Abstract

NM-235

The use of Kcentra as a warfarin reversal agent in pediatric patients undergoing orthotopic heart transplant.

Sisti D, Navaratnam M, Williams G, Chen S, Maeda K
Stanford School of Medicine, Palo Alto, CA, USA

Introduction

Patients supported with a ventricular assist device (VAD) are predisposed to severe bleeding at the time of orthotopic heart transplant (OHT) due to chronic anticoagulation with vitamin K antagonists (VKA). Kcentra is a 4-factor prothrombin complex concentrate which replaces vitamin K dependent clotting factors. In 2013 Kcentra was FDA approved to reverse VKA prior to urgent surgery (1). Despite emerging data from the adult cardiac population (2), there is no published data on the preoperative use of Kcentra in pediatric patients undergoing cardiac surgery.

Methods

This is a single center, retrospective, historical matched cohort study of pediatric patients with a HeartWare HVAD device who underwent OHT, comparing patients who received Kcentra with those who did not. Data include patient demographics and preoperative characteristics, dose and timing of Kcentra, intraoperative hemostasis management and markers of postoperative hemostasis. The primary outcome is volume of perioperative blood product transfusion and postoperative chest tube output. Secondary outcomes include postoperative thromboembolism and duration of intubation, ICU and hospital stay.

Results

From 2014 to 2017, 25 patients with HeartWare HVAD devices underwent OHT. 23 patients were anticoagulated with aspirin and warfarin, while 2 patients were on heparin only and were excluded from this study. 13 of 23 patients received preoperative vitamin K and Kcentra 25u/kg prior to incision and after direct visualization of the donor heart. The other 10 patients received vitamin K only. Compared with the control group, patients who received Kcentra had less total blood products (p=0.016) and red blood cell transfusion prior to the institution of cardiopulmonary bypass (p=0.009), and received less fresh frozen plasma in the first 24-hour postoperative period in the ICU (p=0.031). Patients who received Kcentra had reduced time to extubation (p=0.041), but no difference in chest tube output or ICU and hospital length of stay. Neither group had thromboembolic complications over 7 days.

Conclusion

This retrospective study indicates that preoperative warfarin reversal with Kcentra may reduce blood product exposure in pediatric patients with VADs undergoing OHT. We found no adverse effects of using Kcentra. Further large scale prospective studies are required to determine the true benefit and risk profile of preoperative VKA reversal with Kcentra in the pediatric cardiac population.

References
1. Gordon, J.L., Fabian, T.C., Lee, M.D. and Dugdale, M., 2013. Anticoagulant and antiplatelet medications encountered in emergency surgery patients: a review of reversal strategies. Journal of Trauma and Acute Care Surgery, 75(3), pp.475-486.
2. Smith, M.M., Ashikhmina, E., Brinkman, N.J. and Barbara, D.W., 2017. The Perioperative Use of Coagulation Factor Concentrates in Patients Undergoing Cardiac Surgery. Journal of Cardiothoracic and Vascular Anesthesia.