The Ultimate Test in Hemocompatibility: HeartMate 3 Restart After Prolonged Pump Shutdown

The HeartMate 3 (HM3) LVAD has been shown to have a higher survival free of hemocompatibility related adverse events (HRAE) compared to its predecessors (HMII, HVAD). Superior HM3 outcomes are attributed to wide blood flow pathways coupled with frictionless movement and intrinsic pulsatility, thereby reducing shear stress and blood stasis. At the other extreme, complete outflow graft thrombosis has been reported to occur shortly after pump decommissioning. In the case of prolonged pump stoppage, the manufacturer recommends against restarting the pump due to the risk of thromboembolism.

With this background in mind, at #AHA24 we reported a case of complete HM3 stoppage resulting in zero flow through the pump for several hours without subsequent HRAE. A 41-year-old male with a history of HVAD to HM3 exchange due to recurrent neurologic events awakened one morning to find his LVAD without power. Without seeking medical consultation, he took it upon himself to reestablish power to his device. It was later determined his pump was off for approximately eight hours prior to restart. Despite a subtherapeutic INR of 1.5 at the time, he had sustained no clinical or radiographic evidence of HRAE (no stroke, no outflow graft thrombosis, no elevation in hemolysis markers).

Our case adds to the paucity of existing data on improved hemocompatibility of the HM3 during rare circumstances of the ultimate test in hemocompatibility: complete pump shutdown.