Altered fibrin clot properties and elevated von Willebrand factor are associated with progression to permanent atrial fibrillation: A cohort study.

Background: The role of a prothrombotic state in atrial fibrillation (AF) progression to permanent arrythmia (PerAF) is unclear. Formation of denser and poorly lysable fibrin clots has been observed in AF patients also with sinus rhythm in association with higher stroke risk. We investigated whether altered fibrin clot properties and other prothrombotic state markers may contribute to AF transition to PerAF.

Methods: In the cohort study, in 226 anticoagulated patients (median age 69 years, median CHA₂DS₂-VASc of 3) with paroxysmal (n = 83, 36.7%) or persistent (n = 143, 63.3%) AF, we assessed at baseline plasma clot permeability (K_s), clot lysis time (CLT), proteins involved in fibrinolysis and von Willebrand factor (vWF) antigen. We recorded patients with PerAF during a median follow-up of 58 months.

Results: During follow-up, PerAF was documented in 62 (27.4%, 5.7%/year) subjects, who had higher prevalence of heart failure, higher body mass index and longer history of arrhythmia. AF transition to PerAF was associated with 25.7% longer CLT in relation to 21.3% higher plasminogen activator inhibitor type 1, and 29% higher vWF compared to the remainder, with no differences in K_s, plasminogen or α2-antiplasmin. By multivariable analysis, CLT (per 10 min, odds ratio [OR] 2.734, 95% confidence interval [CI] 1.788-4.180, p < .001), vWF (per 10%, OR 1.352, 95% CI 1.145-1.596, p < .001) and heart failure (OR 2.637, 95% CI 1.008-6.900, p = .048) were associated with progression to PerAF.

Conclusion: Suppressed fibrin clot susceptibility to lysis and elevated vWF could contribute to progression to PerAF despite anticoagulation, which suggests links between blood coagulation and AF progression.