Perioperative bridging of chronic oral anticoagulation in patients undergoing pacemaker implantation--a study in 200 patients.

OBJECTIVE: To assess the risk of bleeding and thromboembolism (TE) of bridging therapy with low molecular weight heparin (LMWH) in patients undergoing pacemaker implantation.

BACKGROUND: Current guidelines on peri-procedural management of patients with chronic oral anticoagulation (OAC) give no explicit recommendations on how to treat patients undergoing pacemaker implantations. METHODS AND RESULTS Since 2000 all patients with chronic OAC undergoing pacemaker implantation were prospectively enrolled and treated following a pre- specified bridging regimen with enoxaparin using reduced LMWH doses in patients at non high TE risk and renal impairment. Patients were followed up for 30 days regarding bleeding complications, incidence of thromboembolism, length of therapy and adverse events following bridging therapy. 200 patients (age 78.4 ± 8.3 years; 60.5% male) were enrolled and treated with enoxaparin for a mean of 7.3 ± 4.2 days. 109 patients (54.4%) were assigned to high TE risk and 91 (45.6%) to non high TE risk. Renal insufficiency (CrCl of <50 ml/min) was present in 92 patients (46%). After risk stratification 72.5% of patients (n = 145) were treated with reduced LMWH doses. Outpatient treatment was feasible in 39 patients (19.5%). Nine bleeding complications were observed (4.5%; 95% confidence interval [CI] 2.1-8.4%), including one major bleed (0.5%; 95% CI 0.01%-2.75%) and eight minor bleeds (4%; 95% CI 1.74%-7.73%). No thromboembolic complications evolved due to bridging therapy (0%; 95% CI 0.0-1.49%). After multivariate regression analysis independent predictors for bleedings were the development of thrombozytopenia (hazard ratio [HR] 6.0, 95% CI 0.3-139.8; P = 0.002), the prevalence of congestive heart failure (HR 4.5, 95% CI 0.9-22.2; P = 0.01), high TE risk (HR 6.9, 95% CI 1.9-25.6; P = 0.03) and an increasing CHADS₂ score (HR 2.3, 95% CI 1.0-5.4; P = 0.05).

CONCLUSION: Oral anticoagulation can be safely interrupted before pacemaker implantation under overlapping therapy with enoxaparin. Reducing heparin doses in patients with low thromboembolic risk and renal insufficiency led to a low incidence of major bleeding without increasing thromboembolic events.