Heparin Dose in Non-valvular Atrial Fibrillation Patients Undergoing Left Atrial Appendage Closure Under Different Antithrombotic Management

Objective: To investigate the correlation between the heparin dose and activated clotting time (ACT) during left atrial appendage occlusion (LAAC) in patients with non-valvular atrial fibrillation (NVAF) under different antithrombotic management backgrounds and to provide evidence for the rational use of heparin in LAAC. Methods Patients with NVAF who underwent LAAC in our hospital from February 2017 to March 2021 were evaluated. The patients were grouped according to the type of antithrombotic therapy they received before LAAC and the international normalised ratio (INR) into the following groups: patients on antiplatelet drugs, patients on non-vitamin K antagonist oral anticoagulants, patients with a warfarin INR < 1.8, and patients with a warfarin INR ≥ 1.8. The heparin doses were 100, 100, 100, and 80 U/kg, respectively. To measure ACT, venous blood samples were collected at 15 minutes after administering the drug. Results The study enrolled 435 patients, comprising 135, 155, 107, and 78 in the antiplatelet drug, non-vitamin K antagonist oral anticoagulant, warfarin INR < 1.8, and, warfarin INR ≥ 1.8 groups, respectively. At baseline, the proportion of patients with coronary heart disease was significantly lower in the warfarin INR < 1.8 group than in the other three groups ( p   0.05). The heparin dose was significantly lower in the warfarin INR ≥ 1.8 group (80.25 ± 2.84 U/kg) than in the other three groups ( p   0.05). LAAC was completed in all 435 patients without perioperative bleeding or thromboembolic complications. Conclusions For patients not taking warfarin or with an INR < 1.8 on warfarin before LAAC, it is reasonable to use heparin at a dose of 100 U/kg. It is safe and effective to reduce the heparin dose by 20% in patients with an INR ≥ 1.8.