Heartmate 3 Review

By Pablo Motta, MD, FAAP
Baylor College of Medicine and Texas Children’s Hospital

The HeartMate 3 (HM3) (Abbott Cardiac Arrhythmias and Heart Failure, Plymouth, MN) is a new generation centrifugal ventricular assist device (VAD) characterized by a fully levitated rotor that lacks mechanical bearings. The HM3 design has short and wide inflow that decreases shear stress and provides a reliable blood flow pattern supply (Figure 1). The HM3 incorporates a “pulsatility” featurewherein the rotor drops below the set speed and immediately increases above the set speed generating a pulse (~30 cycles per minute). The purpose of “pulsatility” is to allow ejection through the aortic valve reducing stasis and thrombosis. The HM3 insertion is intrapericardial similarly to the HeartWare® HVAD. The modular driveline can be changed in the event of malfunction without needing complete pump exchange.

Fig 1

Figure 1

The control screen consists of four boxes displaying pump flow, pump speed, pulsatility index (abbreviated on screen as pulse index), and pump power (Figure 2). The HM3 allows wide range of working speeds accomplishing flows between 2.5 – 10.0 L/min. The pump flow is a calculated value. The pulsatility index value is inversely proportional to support given. The higher the pulsatility index the lesser the VAD support. The HM3 power ranges between 0.0 to 25.5 watts. Any change of set range values will trigger alarms as in any other VAD. Five life threatening alarms are displayed on the system monitor, which include pump off, driveline disconnection, low flow x min, low voltage and no external power. Low-level speed is considered fewer than 3000 rpm. The miniaturized pocket size controllers and 17 hours battery pack life supports an ambulatory lifestyle.

Fig 2

Figure 2

Intraoperative tranesophageal echocardiography imaging, is similar to other continuous flow VAD. The inflow cannula is easy to identify in mid-esophageal four-chamber view. It is a short cannula so kinking is unlikely (Figure 3A, Video Clip HM3A). The outflow cannula is better visualized in the mid esophageal aortic long axis view. Is not as echo bright as the inflow cannula so color flow Doppler helps to identify it (Figure 3B and 3C, Clip HM3B and HMCC).

Fig 3

Figure 3A

The FDA in 2018 approved the HM3 VAD for the management of patients with end-stage left-sided heart failure for bridge to transplant (BTT), myocardial recovery, or destination therapy (DT) and a body surface area (BSA) >1.5 m2.  The HM3 has been used off label in pediatric patient with smallest reported insertion in a 19 kg patient (BSA 0.78 m2).  

In 2017 the result of the Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HM3 (MOMENTUM 3 trial), compared HM3 with the HeartMate II as a bridge to BTT, bridge to transplant candidacy (BTC) or as DT were published. Outcome at six months was better with HM3 possibly due to lower rate of reoperation secondary to pump malfunction. The two-year follow of this trial showed that the survival free of disabling stroke and reoperation was improved with the HM3 in all the indication BTT/BTC or DT. There was no difference among the groups in thrombosis, stroke or gastrointestinal bleeding. Schramm et al reported in a retrospective study the short-term outcomes (median 15.3 months) of HeartWare® HVAD and HM3.

Both VADs had similar survival and freedom from cerebrovascular events. The HM3 patients developed driveline infections less frequently and presented no episodes of pump thrombosis. In patients who regain function after HM3 therapy, the explanation with the recovery plug have been described. The pediatric experience with HM3 is limited.

Recently, O’Connor et al published the first pediatric HM3 series (40% of the patients < 60kg) including a few with congenital heart disease (mostly Fontan circulation) who presented a low incidence of mortality and/or adverse events. Traditional anticoagulation regime for HM3 includes coumadin (INR target 2.0 – 3.0) plus anti-aggregation with aspirin (100-200 mg day). The MAGENTUM 1 trial showed that after six weeks stabilization low intensity anticoagulation with coumadin to a lower INR target (1.5-1.9) and aspirin was effective without an increase in the thromboembolic complications.

Keywords: Centrifugal pump; left ventricular assist device (LVAD); HeartMate 3

Reference:

  1. https://www.accessdata.fda.gov/cdrh_docs/pdf16/P160054C.pdf (Last accessed 04/30/2020).
  2. https://www.fda.gov/medical-devices/recently-approved-devices/heartmate-3-left-ventricular-assist-system-lvas-p160054s008 (Last accessed 04/30/2020).
  3. Slaughter MS, Rogers JG, Milano CA, et al. Advanced Heart Failure Treated with Continuous-Flow Left Ventricular Assist Device. N Engl J Med 2009; 361: 2241-51.
  4. Mehra MR, Naka Y, Uriel N, et al: A Fully Magnetically Levitated Circulatory Pump for Advanced Heart Failure N Engl J Med. 2017 Feb 2;376(5):440-450.
  5. Association of Clinical Outcomes With Left Ventricular Assist Device Use by Bridge to Transplant or Destination Therapy Intent: The Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3 (MOMENTUM 3) Randomized Clinical Trial. JAMA Cardiol. 2020 Jan 15. doi: 10.1001/jamacardio.2019.5323. [Epub ahead of print].
  6. Schramm R, Zittermann A, Morshuis M et al: Comparing Short-term Outcome After Implantation of the HeartWare® HVAD® and the Abbott® HeartMate 3®. ESC Heart Fail. 2020 Mar 19. doi: 10.1002/ehf2.12649. [Epub ahead of print].
  7. Mulzer J, Faerber G, Kaufmann F: Recovery Plug for HeartMate 3 Left Ventricular Assist Device. J Thorac Cardiovasc Surg. 2019 Feb;157(2):e35-e37.
  8. O'Connor MJ, Lorts A, Davies RR et al: Early Experience with the HeartMate 3 Continuous-Flow Ventricular Assist Device in Pediatric Patients and Patients with Congenital Heart disease: A Multicenter Registry Analysis. J Heart Lung Transplant. 2020 Feb 13. pii: S1053-2498(20)31393-0. doi: 10.1016/j.healun.2020.02.007. [Epub ahead of print].
  9. Netuka I, Ivak P, Tucanova Z et al: A Trial of Complete Withdrawal of Anticoagulation Therapy in the Heartmate 3 Pump. J Heart Lung Transplant 2018 May;37:579-586.

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