LVAD Therapy: One Indication to Unite Them All?

Left ventricular assist device (LVAD) therapy has gotten good enough that distinguishing bridge-to-transplant from destination therapy is useless, researchers concluded from analysis of MOMENTUM 3.

In the main trial results, the HeartMate 3 (magnetically levitated, centrifugal flow) was better than HeartMate II (axial flow) heart pumps for patients with advanced heart failure in terms of 2-year survival free of disabling stroke or reoperation due to a malfunctioning device.

Now a prespecified secondary analysis showed the newer device was superior whether patients had initially been deemed at least possibly eligible for transplant (bridge-to-transplant group; HR 0.62 95% CI 0.40-0.94) or not (destination therapy group; HR 0.61, 95% CI 0.46-0.81), according to Mandeep Mehra, MD, MSc, of Brigham and Women’s Hospital in Boston, and colleagues reporting online in JAMA Cardiology.

“An equally important observation from this analysis pertains to the fact that the initial intended goal of therapy is not static … since nearly 15% of those initially deemed transplant ineligible were eventually transplanted within 2 years of follow-up,” according to the investigators.

“It is possible that use of arbitrary categorizations based on current or future transplant eligibility should be clinically abandoned in favor of a single preimplant strategy: to extend the survival and improve the quality of life of patients with medically refractory heart failure,” they suggested.

“I do agree with the authors’ suggestion that the designations may have less and less meaning in the future, particularly as we move towards safer devices,” said A. Reshad Garan, MD, of Beth Israel Deaconess Medical Center and Harvard Medical School.

“The concern historically has been that DT [destination therapy] patients would be at higher risk of adverse events with device support for a variety of reasons, including an anticipated longer period of time on the device. But as we move towards safer pumps, these concerns will likely abate,” Garan told MedPage Today.

While the bridge-to-transplant and destination therapy designations have been in use for more than 2 decades, they might be “no longer clinically distinctive in the current era of durable mechanical circulatory support,” Allen Anderson, MD, of the University of Texas, San Antonio, also agreed in an accompanying editorial.

“For the future, a patient’s need for LVAD and reimbursement for this procedure, as well as the approval of new MCS [mechanical circulatory support] systems, should be decided based on treatment of refractory stage D heart failure, with the goal of prolonging life while improving functional capacity and quality of life of patients with this debilitating condition,” the editorialist urged.

MOMENTUM 3 randomized patients with advanced heart failure roughly 1:1 to HeartMate 3 and HeartMate II LVADs. The secondary analysis relied on the per-protocol population of patients who actually received their assigned MCS devices (n=1,020).

Overall, 38.8% of trial participants got their devices as a bridge to transplant, the rest destination therapy, Mehra’s group found. Transplant-ineligible patients were older and more likely to have an ischemic cause of heart failure, prior coronary artery bypass grafting surgery, a history of atrial fibrillation, and worse renal function.

Among those assigned the HeartMate II, survival was higher with a bridging strategy than destination therapy. This trended similarly for the HeartMate 3 arm without reaching statistical significance.

Rates of adverse events did not differ by implant strategy: HeartMate 3 continued to be favored in rates of pump thrombosis, stroke, and GI bleeding between bridging and destination therapy groups.

Quality of life and functional capacity improvements remained similar between pumps, regardless of intended use, the authors also reported.

Mehra’s team acknowledged that the main trial was not blinded, nor was it powered for this secondary analysis comparing bridge-to-therapy and destination therapy groups.

“Taken in aggregate, these findings should open the door to greater confidence in consideration of LVAD therapy in patients deemed to be transplant ineligible,” they nevertheless concluded.

“The factors that make a patient DT versus BTT [bridge-to-transplant] encompass a heterogeneous group of clinical parameters, which makes the groups themselves somewhat heterogeneous,” Garan noted. “There is nothing inherent to the designation DT or BTT that should affect the way the patient derives a benefit from the pump.”

Getting rid of the distinction may be relevant for LVAD trials of the future, Anderson suggested. “Further pump development will depend in part on rational, efficient, and economical clinical trial design,” according to him.