Post-operative use of heparin increases morbidity of pacemaker implantation

Implantation of cardiac rhythm devices without interruption of oral anticoagulation compared with perioperative bridging with low-molecular weight heparin

BACKGROUND

Increasing numbers of patients requiring arrhythmia device implantation are taking warfarin. The common practice of warfarin interruption and perioperative bridging with heparin is associated with a high rate of postoperative hemorrhagic complications. We assessed the safety of device implantation without interruption of warfarin therapy.

METHODS

Three patient groups were studied: Group 1 consisted of 117 consecutive patients on long-term warfarin therapy with significant risk of thromboembolism (atrial fibrillation with CHADS(2) score > or =2, mechanical heart valve, recent venous thromboembolism) who underwent arrhythmia device implantation without interruption of warfarin. Group 2 was 117 patients who served as age- and sex-matched controls matched to procedure type not taking warfarin. Group 3 consisted of 38 similar thromboembolic risk historical control patients who underwent interruption of warfarin therapy and bridging with dalteparin before and 24 hours after surgery. Active fixation leads were used by subclavian or axillary vein puncture, with septal fixation in the ventricle in 56% of patients. Hemorrhagic and thromboembolic complications were assessed at discharge and at 7 and 30 days after surgery.

RESULTS

During an 18-month period, 1,562 consecutive adult patients underwent heart rhythm device implantation or replacement. One hundred seventeen of the 447 patients on warfarin were considered high risk and remained on warfarin for their procedure. The mean international normalized ratio in group 1 patients was 2.2 +/- 0.4 (age 79 +/- 11 years, 73 male). Significant hematoma was noted in 9 patients (7.7%), and one required surgical revision (0.9%). Five group 2 patients (control) had significant hematomas (4.3%), none of which required revision (P = .41). In group 3, 9 patients developed significant hematomas (23.7%, P = .012), 3 of whom required reoperation (7.9%, P = .046). There were no deaths, thromboembolic events, cardiac tamponade, or hemothorax in any patient. The only risk factor for hematoma in the warfarin patients was the number of leads implanted.

CONCLUSIONS

Arrhythmia devices can be implanted safely in patients with high thromboembolic risk without interruption of warfarin. This strategy may be associated with reduced risk of significant pocket hematoma compared with dalteparin bridging.

Perioperative anticoagulation in patients having implantation of a cardiac pacemaker or defibrillator: a systematic review and practical management guide

BACKGROUND

The perioperative management of anticoagulation in patients who are having implantation of a pacemaker or implantable cardioverter defibrillator (ICD) is a common clinical problem in which best clinical practise is not established.

METHODS

We performed a systematic review of the literature to assess the safety (pocket hematoma risk) and efficacy (thromboembolism risk) of different management strategies. We included studies involving patients who were having pacemaker or ICD implantation whenever a portion of these patients were receiving a coumarin and also assessed pocket hematoma or thromboembolism.

RESULTS

We identified eight studies that assessed two strategies used for perioperative anticoagulation management: interruption of a coumarin and use of bridging anticoagulation with a short-acting heparin; and perioperative continuation of a coumarin. A strategy involving bridging anticoagulation with therapeutic-dose heparin was associated with an incidence of pocket hematoma of 12-20%. A strategy involving perioperative continuation of a coumarin was associated with an incidence of pocket bleeding of 1.9-6.6%. The incidence of thromboembolic events was 0-1%, irrespective of the perioperative anticoagulation strategy used.

CONCLUSION

The perioperative anticoagulation management of patients who require pacemaker or ICD implantation is not established but a strategy involving postoperative bridging with intravenous heparin confers a high risk for bleeding whereas perioperative continuation of a coumarin appears to confer a lower risk for bleeding.