Peri-Procedural Anticoagulation Protocol
Patients underwent ablation procedures in the left atrium under general anesthesia using standard techniques. Ablation practices, pre-procedure oral anticoagulant regimen, and screening of possible drug interactions were left to the discretion of the treating physician. If used, warfarin was administered before and after the procedure without interruption. If patients were receiving DOAC pre-procedure, they were held 0-2 doses before the procedure. Bolus doses of heparin were administered prior to, or immediately after transseptal puncture, either initially as one dose, or a divided dose before and immediately after transseptal access at the operator’s discretion. If the dose was divided, the combined administered dose was recorded as the bolus amount.
A departmental heparin protocol was initiated for left atrial ablation procedures based on published weight-based dosing protocols with an acceptable safety record.6 Patients received intravenous UFH with a goal to achieve and maintain an ACT> 300 seconds. The initial prescribed bolus dose was: 50 units/kg for patients receiving warfarin, 75 units/kg for patients not receiving oral anticoagulation, and 120 units/kg for patients receiving DOACs. An infusion of UFH was initiated at 10% of the bolus dose per hour. ACTs were to be drawn and analyzed (Hemochron Signature Elite, Werfen, Inc., Barcelona, Spain) every 15 minutes until therapeutic levels are reached. The protocol delineated that the first ACT was to be drawn 15 minutes after heparin administration. The time to first therapeutic ACT was measured from time zero to the first documented therapeutic ACT, where time zero was denoted in two methods; (A) from initial heparin administration, and (B) from transseptal puncture. Once a therapeutic ACT was established, repeat ACTs were drawn a minimum of every 30 minutes. Additional bolus doses and infusion rates were at the discretion of the operator. Ablation was not to be performed until a therapeutic ACT had been obtained. The usual care cohort was not guided by an institutional protocol, thus heparin bolus, infusion, and pre-procedure oral anticoagulation regimen were left to the discretion of the operator.
After the procedure was completed, sheaths were removed and hemostasis obtained by either manual pressure after heparin reversal with protamine, or figure of eight suture placement.7 In uncomplicated cases, oral anticoagulation was restarted or continued the evening after the procedure.