title: Efficacy and safety of early parenteral anticoagulation as a bridge to warfarin after mechanical valve replacement.
abstract: Limited evidence exists to guide the use of early parenteral anticoagulation following mechanical heart valve replacement (MVR). The purpose of this study was to compare the 30-day rates of thrombotic and bleeding complications for MVR patients receiving therapeutic versus prophylactic dose bridging regimens. In this retrospective cohort study we reviewed anticoagulation management and outcomes of all patients undergoing MVR at five Canadian hospitals between 2003 and 2010. The primary efficacy outcome was thromboembolism (stroke, transient ischaemic attack, systemic embolism or valve thrombosis) and the primary safety outcome was major bleeding at 30-days. Outcomes were compared using a logistic regression model adjusting for propensity score and in a 1:1 propensity matched sample. A total of 1777 patients underwent mechanical valve replacement, of whom 923 received therapeutic dose bridging anticoagulation and 764 received prophylactic dose bridging postoperatively. Sixteen patients (1.8 %) who received therapeutic dose bridging and fifteen patients (2.1 %) who received prophylactic dose bridging experienced the primary efficacy outcome (odds ratio [OR] 0.90; 95 % confidence interval [CI], 0.37 to 2.18, p=0.81). Forty-eight patients (5.4 %) in the therapeutic dosing group and 14 patients (1.9 %) in the prophylactic dosing group experienced the primary safety outcome of major bleeding (OR 3.23; 95 % CI, 1.58 to 6.62; p=0.001). The direction of the effects, their magnitude and significance were maintained in the propensity matched analysis. In conclusion, we found that early after mechanical valve replacement, therapeutic dose bridging was associated with a similar risk of thromboembolic complications, but a 2.5 to 3-fold increased risk of major bleeding compared with prophylactic dose bridging.
authors.forename: J G
authors.initials: JG
authors.lastname: Mathew
authors.forename: A C
authors.initials: AC
authors.lastname: Spyropoulos
authors.forename: A
authors.initials: A
authors.lastname: Yusuf
authors.forename: J
authors.initials: J
authors.lastname: Vincent
authors.forename: J
authors.initials: J
authors.lastname: Eikelboom
authors.forename: O
authors.initials: O
authors.lastname: Shestakovska
authors.forename: S
authors.initials: S
authors.lastname: Fremes
authors.forename: J
authors.initials: J
authors.lastname: Noora
authors.forename: L
authors.initials: L
authors.lastname: Guo
authors.forename: M
authors.initials: M
authors.lastname: Peterson
authors.forename: M
authors.initials: M
authors.lastname: Pai
authors.affiliation: Dr. Richard Whitlock, MD, PhD, David Braley Cardiac, Vascular & Stroke Research Institute, 237 Barton Street East, Room 1C1-114, Hamilton, Ontario, Canada, L8L 2X2, Tel.: +1 905 521 2100 × 40306, E-mail: richard.whitlock@phri.ca.
authors.forename: R
authors.initials: R
authors.lastname: Whitlock
mesh_terms: D061605:Administration, Intravenous; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D016009:Chi-Square Distribution; D004334:Drug Administration Schedule; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation; D006470:Hemorrhage / Q000139:chemically induced; D006493:Heparin / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D002546:Ischemic Attack, Transient / Q000209:etiology / Q000517:prevention & control; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D009864:Ontario; D057216:Propensity Score; D011474:Prosthesis Design; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000209:etiology / Q000517:prevention & control; D013923:Thromboembolism / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome; D014859:Warfarin / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D006493:Heparin
keywords: Cardiac surgery; anticoagulants; heparin; thromboembolism; valvular heart diseases