk retained significant associations with abnormal hs-CRP (OR: 5.3, 95%CI: 1.1–25.0) and DROMs (adjusted OR: 6.7, 95%CI: 1.2–38.8) after adjusting for gender and hypertension. In a multiple logistic interaction model, there was no significant interaction between hs-CRP and DROMs in their association with CHADS-2 risk categories (p = 0.64). A biomarker risk-model, combining hs-CRP and DROMs, correlated well with the CHADS-2 risk categories (r = 0.49, p < 0.001). Conclusions: A biomarker risk-model using a combination of hs-CRP and DROMs correlates well with CHADS-2 risk scores in chronic AF. Either or both of these markers may add predictive power to future stroke risk prediction models