Effect of renal function on whole blood and fibrin clot formation in atrial fibrillation patients on warfarin

Objective: Atrial fibrillation (AF) brings a risk of thrombosis, requiring oral coagulation, and is associated with renal impairment. The two processes may be linked, as altered fibrin clot structure is present in end-stage renal failure. We hypothesised that progressively deteriorating renal function is linked to altered whole blood and fibrin clot properties and fibrinolysis. Methods: Thrombogenesis and fibrinolysis in 200 warfarinised AF patients was assessed by thromboelastography (TEG), a micro-plate assay (MPA) and the international normalized ratio (INR). Renal function was determined by creatinine clearance and two versions of the estimated glomerular filtration rate (eGFR). Results: Two TEG indices independently reflecting thrombogenesis were linked to creatinine clearance (p?p?p?p?p?=?0.001). The INR was unrelated to any renal function index, and the CHA₂DS₂VASc score was unrelated to any index. Conclusion: In warfarinised AF patients, renal function is linked to whole blood clot and fibrin clot formation, structure and dissolution, but has no effect on the INR.

• Key messages

• Despite oral anticoagulation, patients with atrial fibrillation (AF) still suffer from stroke and venous thromboembolism.

• The effect of renal function in warfarinised patients with AF is unknown and may account for excess thrombosis and/or haemorrhage.

• Using two different laboratory methods, our data point to an effect of renal function on clot structure and function that is independent of an effect of warfarin.