Evaluation of low-intensity anti-coagulation with a fully magnetically levitated centrifugal-flow circulatory pump-the MAGENTUM 1 study

Abstract

Background: The HeartMate 3 left ventricular assist system is engineered to avoid pump thrombosis, yet bleeding complications persist. We investigated the safety of low-intensity anti-coagulation in patients with the HeartMate 3.

Methods: The Minimal AnticoaGulation EvaluatioNTo aUgment heMocompatibility (MAGENTUM 1) pilot study is a prospective, single-arm study of low-intensity warfarin anti-coagulation in patients implanted with the HeartMate 3 pump. After standard warfarin anti-coagulation (international normalized ratio [INR] 2.0 to 3.0) and aspirin for 6 weeks post-implant, patients were transitioned to a lower INR target range of 1.5 to 1.9. The primary end-point was a composite of survival free of pump thrombosis, disabling stroke (modified Rankin score [MRS] >3), or major bleeding (excluding peri-operative bleeding) with at least 6-month post-implant follow-up. Time in therapeutic range (TTR) was measured to assess anti-coagulation target efficacy using the Rosendaal method. A safety algorithm to monitor for signs of pump thrombosis was developed and implemented.

Results: We enrolled 15 patients (mean age 57.3 ± 13.3 years), 13 men with advanced heart failure (67% with INTERMACS Profiles 2 or 3), irrespective of therapeutic goal of bridge-to-transplant or destination therapy. The primary end-point was met in 14 of 15 (93 ± 6%) patients; 1 patient developed recurrent gastrointestinal bleeding. The TTR during the reduced anti-coagulation phase (6 weeks to 6 months) was 75.3 ± 8.6%. No thrombotic events occurred.

Conclusions: This pilot study suggests low-intensity anti-coagulation targeting an INR between 1.5 and 1.9 is achievable and safe with the HeartMate 3 cardiac pump in the short-term phase, 6-months post-implant. A large-scale trial is now warranted.

Trial registration: ClinicalTrials.gov NCT03078374.

Keywords: HeartMate 3; INR management; LVAD; Rosendaal method; TTR; left ventricular assist device; reduced intensity anti-coagulation; time in therapeutic range.