Discontinuation of Aspirin in HeartMate 3: Long-Term Outcomes

Favorable Hemocompatibility in HeartMate 3 May Prevent Thrombosis After Prolonged Pump Cessation

The HeartMate 3 Left Ventricular Assist System has demonstrated a reduction in risk of pump thrombosis. The improved hemocompatibility of this device is largely attributed to the pump mechanics including a large-diameter outflow graft, increased retrograde flow through the pump during pump cessation, and the textured blood-contacting surfaces of the pump. We present a 55-year-old man with a HeartMate 3 device who presented with heart failure symptoms, prolonged pump cessation for 7 days, and subtherapeutic anticoagulation therapy. Despite prolonged pump cessation and interrupted anticoagulation therapy, there was no evidence of pump thrombosis as determined by both laboratory and imaging studies. This case suggests favorable hemocompatibility of the HeartMate 3 device, which clinicians may consider in the management of patients needing advanced therapies.

Bleeding in patients with continuous-flow left ventricular assist devices: acquired von Willebrand disease or antithrombotics?

OBJECTIVES

To evaluate the competing pro-haemorrhagic contribution of acquired von Willebrand (vW) disease and antithrombotic therapy in patients implanted with continuous-flow left ventricular assist devices (LVADs).

METHODS

We compared the extent of vW factor (vWf) degradation [vWf antigen (vWf:Ag)] and a decrease of functional activity of large vWf multimers [vWf collagen binding (vWf:CB)] in LVAD patients who did and did not suffer from bleeding. Data were measured pre-implant, at short-term (t1: <3 months) and long-term (t2: >12 months) follow-up. The occurrence of primary bleeding events, as well as bleeding recurrence, was correlated with patient-specific vWf profile and antithrombotic regimen. Indeed, patients were discharged on warfarin (international normalized ratio: 2-2.5) and aspirin, with the latter withhold after a first bleeding episode.

RESULTS

Fifty-three patients were enrolled. The median follow-up was 324 (226-468) days. We recorded 25 primary bleeding events (47% of patients). All primary events occurred in patients on warfarin and aspirin. Both vWf:Ag and vWf:CB decreased significantly post-implant (P = 0.0003 and P < 0.0001), and patients showing pathological vWf:CB/vWf:Ag ratio (<0.7) increased progressively over the time of support (pre-implant = 26%, t1 = 58%, t2 = 74%; P < 0.0001). Of note, activity of large vWf multimers of bleeders was significantly lower at t2 with respect to non-bleeders (vWf:CB: 61 (36-115) vs 100 (68-121), P = 0.04; vWf:CB/vWf:Ag ratio: 0.36 (0.26-0.61) vs 0.58 (0.33-0.96), P = 0.04). Despite these marked differences in the vWf profile, following aspirin discontinuation only 3 patients had bleeding recurrence.

CONCLUSIONS

Aspirin contributes significantly to haemorrhagic events in the background of acquired vW disease; its discontinuation significantly reduces bleeding recurrence.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT03255928; ClinicalTrials.gov Identifier: NCT03255928.