In 103 patients with AF assessed off anticoagulation (age: 71.0 [65.0–76.0] years; CHA2DS2-VASc score: 4.6 ± 1.7), we measured endogenous thrombin potential (ETP), plasma fibrin clot permeability (Ks, a measure of clot density) and clot lysis time (CLT) and other hemostatic parameters, along with GDF-15, NT-proBNP, and cTnI-hs. This evidence concerns the gene NPPB and atrial fibrillation.