American Journal of Cardiovascular Drugs

, Volume 18, Issue 3, pp 223–229 | Cite as

Comparison of Warfarin Requirements in Post-cardiac Surgery Patients: Valve Replacement Versus Non-valve Replacement

  • Logan M. Olson
  • Andrea M. Nei
  • David L. Joyce
  • Narith N. Ou
  • Ross A. Dierkhising
  • Scott D. Nei
Original Research Article



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. 1.
    Duke Clinical Research Institute. STS General Thoracic Surgery Database Executive Summary: January 2002–December 2015 Procedures. Published Spring 2016. Accessed Aug 15, 2016.
  2. 2.
    Gillinov AM, Bagiella E, Moskowitz AJ, Raiten JM, Groh MA, Bowdish ME, et al. Rate control versus rhythm control for atrial fibrillation after cardiac surgery. N Engl J Med. 2016;374(20):1911–21.CrossRefPubMedPubMedCentralGoogle Scholar
  3. 3.
    Rahman M, BinEsmael TM, Payne N, Butchart EG. Increased sensitivity to warfarin after heart valve replacement. Ann Pharmacother. 2006;40(3):397–401.CrossRefPubMedGoogle Scholar
  4. 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
  5. 5.
    Butchart EG, Payne N, Li HH, Buchan K, Mandana K, Grunkemeier GL. Better anticoagulation control improves survival after valve replacement. J Thorac Cardiovasc Surg. 2002;123(4):715–23.CrossRefPubMedGoogle Scholar
  6. 6.
    Garcia D, Regan S, Crowther M, Hughes RA, Hylek EM. Warfarin maintenance dosing patterns in clinical practice: implications for safer anticoagulation in the elderly population. Chest. 2005;127(6):2049–56.CrossRefPubMedGoogle Scholar
  7. 7.
    Berg TM, O’Meara JG, Ou NN, Daniels PR, Moriarty JP, Bergstrahl EJ, et al. Risk factors for excessive anticoagulation among hospitalized adults receiving warfarin therapy using a pharmacist-managed dosing protocol. Pharmacotherapy. 2013;33(11):1165–74.CrossRefPubMedGoogle Scholar
  8. 8.
    del Campo M, Roberts G. Changes in warfarin sensitivity during decompensated heart failure and chronic obstructive pulmonary disease. Ann Pharmacother. 2015;49(9):962–8.CrossRefPubMedGoogle Scholar
  9. 9.
    Rose JP, Rihn TL, Long SF. Warfarin sensitivity after mechanical heart valve replacement. Pharmacotherapy. 1998;18(4):856–9.PubMedGoogle Scholar
  10. 10.
    Ageno W, Turpie AG. Exaggerated initial response to warfarin following heart valve replacement. Am J Cardiol. 1999;84(8):905–8.CrossRefPubMedGoogle Scholar
  11. 11.
    Meijer K, Kim YK, Schulman S. Decreasing warfarin sensitivity during the first three months after heart valve surgery: implications for dosing. Thromb Res. 2010;125(3):224–9.CrossRefPubMedGoogle Scholar
  12. 12.
    Ageno W, Turpie AG, Steidl L, Ambrosini F, Cattaneo R, Codari RL, et al. Comparison of a daily fixed 2.5-mg warfarin dose with a 5-mg, international normalized ratio adjusted, warfarin dose initially following heart valve replacement. Am J Cardiol. 2001;88(1):40–4.CrossRefPubMedGoogle Scholar
  13. 13.
    Maisel WH, Rawn JD, Stevenson WG. Atrial fibrillation after cardiac surgery. Ann Intern Med. 2001;135(12):1061–73.CrossRefPubMedGoogle Scholar
  14. 14.
    Chelazzi C, Villa G, De Gaudio AR. Postoperative atrial fibrillation. ISRN Cardiol. 2011;2011:203179.CrossRefPubMedPubMedCentralGoogle Scholar
  15. 15.
    Echahidi N, Pibarot P, O’Hara G, Mathieu P. Mechanisms, prevention, and treatment of atrial fibrillation after cardiac surgery. J Am Coll Cardiol. 2008;51(8):793–801.CrossRefPubMedGoogle Scholar
  16. 16.
    Jongnarangsin K, Oral H. Postoperative atrial fibrillation. Cardiol Clin. 2009;27(1):69–78 viii.CrossRefPubMedGoogle Scholar
  17. 17.
    Nair SG. Atrial fibrillation after cardiac surgery. Ann Cardiac Anaesth. 2010;13(3):196–205.CrossRefGoogle Scholar
  18. 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. 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. 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

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  • Logan M. Olson
    • 1
  • Andrea M. Nei
    • 2
  • David L. Joyce
    • 3
  • Narith N. Ou
    • 2
  • Ross A. Dierkhising
    • 4
  • Scott D. Nei
    • 2
  1. 1.Department of PharmacyThe Ohio State University Wexner Medical CenterColumbusUSA
  2. 2.Department of PharmacyMayo Clinic HospitalRochesterUSA
  3. 3.Division of Cardiovascular SurgeryMedical College of WisconsinMilwaukeeUSA
  4. 4.Division of Biomedical Statistics and InformaticsMayo Clinic HospitalRochesterUSA

Personalised recommendations