Safety and Feasibility of Home INR Monitoring for Outpatient Ventricular Assist Device Support in Children.

PURPOSE: The use of intracorporeal continuous flow (CF) ventricular assist devices- namely the Heartware™ HVAD™- has expanded dramatically in the children, with many being discharged home. We sought to evaluate the feasibility and outcomes of children discharged home with point of care (POC) INR monitors for their warfarin anticoagulation management.

METHODS: This is a retrospective single center review of all pediatric patients, aged ≤19 years at time of implantation, who were discharged home for longer than 1 week. Efficacy of warfarin anticoagulation and outcomes were evaluated in those with home POC monitors as compared to children who went to laboratory.

RESULTS: Between November 11, 2012 and January 1, 2018, a total of 12 patients, 33% female, aged median 14.5 years (range 10-18 years), weighing median 65.8kg (range 18.0-89.5 kg) were discharged home or to rehab with HeartWare as a bridge to transplantation. Underlying diagnosis included dilated cardiomyopathy in 67% (n=8), arrhythmogenic right ventricular dysplasia (ARVD) in 8% (n=1), and biventricular congenital heart disease (CHD) in 25% (n=3).Two patients were discharged to rehab before returning home. All patients were discharged with Coagucheck XS™ POC INR machines, with goal INR of 2-3 in first 3 patients (23%) and goal INR of 2.5-3.5 in later 10 patients. There were a median number of INR tests of 27 (range 1-99) at home, over the course of a median 185 days (25-625) outpatient VAD support days. Overall median time in the therapeutic range(TTR) was 62.1%(range 20.0-70.7%). There was 100% adherence to clinician recommended INR testing at home. There was 4 bridging events with low molecular weight heparin for sub-therapeutic INR. There were no pump thrombosis or other thrombotic events. There were no major bleeding or clinically relevant non major bleeding events. Epistaxis was the most common minor bleeding event that was mitigated by dose reductions and preventative strategies. All patients were bridged to transplantation with no mortality.

CONCLUSION: Use if home POC INR machines in children with intracorporeal VADs, in the outpatient setting was associated with 100% adherence to recommended testing regime. Despite low TTR, there was no major bleeding or thrombotic events.