Peri-Operative Warfarin Protocol to Decrease Length of Stay After Left Ventricular Assist Device Implantation

Abstract

<h3>Purpose</h3> A limitation to left ventricular assist device (LVAD) implantation is cost with fixed reimbursement rates for the LVAD implantation hospitalization regardless of hospital length of stay and costs. Patients must have a therapeutic INR on warfarin prior to discharge which can take days and delay discharge. The purpose of this study is to evaluate the impact of a peri-operative warfarin protocol on decreasing length of stay during index LVAD implantation. <h3>Methods</h3> This is a retrospective single center study of adult patients undergoing LVAD implantation between January 1, 2019 and December 31, 2020. Patients who died during the admission were excluded. Patients in the intervention group (INT) underwent LVAD between January 1-December 31, 2020. The peri-operative warfarin protocol included pre-operative vitamin K dosing according to INR, initiation of warfarin by post-operative day (POD) 3, and warfarin titration scheme. The historical control group (CON) included patients receiving LVADs between January 1-December 31, 2019. Warfarin start date was at the discretion of providers. All patients had a goal INR of 2-3. Endpoints included length of stay, post-operative warfarin start date, time to therapeutic INR, warfarin dosing requirements, pre-operative vitamin K dosing and bleeding complications. <h3>Results</h3> Seventy-seven patients were included; n=41 (53.2%) CON and n=36 (46.8%) INT. Total hospital length of stay was 35 [26,43] days in the CON group compared to 27.5 [24,35] days in the INT group (p=0.095). Warfarin was started earlier in the INT group (POD 5.5 [2.8,7.0]) compared to the CON group (POD 8 [6,14]) (p=0.004). Time to therapeutic INR remained the same between the two groups with a median of 6 days. Pre-operative vitamin K decreased from 15 [10,15] mg in the CON group to 5 [0.0,11.3] mg in the INT group (p=<0.001). There was no increase in bleeding with the peri-operative warfarin interventions: 8 bleeds in the CON group and 4 bleeds in the INT group. <h3>Conclusion</h3> Initiating warfarin earlier post-operatively may help decrease hospital length of stay after LVAD implantation without increasing bleeding events.