Introduction: To estimate the three-month cumulative incidence of thromboembolism and bleeding among mechanical heart valve (MHV) patients receiving peri-procedural anticoagulation management, consecutive MHV patients referred to the Mayo Clinic Thrombophilia Center for peri-procedural anticoagulation management over the seven-year period, 1997-2003, were followed for three months for thromboembolism, bleeding and vital status.
Materials and methods: Warfarin was stopped 4-5 days prior to the procedure, and re-started after the procedure as soon as hemostasis was assured. The decision to provide bridging therapy with low molecular weight (LMWH) or unfractionated (UFH) heparin was individualized and based on the estimated risks of TE and bleeding.
Results: 556 MHV patients (372 aortic only, 136 mitral only, 48 with multiple valves) underwent 580 procedures. The three-month cumulative incidence of thromboembolism was 0.9% which included: cerebral ischemia (n=3), unstable angina (n=1), acute myocardial infarction (n=1). None were fatal. The cumulative incidence of major bleeding was 3.6% and fatal in 0.2%. The incidence of major bleeding events did not differ by postoperative anticoagulant strategy whether LMWH (3.7%), UFH (6.1%), or no heparin (2.4%) was used (p=0.26).
Conclusions: The three-month cumulative incidence of thromboembolism among MHV patients in whom anticoagulation is temporarily interrupted for an invasive procedure is low. Whereas bleeding exceeds thromboembolic complications, our current practice is to restart warfarin as soon as possible post-procedure. Post-procedural heparin use is reserved for patients with the highest thromboembolic risk (mitral MHV, multiple MHVs, MHV with prior stroke or atrial fibrillation) waiting at least 48 hours before initiating.