(165) Evaluation of Bivalirudin Titration Protocol in Patients With Mechanical Circulatory Support

Introduction: Once a patient undergoes placement of a mechanical circulatory support (MCS) device, obtaining and maintaining therapeutic levels of anticoagulation is vital. Guidelines recommend the development and use of institutional protocols to assist in dosing and titration of anticoagulants in this patient population. The purpose of this study was to characterize the use of bivalirudin before and after the implementation of a standardized titration protocol in patients with MCS in a quaternary care hospital.

Methods: A retrospective review of patients who received bivalirudin for MCS (Venoarterial extracorporeal membrane oxygenation (VA ECMO), Impella®, or left ventricular assist device (LVAD)) before and after the institution of the standardized bivalirudin titration nomograms was conducted. The primary outcome was to compare the percentage of therapeutic aPTTs. Additional outcomes included number of sub- and supratherapeutic aPTTs, incidence of bleeding and clotting events, bivalirudin titrations per day, and percentage of patients who achieved therapeutic aPTT level during therapy.

Results: A total of 100 patients were included (pre-cohort=67; post-cohort=33). The percentage of therapeutic aPTTs was significantly higher in the post-cohort compared with the pre-cohort (62% vs 48%; p< 0.001). The post-cohort also had 0% of patients fail to achieve therapeutic aPTT levels compared to 17% in pre-cohort (p=0.014). Additionally, the number of titrations per day was significantly lower in the post-cohort with 1.20 titrations per day compared to 1.93 in the pre-cohort (p < 0.001). Bleeding and clotting events were infrequent and similar between groups.

Conclusions: Implementation of the bivalirudin titration nomograms within the electronic health record (EHR) significantly increased the number of therapeutic aPTTs, reduced the number of patients who never achieved at least one therapeutic aPTT on bivalirudin, and reduced the number of titrations required per day.