HeartMate 3 Surgical Implant Technique and Outcomes in the MOMENTUM 3 Trial

Abstract

Purpose The HeartMate 3 (HM3) Left Ventricular Assist System is a fully magnetically levitated, centrifugal, continuous-flow pump. In the MOMENTUM 3 trial, the HM3 apical cuff could be attached with two different Methods Cut then Sew or Sew then Cut. This analysis describes the surgical techniques used in the trial and evaluates their impact on outcomes. Methods 189 patients in the Long Term (LT) cohort were implanted with the HM3 pump. Patients were divided into groups based on the technique used to attach the apical cuff at implant. Survival and adverse events at 2 years of follow-up were compared between the groups. The burden of hemocompatibility related adverse events (HRAE) was evaluated with a previously defined hemocompatibility score (Mehra. Eur Heart J. 2017). Continuous and categorical data were compared with the Wilcoxon rank sum and chi-square tests. The log-rank test was used to compare survival. This analysis will be updated to the 515 patients implanted with HM3 in the Full Cohort, which will be available in March 2019. Results 189 patients were implanted with HM3 by 68 surgeons at 52 centers. The median implant and bypass times were 261 and 83 minutes respectively. The majority of implants used the Cut then Sew apical attachment method (64%), true apical inflow cannula insertion (79%), silicone to skin driveline interface (90%), and right-sided driveline exit (54%). Cut then Sew was associated with longer median bypass times when compared to Sew then Cut (86 vs 77.5 minutes, p = 0.033). In the LT Cohort, there were no significant differences in 2-year survival between the groups (log-rank P=0.16). However, there was a trend for Cut then Sew to have a higher risk of stroke compared to Sew then Cut (Figure). Patients implanted with Cut then Sew vs Sew then Cut were also more likely to have a hemocompatibility score>1 (27% vs 15%, p=0.048). Conclusion We demonstrate that the Cut then Sew method used additional bypass time and may confer a higher stroke risk and HRAE net burden compared to Sew then Cut pump implantation technique.