Feasibility of Delayed Parenteral Heparin Initiation after HM3 Implantation

Abstract

The HeartMate 3 (HM3) LVAD has demonstrated the lowest rates of hemocompatibility adverse events (AEs) in randomized controlled trials. Despite this success, rate of bleeding remains high. HM3 instruction for use recommends starting parenteral heparin 12-24 hours after device implantation or when chest tube drainage is <50 ml/hr. In contrast, our program implemented a delayed IV heparin protocol (>2 days post implant). The aim of the study is to evaluate the association of thrombotic and hemorrhagic events with delayed heparin initiation in HM3 recipients METHODS: We performed a retrospective analysis of all HM3 patients implanted at a single center from Oct 1, 2015 to Jun 30, 2019. Patients who received IV heparin ≤2 days after implant were excluded from the analysis (n=6) RESULTS: 113 patients were included in the analysis. Mean follow up time was 382±331 days. Mean age was 57±12 years. The cohort was predominantly men (72%), African-American (77%) with a NICM etiology (74%). HM3 implantation as DT represented 54% of the population (BTT 26%). 18% of patients had a history of CVA pre-implant, 2% had history of GIB. The mean time to heparin initiation was 5±2 days. Mean time to warfarin and ASA initiation was 11±9 and 2+6 days respectively. The rates of neurologic event, and hemorrhagic/ischemic CVAs were numerically similar to the rates seen in clinical trials. No confirmed pump thrombosis event was seen. The rate of GI bleeding was higher than seen in trials. Overall, the survival of this cohort was 88% and 84% at 1 and 2 years, respectively CONCLUSION: In this single center study, a strategy of delayed heparin initiation post HM3 implantation does not appear to increase the risk of CVA or pump thrombosis. A prospective clinical study is warranted.