Advanced heart failure patients who received the HeartMate 3 left ventricular assist device (LVAD) in the MOMEMTUM 3 trial had fewer strokes and re-operations for pump malfunction compared with its predecessor, the HeartMate 2. The findings from Brigham and Women’s Hospital were published in the New England Journal of Medicine earlier this year and simultaneously presented at the 2018 American College of Cardiology Scientific Sessions.
Together, HeartMate 3 and MOMENTUM 3 represent both a major advance in mechanical circulatory support and an innovative trial design that helped it reach a broader patient population in a dramatically shorter timeframe than usual.
“Historically, mechanical heart pumps for heart failure were used for patients who were near death or dying, and would ultimately require heart transplantation,” explained Mandeep Mehra, MD, national co-principal investigator for the MOMENTUM 3 trial. “Today, we have a population of heart failure patients who are very sick, despite pharmacologic therapy, and they need durable circulatory support but not transplantation.” It is also important to evaluate innovative technologies in these patients in a timely manner.
MOMENTUM 3, the largest LVAD trial in the world, was open to patients with refractory heart failure who needed a cardiac pump, regardless of whether the pump was intended as a bridge to heart transplantation or a destination therapy. “By removing traditional restrictions based on transplant status, we achieved faster enrolment and highly expeditious delivery of study results that apply to a broad population of advanced heart failure patients,” said Dr. Mehra.
The HeartMate 3 is a potentially game-changing technology in mechanical circulatory support. Unlike the axial flow pump with mechanical bearings in its predecessors, the magnetically-levitated, continuous centrifugal-flow pump in HeartMate 3 is a major advance in preventing formation of blood clots within the pump. “The magnetically levitated rotor contains no mechanical bearings and moves the blood using only magnetism,” explained Dr. Mehra. “It is designed to reduce the shear stress that is thought to cause blood clots to form in mechanical circulatory pumps.”
The frictionless motor and wide blood flow paths of HeartMate 3 allows blood to traverse the device without being subjected to shear stress. “Its pulse algorithm increases and decreases speed every two seconds to better simulate natural physiologic pulsatile function and prevent stasis of blood in the device that could lead to clot formation,” said Dr. Mehra.
Indeed, two-year results in the first 366 MOMENTUM 3 patients showed significantly lower rates of pump-related blood clots and stroke compared with its predecessor. Two-year survival without a disabling stroke or reoperation for a malfunctioning pump was 79.5 percent for HeartMate 3 patients compared with 60.2% for HeartMate 2 patients. Fewer patients who received the HeartMate 3 needed a re-operation for pump malfunction (1.6 percent vs 17.0 percent) and no re-operations in the HeartMate 3 were due to blood clots. The final phase results, including two-year outcomes in 1,028 patients, are expected in 2019.
“In the past, we focused on adding years to people’s lives,” said Dr. Mehra. “Now, I think, with better engineered devices, we are able to focus on adding life to people’s years. With the reduced stroke and reoperation rates and improved survival in MOMENTUM 3, it is pretty clear that we are adding life to people’s years.”