The role of high-sensitivity C-reactive protein, interleukin-6 and cystatin C in ischemic stroke complicating atrial fibrillation.

This study examined the role of high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6) and cystatin C in ischemic stroke complicating atrial fibrillation (AF) and the relationship of systemic inflammation with this disease in order to identify AF patients who are at high risk of stroke and need optimal anticoagulant therapy. A total of 103 AF patients, simple (n=75) or complicated by ischemic stroke (n=28), and 112 control subjects were recruited. IL-6 level was detected by using enzyme linked immunosorbent assay. Cystatin C and hsCRP levels were measured by means of a particle-enhanced immunonephelometric assay. The results showed that the AF patients had higher levels of hsCRP (P=0.004), IL-6 (P=0.000), and cystatin C (P=0.000) than control subjects. Plasma hsCRP level was increased in the AF patients with ischemic stroke as compared to the patients with simple AF (P=0.036). The AF patients who had the level of hsCRP exceeding 3.83 mg/L were at a higher risk than those with hsCRP level lower than 3.83 mg/L (P=0.030). After adjusting for other factors, cystatin C remained positively associated with IL-6 (r=0.613) and hsCRP (r=0.488). It was concluded that hsCRP is positively correlated with ischemic stroke complicating AF and may be a risk factor independent of other risk factors for AF. Elevated cystatin C level is also indicative of the increased risk of AF.