P.3. Basic Science, Sudden Death Risk Stratification and Ventricular Arrhythmias: P.3.1 Is There an Interaction Between Active Inflammatory Process and Prothrombotic State in Patients with Chronic Atrial Fibrillation?

C-reactive protein (CRP) levels have recently been shown to be elevated in patients with chronic atrial fibrillation (AF), suggesting an inflammatory process that may be involved in the genesis and maintenance of AF. Also previous studies provided evidence of the presence of a prothrombotic state in patients with AF. The aim of this study was to evaluate the relationship between CRP and fibrinogen, d-dimer levels in chronic AF.

CRP, fibrinogen and d-dimer levels were measured in 127 patients with chronic AF (AF group) and 130 healthy subjects with sinus rhythm (control group). Mean age of the AF group was 65±11years old, 45 males. Seventy-two patients had non-valvular AF and 55 had valvular AF. Patients with acute coronary syndrome and chronic pulmonary, hepatic, renal, inflammatory diseases were excluded from the study. All data were expressed as mean±SE.

Age-adjusted CRP, fibrinogen and d-dimer levels were significantly higher in AF group when compared to the control group of patients in sinus rhythm (1.75±0.29 vs 0.33±0.02 mg/dl, p<0.001 for CRP, 432±12 vs 271±7.4 mg/dl, p<0.001 for fibrinogen, 1.14±0.17 vs 0.28±0.04 mg/dl, p<0.001 for d-dimer, respectively). A significant positive correlation was found between CRP and fibrinogen levels in AF group (r=0.465, p<0.001). Also, the levels of CRP and d-dimer showed a weak but statistically significant correlation in AF group (r=0.225, p=0.011). When fibrinogen and d-dimer levels were examined by CRP quartiles in AF group, patients that had CRP levels at the highest quartile (mean CRP level 5.15±0.92 mg/dl, n=32) had significantly higher fibrinogen and d-dimer levels compared to those at the lowest quartile (mean CRP level 0.19±0.01 mg/dl, n=31)(542±25 vs 330±15 mg/dl, p<0.001 for fibrinogen, 2.14±0.17 vs 0.48±0.11 mg/dl, p=0.006 for d-dimer, respectively). No significant difference was found in CRP, fibrinogen, d-dimer levels between non-valvular and valvular AF patients.

Elevated CRP levels in chronic AF support the proposal that an inflammatory mechanism is implicated in the pathogenesis of AF. Patients with AF and higher CRP levels have also higher fibrinogen and d-dimer levels. These results suggest an interaction between active inflammatory process and prothrombotic state in this group of patients. Further studies are required to establish the predictive value of the combination of these markers for thromboembolic risk stratification in patients with chronic AF.