Comparison of Warfarin Requirements in Post-cardiac Surgery Patients: Valve Replacement Versus Non-valve Replacement
- 84 Downloads
Anticoagulation with warfarin affects approximately 140,000 post-cardiac surgery patients every year, yet there remains limited published data in this patient population. Dosing remains highly variable due to intrinsic risk factors that plague cardiac surgery candidates and a lack of diverse literature that can be applied to those who have undergone a cardiac surgery alternative to heart valve replacement (HVR). In the present study, our aim was to compare the warfarin requirements between HVR and non-HVR patients.
This was a single-center, retrospective study of post-cardiac surgery patients initiated on warfarin at Mayo Clinic Hospital, Rochester, from January 1st, 2013 to October 31st, 2016. The primary outcome was the maintenance warfarin dose at the earliest of discharge or warfarin day 10 between patients with HVR and non-HVR cardiac surgeries.
A total of 683 patients were assessed during the study period: 408 in the HVR group and 275 in the non-HVR group. The mean warfarin maintenance doses in the HVR and non-HVR groups were 2.55 mg [standard deviation (SD) 1.52] and 2.43 mg (SD 1.21), respectively (adjusted p = 0.65). A multivariable analysis was performed to adjust for gender, age, body mass index and drug interactions.
This was the largest study to evaluate warfarin dose requirements in post-cardiac surgery patients and is the first to compare warfarin requirements between HVR and non-HVR patients during the immediate post-operative period. Both groups had similar warfarin requirements, which supports expanding the initial warfarin dosing recommendations of the 9th edition Chest guideline to include non-HVR patients as well as HVR patients.
Jason Weis, Department of Cardiovascular Surgery, Mayo Clinic Hospital. Contribution: Invaluable assistance performing data collection and consulting on database management.
Funding was provided by the Mayo Clinic Hospital Department of Pharmacy.
Compliance with ethical standards
Conflict of interest
Logan M. Olson, Andrea M. Nei, David L. Joyce, Narith N. Ou, Ross A. Dierkhising and Scott D. Nei declare that they have no conflicts of interest that might be relevant to the contents of this manuscript.
- 1.Duke Clinical Research Institute. STS General Thoracic Surgery Database Executive Summary: January 2002–December 2015 Procedures. http://www.sts.org/national-database/database-managers/executive-summaries. Published Spring 2016. Accessed Aug 15, 2016.
- 4.January CT, Wann LS, Alpert JS, Calkins H, Cigarroa JE, Cleveland JC Jr, et al. AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines and the Heart Rhythm Society. Circulation. 2014;130(23):e199–267.CrossRefPubMedPubMedCentralGoogle Scholar
- 18.Whitlock RP, Sun JC, Fremes SE, Rubens FD, American College of Chest P. Teoh KH Antithrombotic and thrombolytic therapy for valvular disease: antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2 Suppl):e576S–600S.CrossRefPubMedPubMedCentralGoogle Scholar
- 19.Ageno W, Gallus AS, Wittkowsky A, Crowther M, Hylek EM, Palareti G. Oral anticoagulant therapy: antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2 Suppl):e44S–88S.CrossRefPubMedPubMedCentralGoogle Scholar
- 20.Holbrook A, Schulman S, Witt DM, Vandvik PO, Fish J, Kovacs MJ, et al. Evidence-based management of anticoagulant therapy: antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2 Suppl):e152S–84S.CrossRefPubMedPubMedCentralGoogle Scholar