Evaluation of bivalirudin titration protocol in patients with mechanical circulatory support

Background: Patients with cardiogenic shock or end-stage heart failure can be maintained on mechanical circulatory support (MCS) devices. Once a patient undergoes placement of a device, obtaining and maintaining therapeutic anticoagulation is vital. Guidelines recommend the use of institutional protocols to assist in dosing and titration of anticoagulants.Objective: 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.Methods: A retrospective review of patients who received bivalirudin for MCS (VA ECMO [veno-arterial extracorporeal membrane oxygenation], Impella, or LVAD [left ventricular assist device]) before and after the implementation of the titration protocol into the electronic health record (EHR) was conducted. The primary outcome was to compare the proportion of therapeutic activated partial thromboplastin time (aPTT). Secondary outcomes included number of subtherapeutic and supratherapeutic aPTTs, incidence of bleeding and clotting events, bivalirudin titrations per day, and percentage of patients with therapeutic aPTT level.Results: A total of 100 patients were included (precohort = 67; postcohort = 33). The proportion of therapeutic aPTTs was significantly higher in the postcohort than that in the precohort (62% vs 48%; P < 0.001). The postcohort had 0% of patients failing to achieve therapeutic aPTT levels. The number of titrations per day was significantly lower in the postcohort, with 1.20 titrations per day versus 1.93 in the precohort (P < 0.001).Conclusions: Implementation of the bivalirudin titration nomograms within the EHR significantly increased the number of therapeutic aPTTs, reduced the number of patients who never achieved a therapeutic aPTT, and reduced the required number of titrations per day.