Practice of bridging anticoagulation: guideline adherence and risk factors for bleeding.

ABSTRACT

BACKGROUND: Perioperative bridging with low-molecularweight heparins (LMWH) is applied to minimise the risk of thromboembolism (TE). Guidelines characterise patients at risk and strategies to be followed. We assessed guideline adherence in bridging episodes and identified possible risk factors for bleeding in a retrospective cohort study. METHODS: We searched the electronic patient data system of the Maastricht anticoagulation service, the Netherlands. We identified 181 patients on chronic anticoagulation who underwent surgery (222 procedures) and were bridged with LMWH. Guideline adherence was defined in terms of the relation between TE risk and the dose of LMWH administered, the bleeding risk of the procedure and the duration of postprocedural administration of LMWH. Logistic regression was used to identify risk factors for bleeding. RESULTS: Of all low TE risk patients (n=102), 84.3% were treated with therapeutic doses of LMWH. The median duration of postprocedural LMWH administration was eight days. The 30-day incidence of major bleeding in the entire group (n=222) was 11.3%. Two patients (0.90%) experienced a deep venous thrombosis. Creatinine clearance ≤40 ml/min (odds ratio (OR) 5.03, 95% confidence interval (CI) 1.25 to 20.26) and dental procedures (OR 3.32, 95% CI 1.22 to 9.04) were independent predictors for total bleeding. CONCLUSION: Guideline adherence was low, leading to prolonged bridging procedures, excess treatment of patients and high bleeding rates. The majority of patients had a low thromboembolic risk profile or underwent low-risk procedures. For patients with decreased creatinine clearance, reduced doses of LMWH should be considered to reduce bleeding risk.