Comparison of Hemocompatibility-Related Adverse Events between HeartMate 3 and HeartMate II Patients: A Propensity Score Matched Study

Objectives: The new left ventricular assist device (LVAD) HeartMate 3 (HM3) is a fully magnetically levitated pump, designed to avert hemocompatibility-related adverse events (HRAEs). We aimed to compare platelet function, von Willebrand factor (vWF) profile and HRAEs between HM3 and HeartMate II (HMII) patients.

Methods: From January 2016 to December 2016, twenty-five patients received HM3. Propensity matching was performed to match the HM3 patients to 25 HMII patients from our historical HMII cohort. Beside routine laboratory tests, PFA-100, vWF collagen binding activity (vWF:CBA), vWF antigen (vWF:Ag), vWF ristocetin cofactor activity (vWF:RCo) and vWF high-molecular-weight multimer (HMWM) analysis with western blot were performed 1-month postimplantation. Beside early AE, late HRAE >30 POD: gastrointestinal bleeding (GIB), ischemic stroke (IS), hemorrhagic stroke (HS) and pump thrombosis (PT) were evaluated and compared between HM3 and matched HMII patients for the first 9 postoperative months.

Results: Median follow-up of HM3 patients was 313 days. In 56% of HM3 patients, vWF HMWM were preserved compared to only 4% of HMII patients (p = 0.034). However, the mean of vWF:CBA/vWF:Ag and vWF:RCo/vWF:Ag ratios did not differ significantly between groups (HM3 vs. HMII: 0.82 ± 0.26 vs. 0.73 ± 0.19 and 0.71 ± 0.18 vs. 0.61 ± 0.19, p = ns, respectively). PFA-100 revealed prolonged closure time in both groups, but the values were significantly lower in the HM3 patients indicating lower grade of platelet type von Willebrand disease (vWD; collagen/epinephrine: 269 ± 51 vs. 297 ± 17, p = 0.016 and collagen/ADP: 193 ± 64 vs. 256 ± 57, p = 0.001). Two HM3 patients had HS within 30 POD compared to 1 HMII patient (p = 0.001) (0.09 vs. 0.01 eppy). One HMII and none of the HM3 patients had late HS (p = 0.010) (0.01 vs. 0 eppy). Two HM3 patients had 3 GIB events and 4 HMII patients had 18 GIB events (0.14 vs. 0.3 eppy, p = 0.072). One HMII patient and none of the HM3 patients had PT within 9 months (p = 0.010). None of HM3 patients had IS compared to 3 HMII patients (p = 0.001).

Conclusions: No thromboembolic events were noted in HM3 patients. The HM3 shows lower incidence of platelet type vWD. However, despite preservation of vWF HMWM the vWF:CBA/Ag and vWF:RCo/Ag ratios did not differ significantly compared to HMII patients and bleeding events remain a serious postoperative complication

No conflict of interest has been declared by the author(s).