Heart failure

Stem cell therapy for heart failure reduced major heart events and mortality


November 19, 2021 – Stem cell therapy helped reduce heart attacks, strokes and deaths in people with high-risk NYHA class II or III chronic heart failure with fraction d reduced ejection (HFrEF), especially in those with reduced ejection fraction (HFrEF) inflammation levels, but hospitalization has not been reduced, according to late-breaking research presented at the 2021 Science Sessions of the American Heart Association.

Heart failure is a condition when the heart is unable to adequately pump blood to meet the body’s needs for oxygen and nutrients. In heart failure with reduced ejection fraction (HFrEF), the heart muscle enlarges and weakens, resulting in decreased pumping capacity and fluid buildup in body tissues. Inflammation plays an important role in the progression of heart failure over time.

This study aimed to examine the effects of using stem cells (mesenchymal precursor cells) injected into the heart to target inflammation and treat chronic heart failure. The researchers hypothesized that a single injection of stem cells from healthy adult donors in addition to guideline-directed medical treatment (GDMT) for heart failure would affect the number of participants’ hospitalizations for heart failure events and would reduce heart attacks, strokes and / or death.

“Cell therapy has the potential to change the way we treat heart failure,” said Emerson C. Perin, MD, Ph.D., lead author of the study, director of the Center for Clinical Research and medical director of the Texas Heart Institute in Houston. “This study focuses on the inflammatory aspects of heart failure, which for the most part go untreated, despite the significant development of pharmaceutical therapy and devices. Our results indicate that stem cell therapy can be considered for use in addition to standard therapies.

The study “Randomized trial of targeted transendocardial delivery of mesenchymal precursor cells in patients with high-risk chronic heart failure with reduced ejection fraction”, also called the DREAM-HF trial, is the largest therapy study by stem cells to date in people with heart failure. In this multicenter, randomized, sham-controlled, double-blind trial, researchers recruited 537 participants (mean age 63, 20% female) with heart failure and a reduced ejection fraction, i.e. that is, when the left side of the heart, its main pumping chamber, is considerably weakened.

Heart failure was defined using the New York Heart Association (NYHA) Functional Classification System. This classification system places patients in one of four categories based on their degree of limitation during physical activity. Class I heart failure means no limitation in physical activity, class IV heart failure means an inability to perform physical activity without discomfort.

The participants were randomly divided into two groups: 261 adults were injected with 150 million mesenchymal precursor cells, commonly known as stem cells, directly into the heart through a catheter. The remaining 276 adults received a scripted or fictitious procedure. Healthy adult donors provided the mesenchymal precursor cells.

Study participants were discharged from hospital the day after surgery, and researchers followed these participants for an average of 30 months. The aim of the study was to examine whether stem cell therapy affected the likelihood of participants returning to hospital for treatment of worsening heart failure. They also tracked whether participants had a heart attack or stroke, or died, and measured levels of high-sensitivity C-reactive protein (CRP), a measurement in the blood indicating inflammation.

Although the researchers did not see a decrease in hospitalizations due to the stem cell treatment, they did notice several other significant results. The results include:

  • Those who received stem cell therapy had a 65% reduction in non-fatal heart attacks and strokes throughout the study period;
  • Participants with high levels of inflammation (CRP levels of at least 2 mg / L) were 79% less likely to have a heart attack or non-fatal stroke after being treated with stem cells; and,
  • Stem cell therapy reduced heart mortality by 80% in people with high levels of inflammation and less severe class II heart failure.

“We were impressed to learn that the effects of stem cell therapy were in addition to current standard treatments for heart failure,” said Perin. “For the first time, the known anti-inflammatory mechanism of action of these cells may be linked to a cause-and-effect benefit in heart failure. Stem cells worked locally in the heart, and they also helped blood vessels throughout the body. “

Perin and his colleagues believe more research is needed to better understand how these stem cells may affect the course of heart failure progression and how these therapies can be directed to the groups of patients who might benefit the most from them. advantages.

Limitations of the search include the selection of endpoints commonly used in heart failure studies. The results of the study suggest that traditional endpoints associated with hospitalization for recurrent heart failure do not fully reveal the benefits or mechanisms of these stem cells on heart attacks, strokes, and death in patients. patients with chronic heart failure.

Co-authors are Barry H. Greenberg, MD; Kenneth M. Borow, MD; Timothy D. Henry II, MD; Farrell O. Mendelsohn, MD; Les R. Miller, MD; Elizabeth Swiggum, MD; Eric D. Adler, MD; Christopher A. James, Pennsylvania; and Silviu Itescu, MD Author disclosures are listed in the abstract.

The study was funded by Mesoblast Inc.

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