Drug That Targets Cardiac Muscle Cuts Risk of Heart Failure Hospital Visits

A new heart failure drug, which targets proteins that power the pumping function, helped patients avoid the emergency room and hospital stays, according to a study released today.

The GALACTIC-HF trial for Amgen’s omecamtiv mecarbil, presented during the virtual meeting of the American Heart Association Scientific Sessions, studied more than 8,000 patients with chronic heart failure in 35 countries. These patients were either already hospitalized or had been to the hospital or emergency room within the past year. The study excluded patients with recent heart attacks or strokes.

Results were also published in the New England Journal of Medicine.

Heart failure, which occurs when the heart cannot adequately pump blood through the body, is one of the most debilitating and expensive conditions in the health system; according to CDC, it is a contributing factor in 13% of all deaths and costs $30.7 billion a year, with Medicare footing most of the bill. As the population ages, the number of people with heart failure is expected to rise.

Most patients with heart failure have other comorbidities and their care is complex; indeed, 40% of the patients in GALACTIC also had diabetes. Typically, study patients were taking one or more of the current cocktail designed to slow heart failure’s progression: More than 85% were taking ACE inhibitors or ARBs or beta blockers, and 75% were taking a mineralocorticoid receptor antagonist (MRA). Smaller numbers were taking other medications, such as SGLT2 inhibitors.

For decades, clinicians have sought a different approach to treatment. But as the study authors note, earlier efforts to boost cardiac performance with therapy have backfired, causing side effects such as arrhythmias, or even death. Omecamtiv mercarbil is among a new wave of drugs being studied that addresses cardiac damage without causing adverse events. Another is vericiguat, by Bayer and Merck, which has different mechanism of action.

Heart failure has received more attention over the past decade, as the quality measurement movement has called on hospitals to keep heart failure patients from being readmitted. And omecamtiv mercarbil could be useful for hospitals, because it’s designed for patients to start taking it when they’re admitted for a heart failure episode.

Omecamtiv mercarbil targets cardiac myosin, a protein that creates the fuel that powers muscle contraction; it has been found to improve the heart’s function by promoting better interaction between proteins that power the heart muscle. After years of study, the FDA gave the study fast track designation in May 2020.

Results from GALACTIC-HF. Patients in the study were mostly male (79%) and White (78%), with an average age of 66 years and an average ejection fraction of 27%. Investigators noted the low enrollment of Black patients (7%) as an ongoing problem in heart failure trials, even though this percentage was better than many other trials.

The overall reduction in risk of the primary outcome, a composite of hospitalization, emergency room visit and death measures, was a significant was but modest 8%. This was driven by the reductions in hospitalization in and emergency room care, and investigators also found a greater effect among patients with an ejection fraction of 28% or less—suggesting the drug offers more help for those with more advanced heart failure.

Last spring, the VICTORIA trial for vericiguat also found that the drug performed differently among patients based on a biomarker that indicated their heart failure level. Vericiguat is an oral agent that activates soluble guanylyl cyclase, boosting production of a nucleotide with a “messenger” function that decreases fibrosis of the heart.

Commentators who spoke ahead of the release of the results said it remains to be seen where omecamtiv mercarbil and vericiguat will fit into the treatment picture, and which patients will take these medications.

Paul Heidenreich, MD, MS, professor of cardiovascular medicine at Stanford University, said the fact that omecamtiv mercarbil doesn’t reduce blood pressure is a plus.

“Often this is a major limiting factor for many patients,” he said. For heart failure patients who cannot tolerate other therapies, “This might be an option.”