Aim: The aim of the present study was to assess the safety of cardiac rhythm device implantation during uninterrupted oral anticoagulant therapy.
Methods: Patients at high thromboembolic risk (venous thromboembolism <3 months, nonvalvular atrial fibrillation with CHADS2 score >2, valvular atrial fibrillation, prosthetic heart valves) underwent procedures during uninterrupted warfarin (on warfarin group) and were compared to low-risk patients who underwent procedures after warfarin withdrawal (off warfarin group). Primary endpoint was a composite of hematoma requiring warfarin interruption, reoperation, or blood transfusion; death; hemothorax; and tamponade. Secondary endpoints were nonsignificant hematoma and clinical arterial thromboembolism assessed at discharge and at a 2 month follow-up.
Results: One hundred and ninety-one patients were enrolled, 102 in the 'on warfarin group' and 89 in the 'off warfarin group'. The majority of procedures were first implants (73% in the 'on warfarin group' vs. 87% in the 'off warfarin group', P= 0.01). Pacemakers, implantable cardioverter defibrillators, and biventricular devices were included. International normalized ratio at implant was 2 ± 0.28 (range 1.6-3.2) in the 'on warfarin group' and 1.3 ± 0.19 (range 1-1.6) in the 'off warfarin group' (P= 0.0001). Incidence of hemathoma was five of 102 in the 'on warfarin group' vs. three of 89 in the 'off warfarin group' (5 vs. 3%, P = not significant) and all hemathomas resolved spontaneously. There were no significant hemathomas in either group. There was no death, hemothorax, or tamponade. There were no thromboembolic events at 2 months.
Conclusion: Cardiac rhythm device implantation during uninterrupted warfarin was not associated with increased bleeding compared with warfarin interruption.