Final MOMENTUM 3 Results Presented for Abbott's HeartMate 3 LVAD

March 17, 2019—Final results from the MOMENTUM 3 clinical trial evaluating the magnetically levitated HeartMate 3 left ventricular assist device (LVAD; Abbott Structural Heart) were presented by Mandeep R. Mehra, MD, at the American College of Cardiology's (ACC) 67th annual scientific session, being held March 16–18 in New Orleans, Louisiana. The study findings were simultaneously published online by Dr. Mehra et al in The New England Journal of Medicine.

ACC announced that the findings demonstrated that severely ill patients with advanced heart failure who received the HeartMate 3 LVAD experienced significantly fewer strokes, pump-related blood clots, and bleeding episodes after 2 years compared with similar patients who received an earlier-generation HeartMate II device. The MOMENTUM-3 study was funded by Abbott.

The HeartMate 3 received approval from the FDA in August 2017 for short-term use in patients awaiting a heart transplant. In October 2018, FDA approval for long-term use in patients who are not candidates for a heart transplant. The HeartMate 3 uses fully magnetic levitation technology, which makes the pump frictionless without mechanical bearings.

Dr. Mehra advised that based on these final findings, the HeartMate 3 LVAD should now be considered the standard of care for patients with advanced heart failure who do not respond to guideline-directed medical therapy.

In the ACC announcement, Dr. Mehra commented, “These final results from what is by far the largest LVAD trial ever conducted demonstrate the clinical superiority of the HeartMate 3 compared with its predecessor, the HeartMate II. We have shown a decrease in adverse events that uniquely occur due to the interface between the patient and the mechanical pump. These include a consistent and reliable reduction in strokes of all kinds and severity with the HeartMate 3 but also a remarkable reduction in the rate of pump-related blood clots and significant reductions in all types of bleeding, especially gastrointestinal bleeding. In addition to having significantly lower rates of adverse events, patients who received the HeartMate 3 had a lower rate of readmission to the hospital and spent fewer days in the hospital when they were readmitted.” Dr. Mehra is Medical Director of the Heart and Vascular Center, Brigham and Women’s Hospital in Boston, Massachusetts.

As summarized in the ACC press release, the MOMENTUM-3 trial enrolled 1,028 patients at 69 centers in the United States. Patients’ median age was 60 years and 78% were men. All had severe heart failure that left them unable to engage in usual physical activity without discomfort.

Most patients had symptoms of fatigue or shortness of breath, even when resting. Most patients (85%) were on intravenous heart failure medication because oral medical alone no longer worked or caused intolerable adverse effects.

Some patients in the study needed an LVAD to sustain them until they were able to receive a heart transplant. Others, because of age or other health problems, were not candidates for a transplant and relied on an LVAD as lifelong therapy.

Patients were randomly assigned to have either a HeartMate 3 or a HeartMate II surgically implanted. All patients received blood-thinning medications following surgery and were also taking 81 to 325 mg of aspirin daily.

The MOMENTUM 3 trial was designed to include two prespecified interim analyses and then a final analysis. The first interim analysis reported 6-month outcomes in the first 294 patients. The second analyzed 2-year outcomes for the first 366 patients enrolled. These data were presented at ACC’s 2018 Annual Scientific Session.

The primary endpoint for the final analysis was survival at 2 years that was free of disabling stroke or reoperation to replace or remove a malfunctioning device. The principal secondary endpoint was the rate of device replacement at 2 years.

At 2 years, HeartMate 3 met the primary endpoint, demonstrating a 40% reduction in risk compared with HeartMate II (74.7% vs 60.6%).

The investigators found the following events rates for HeartMate 3 versus HeartMate II:

• Pump replacement (2.3% vs 11.3%)
• Pump clotting (1.4% vs 13.9%)
• Disabling stroke (5% vs 7.5%)
• Any type of bleeding (43.7% vs 55%)
• Gastrointestinal bleeding (24.5% vs 30.9%)

Additionally, patients treated with the HeartMate 3 device spent more days on LVAD support outside of the hospital (a median of 48 more days in the HeartMate 3 arm) and spent fewer days in the hospital after being readmitted (a median of 13 days vs 18 days for HeartMate II patients).

Noting that patients continued to be at increased risk for infections at 2 years of follow-up, Dr. Mehra advised that he and his colleagues are engaging with infectious disease experts to try to find ways of reducing susceptibility to infection in patients with advanced heart failure.

The investigators plan to continue to follow the MOMENTUM 3 patients for at least another 3 years to monitor their long-term survival. Additionally, the investigators are developing a new trial that will examine how to optimize medical therapy for patients with advanced heart failure—for example, whether bleeding episodes might be further reduced by discontinuing daily aspirin or switching from the traditional blood thinner, warfarin, to newer blood-thinning medications.