Ministry of Health and Long-Term Care of Ontario.

because of supratherapeutic INRs on the day of surgery or failure to discontinue bridging therapy. Continued warfarin reduced clini-cally significant device-pocket hematoma, hematoma prolonging hospitalization, and hematoma requiring interruption of anticoagu-lation; hematoma requiring further surgery was borderline signifi-cant (Table). In planned subgroup comparisons, the primary outcome did not differ by antiplatelet agent or device surgery (new ICD, new pacemaker, pulse-generator change only, or pulse-gener-ator change with additional procedure) (P ≥ 0.61 for interactions). Conclusion In patients at moderate-to-high risk for thromboembolic events, continued warfarin therapy at the time of pacemaker or implantable cardioverter-defibrillator surgery reduced clinically significant device-pocket hematoma compared with bridging heparin