Elevated 8-isoprostane tied to thromboembolic events in AF

Despite taking anticoagulant therapy, elevated levels of 8-isoprostane levels appear to increase the risk of thromboembolic events in patients with atrial fibrillation (AF), reports a recent study.

The study included 243 AF patients (median age 69 years, 44 percent women), in whom serum 8-isoprostane levels were measured using an enzyme-linked immunosorbent assay. Prothrombin markers assessed included plasma fibrin clot permeability, clot lysis time, endogenous thrombin potential, von Willebrand factor (VWF), and fibrinolytic proteins. All patients were on anticoagulation therapy.

Over a median 53 months of follow-up, 20 patients (8.4 percent) developed ischaemic cerebrovascular events at a rate of 1.9 percent per year. There were no cases of systemic thromboembolism.

Despite having comparable baseline demographic, comorbidity, and medication data, serum 8-isoprostane levels differed between those who did vs did not develop thromboembolic events (538 vs 362 pg/mL, respectively). Specifically, 8-isoprostane was elevated by nearly 50 percent in those who saw such events, a difference that was statistically significant (p=0.0094).

Simple Cox regression analysis confirmed that high 8-isopostane was correlated with thromboembolic events during follow-up (cut-off value 459 pg/mL: hazard ratio, 2.87, 95 percent confidence interval, 1.17–7.03; p=0.02).

“The study provides additional insights into complex links between enhanced oxidative stress and AF occurrence along with its clinical outcomes. Whether modulation of oxidative stress might reduce stroke risk in AF remains to be established,” the researchers said.