Mandeep Mehra

BWH investigators have found that heart failure patients who received a novel circulatory heart pump had lower rates of pump-related blood clots and stroke after two years compared to patients who had received a commercially available model. Mandeep R. Mehra, MD, executive director of the Center for Advanced Heart Disease and medical director of the Heart & Vascular Center, presented findings from the clinical trial known as MOMENTUM 3 at this year’s American College of Cardiology meeting in Orlando, Fla. Results were simultaneously published in The New England Journal of Medicine.

“This is a pivotal study in the field of advanced heart failure,” said Mehra. “Left ventricular assist devices have been in development for 40 years, and while there have been improvements in their technology, several challenges exist, including problems of blood clots forming in these devices, requiring device replacement. The field has been trying to engineer devices that could make these devices more compatible with blood, and we’re reporting on some important advances.”

The trial, sponsored by the HeartMate’s manufacturer, Abbott Inc., evaluated the performance of the HeartMate 3 left ventricular assist system versus its predecessor, the HeartMate II. The HeartMate 3, which includes several technological adaptations intended to reduce risk of complications, consists of a fully magnetically levitated, continuous centrifugal-flow circulatory pump. This means the device runs like a bullet train – its rotor contains no mechanical bearings, pushes blood using only magnetism and is thus frictionless. It is designed to reduce a form of mechanical strain on blood elements known as shear stress, which is thought to cause blood clots to form in pumps.

By comparison, the HeartMate II uses an axial-flow pump, which uses a rotor that spins on a central ruby bearing to pump blood from the heart throughout the body.

The trial evaluated how many participants had not suffered a disabling stroke or had an operation to replace or remove a malfunctioning device after two years. Researchers reported that about 78 percent of patients who received the HeartMate 3 did not experience a disabling stroke or need a reoperation compared to approximately 56 percent of those on the HeartMate II.

Only three people who received the newer pump needed a reoperation – and none of those due to blood clots – compared to 30 with the commercially available implant.

Improving Access to Novel Therapies

MOMENTUM 3 launched in 2014 and was designed to dramatically reduce the overall timeline for clinical trials. All patients with refractory heart failure who needed a cardiac pump were eligible for the trial, regardless of whether the pump was intended as bridge to transplantation or the primary therapy.

“Traditional trials must first complete safety testing, followed by testing in populations of healthier transplant eligible patients, and it can be more than a decade before the broader advanced heart failure population has access to such therapies,” said Mehra. “Removing restrictions based on transplant status resulted in a unique study that has been extremely successful in its enrollment and highly expeditious in delivering results.”

In its next phase, MOMENTUM 3 will evaluate 1,028 patients at the two-year mark to further validate the current findings. Results of the full cohort are expected in 2019.