MOMENTUM 3: HeartMate 3 Improves Stroke-Free Survival at 2 Years

Marlene Busko

March 13, 2018

ORLANDO — Patients with advanced heart failure who were randomly assigned to the HeartMate 3 (Abbott) heart pump were more likely to survive 2 years free of a disabling stroke or the need to remove or replace the pump than those who received the older-generation HeartMate II pump, in a new study.

Joseph C Cleveland Jr, MD, University of Colorado Hospital, Denver, presented these 2-year findings from the Multi-center Study of Maglev Technology in Patients Undergoing MCS Therapy with HeartMate 3 (MOMENTUM 3) trial of these two left ventricular assist devices (LVADs), here at the American College of Cardiology (ACC) 2018 Annual Scientific Session.

The study, which compared the newer magnetically levitated centrifugal continuous-flow circulatory pump vs the older-generation mechanical-bearing axial continuous-flow pump, was simultaneously published online March 11 in the New England Journal of Medicine.

"The takeaway messages," Cleveland said, "are that pump thrombosis, which seemed to be a major problem with HeartMate II, seems to be averted with HeartMate 3, basically with the exception of two suspected cases of pump thrombosis, neither of which actually led to reoperation in the HeartMate 3 arm."

"With regards to stroke," he continued, "a 10% absolute stroke risk at 2 years is the lowest we've seen with any durable LVAD."

"You've done a number of important things," said panel member Joseph G Rogers, MD, from Duke University, Durham, North Carolina, after the study's presentation. "You've changed the clinical trial paradigm in moving away from bridge-to-transplant in trials to something that's much more aligned with contemporary clinical practice."

Second, Rogers said, "I think you've identified that this patient population is energized and interested in enrolling in clinical trials."

These 2-year data will be part of an application to the US Food and Drug Administration (FDA) for use of this device for long-term destination therapy for patients with advanced heart failure.

"We finally found a very forgiving pump, but not a fully forgettable pump. The driveline still exits the patient; the batteries are still an issue, electrical problems are likely to continue to plague us," lead study author, Mandeep R Mehra, MD, from Brigham and Women's Hospital, Boston, Massachusetts, told | Medscape Cardiology at a press conference.

"But clearly, we've just made a sea change in the opportunity for patients with advanced heart failure," Mehra said.

"It's definitely practice changing," agreed James L Januzzi, MD, Harvard Medical School, Boston, the assigned discussant at the press conference, in an interview with | Medscape Cardiology.

"We see obvious evidence for improvement in efficacy, particularly in reducing the most dreaded complication of left ventricular assist devices, which is stroke," he noted.

There was also an unmistakably dramatic improvement in safety.

Clinicians may have hesitated to implant these devices because of concerns that their patients may be at high risk for both bleeding and thrombosis, "the double-edged sword that we deal with here."

Now this study, with a "dramatic reduction in pump thrombosis requiring reoperation — essentially 0% — really is a game changer in my view."

The MOMENTUM 3 trial randomly assigned patients to receive one of the two types of LVADs at 69 centers in the United States  in 2014 to 2015.  

Six-month data in 294 patients had shown that the newer device was superior in averting pump thrombosis. Shortly after, the FDA approved the device as a bridge to transplant.

The trial then enrolled an additional 72 patients to determine noninferiority at 2 years.  

Of the 366 with advanced heart failure, 190 received the HeartMate 3 and 176 received the HeartMate II.

The patients had a mean age of 60 years, and 80% were male. The device was intended as a bridge to transplant (25% of patients), a bridge to candidacy for transplant (16%), or destination therapy (59%).

The primary endpoint was survival at 2 years free of disabling stroke (a modified Rankin Scale score ≥ 3) or reoperation to replace or remove a malfunctioning device.

At 2 years, 151 patients (80%) in the HeartMate 3 pump group vs 106 patients (60%) in the HeartMate II pump group survived free of disabling stroke or need for reoperation (ie, they met the primary endpoint).

Most of the between-group difference in the primary endpoint was due to the lower rate of device replacement or removal with the newer-generation pump.

Table. Two-Year Outcomes With HeartMate 3 vs HeartMate II

Outcome Hazard Ratio (95% CI) P Value
Primary endpointa 0.46 (0.31 - 0.69) <.001
Disabling stroke 1.45 (0.56 - 3.75) .42
Death within 2 y 0.75 (0.43 - 1.33) .37
Reoperation 0.08 (0.03 - 0.27) <.001
aSurvival free of disabling stroke or need for reoperation.


Three patients (1.6%) in the HeartMate 3 group vs 30 patients (17%) in the HeartMate II group required a reoperation.

Two patients (1.1%) who received the HeartMate 3 pump vs 27 patients (26%) who received the HeartMate II pump had suspected pump thrombosis (P < .001).

The overall rate of disabling of nondisabling strokes was significantly lower in patients who received the HeartMate 3 vs HeartMate II (10% vs 19%, respectively; P = .02).

The rate of disabling stroke, however, was similar in both groups: 3 patients (11%) of those who received HeartMate 3 vs 2 patients (7%) who received HeartMate II.  

"It's pretty straightforward. We took one pump that is available today [HeartMate II], and we had a better-engineered pump [HeartMate 3] and we said, 'Let's see what happens at 2 years,'" Mehra summarized.

"Clearly the effect size is so large and it only gets larger over time. That's a practice-changing observation."

The trial was funded by Abbott. Cleveland has received research grants from HeartWare and St Jude Medical. Mehra has received consultant fees/honoraria from Abbott (previously St Jude Medical), Bayer Healthcare Pharmaceuticals, Johnson & Johnson (Janssen), Medtronic, Mesoblast, Nupulse CV, and Portola.

American College of Cardiology (ACC) 2018 Annual Scientific Session. Abstract 405-08.  Presented March 11, 2018.

N Engl J Med. Published online March 11, 2018. Abstract   

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