Background: Appropriate periprocedural management for chronically anticoagulated patients requires assessment of patient-specific thrombosis and bleeding risks. However, predictors of post-procedure bleeding are unknown.
Objectives: To determine the 3-month cumulative incidence and independent predictors of peri-procedural bleeding in chronically anticoagulated patients requiring temporary warfarin interruption for an invasive procedure.
Methods: In a protocol driven, cohort study design, all patients referred to the Mayo Clinic Thrombophilia Center for peri-procedural anticoagulation management (1997-2007; n = 2182), were followed forward in time to determine the 3-month cumulative incidence of peri-procedural bleeding (Kaplan-Meier product limit) and potential predictors of bleeding (Cox proportional hazards). Decisions to 'bridge' with low-molecular-weight heparin were based on estimated thromboembolism and bleeding risk.
Results: Indications for chronic anticoagulation included venous thromboembolism (38%), atrial fibrillation (30%) and mechanical heart valves (27%). Of these, 1496 (69%) patients received bridging therapy. The 3-month cumulative incidence rates of major and overall bleeding were 2.1% and 5.1%, respectively. Major bleeding occurred more frequently in patients receiving bridging therapy (3% vs. 1%; P = 0.017). Independent predictors (hazard ratio; 95% confidence interval) of major bleeding included mitral mechanical heart valve (2.2; 1.1-4.3), active cancer (1.8; 1.0-3.1), prior bleeding history (2.6; 1.5-4.5) and re-initiation of heparin therapy within 24 h after the procedure (1.9; 1.1-3.4).
Conclusion: Factors predisposing to peri-procedural bleeding are primarily patient-specific. Premature heparin re-initiation is an avoidable provider-specific variable to consider.
© 2011 International Society on Thrombosis and Haemostasis.