Over 1.6 million pacing or cardioverter defibrillator (ICD) devices are implanted worldwide annually and up to 1/3 of this cohort have an indication for long-term anticoagulation therapy. Current guidelines suggest discontinuing the oral anticoagulant and initiating bridging therapy with heparin but this strategy is associated with increased costs, a short but high risk period of normal coagulability, and of itself is associated with a pocket haematoma rate of between 20 to 30%. Small case series have suggested that it may be safe to perform surgery without interrupting warfarin treatment but thus far no adequately powered prospective trial has reported on this strategy.
In the BRUISE-CONTROL study, 681 patients taking warfarin and requiring device implantation were randomly assigned in a 1:1 ratio to continued warfarin treatment or to bridging therapy with heparin. The primary outcome was clinically significant device-pocket haematoma, which was defined as device-pocket haematoma that necessitated prolonged hospitalization, interruption of anticoagulation therapy, or further surgery. The trial was terminated early after a prespecified interim analysis, which strongly favoured continuation of warfarin therapy. Clinically significant pocket haematoma occurred in 12 of 343 patients (3.5%) in the warfarin group, as compared with 54 of 338 (16.0%) in the heparin group (RR, 0.19; 95% CI, 0.10 to 0.36; P<0.001). Major surgical and thromboembolic complications were rare and did not differ significantly between the study groups. They included one episode of cardiac tamponade and one myocardial infarction in the heparin-bridging group and one stroke and one transient ischaemic attack in the warfarin group.
In this large multi-center prospective study, as compared with bridging therapy with heparin, a strategy of continued warfarin treatment at the time of pacemaker or ICD implantation significantly reduced the incidence of pocket haematomas.
- Birnie DH, Healey JS, Wells GA, Verma A, Tang AS, Krahn AD, Simpson CS, Ayala-Paredes F, Coutu B, Leiria TL, Essebag V. Pacemaker or Defibrillator Surgery without Interruption of Anticoagulation. N Engl J Med. 2013 May 9. [Epub ahead of print]