Aims We aimed to clarify whether determination of levels of soluble CD40 ligand (sCD40L) could predict subsequent thrombo-embolic events in patients with non-valvular atrial fibrillation (NVAF). Methods and results Forty-four consecutive outpatients (mean age: 58 + 6 years, 20 male) with chronic NVAF who were not receiving aspirin and had no thrombus or spontaneous echo contrast (SEC) on left atrium (LA) or left atrial appendage (LAA) were included in the study. The patients had no history of

more »

... embolic event and were followed up 24 + 2 months for thrombo-embolic events. sCD40L was determined at the enrollment. All patients were evaluated by means of SEC and thrombus formation by transoesophageal echocardiography at the end of follow-up period. Twelve (27%) patients had SEC and 2 (5%) patients had thrombus on LAA. Ischaemic stroke occurred in 2 (4.5%) patients and transient ischaemic attack developed in 4 (9%) patients during follow-up. sCD40L was significantly higher in patients with LASEC (0.41 + 0.05 vs. 0.16 + 0.04 ng/mL, P ¼ 0.02) and embolic events (0.74 + 0.05 vs. 0.19 + 0.03 ng/mL, P ¼ 0.001) than in those without. sCD40L levels were significantly related to the LASEC grade (R ¼ 0.377, P ¼ 0.02). In multivariable analysis, while independent variables for SEC or thrombus formation were LA diameter, sCD40L levels, and the duration of AF, independent variables for cerebrovascular events were the existence of SEC or thrombus formation on LAA, and sCD40L level. Conclusion Plasma sCD40L may prospectively predict stroke in AF. sCD40L may provide useful marker to identify patients at high thrombo-embolic risk with NVAF.