Heart disease is a group of conditions impacting the heart. The most common of these is coronary artery disease. When it’s not managed, heart disease can have serious complications, like heart failure or heart attack.

According to the Centers for Disease Control and Prevention (CDC), heart disease is the leading cause of death for men, women, and most racial and ethnic groups in the United States.

When you think of heart disease treatments, medications and lifestyle changes probably come to mind. But what if we could repair damage from heart disease using stem cells?

Could this be the new frontier of treatment for heart disease? Continue reading to learn more.

Our bodies are made up of a diverse amount of cell types with various shapes and functions. For example, a nerve cell has very different characteristics and tasks than a muscle cell.

All of these cell types come from stem cells, a type of cell that can create other, more specialized cells. Stem cells can also self-renew, meaning they can divide to make more stem cells.

Generally speaking, there are two types of stem cells. Let’s take a look at these now.

Adult stem cells

Adult stem cells exist in our bodies right now, but only in certain tissue types, like the bone marrow, brain, and skin. The function of adult stem cells is to replace cells that are lost through injury or regular wear and tear.

For example, hematopoietic stem cells in your bone marrow can develop into different types of blood cells in your body. Mesenchymal stem cells, also found in the bone marrow, can become muscle, bone, or fat cells.

Pluripotent stem cells

Pluripotent stem cells can become any type of cell in the human body. In nature, these stem cells are found during the early development of human embryos. These are called embryonic stem cells.

However, scientists have now found a way to reprogram some types of adult stem cells to become pluripotent stem cells. These stem cells are referred to as induced pluripotent stem cells.

Why is there so much controversy around stem cells?

In 1998, scientists developed a technique to collect pluripotent stem cells from human embryos. These embryos are about 5 days old, which is when the embryo is made up of a hollow ball of cells called a blastocyst.

The controversy focuses on the moral implications of using stem cells from human embryos.

In 2006, researchers developed a way to reprogram adult stem cells to become like pluripotent stem cells. As we mentioned earlier, these are called induced pluripotent stem cells.

Induced pluripotent stem cells aren’t exactly the same as those that come from embryos. Still, they’ve greatly lessened the need for the use of embryonic stem cells in many areas of research.

Currently, the only stem cell products approved by the United States Food and Drug Administration (FDA) are those using hematopoietic stem cells from blood or bone marrow. These stem cells are approved for transplant procedures to treat blood conditions like:

In this therapy, doctors use high dose radiation or chemotherapy to destroy cells in the bone marrow. After this, doctors infuse the stem cells into the bone marrow. The goal is for the stem cells to reestablish a bone marrow that produces healthy blood cells.

Since stem cells can become other cell types, they’re also being researched as a therapy for various health conditions. The hope is that the stem cells will be able to regenerate damaged or injured tissues.

One example is neurodegenerative conditions, such as Parkinson’s disease, multiple sclerosis, and amyotrophic lateral sclerosis (ALS). These conditions cause progressive damage to the nervous system and don’t yet have a cure.

Researchers have been able to use stem cells to generate neural cells in a laboratory. This has led to various clinical trials testing the safety and effectiveness of stem cells in treating neurodegenerative conditions.

Other conditions that stem cell therapy is being researched for include diabetes, eye conditions, and cancer.

Heart disease causes damage to heart tissue. It’s often hard for the heart to repair this damage after it has occurred.

Researchers have begun to investigate the use of stem cells to repair damage from heart disease with the hope of helping to restore heart function. But this research is still in a relatively early stage.

Studies for this type of therapy have included both pluripotent stem cells and adult stem cells. Some of the most promising results have come from using mesenchymal stem cells, a kind of adult stem cell.

Doctors can deliver stem cells by several different methods. These include:

  • direct injection into the heart
  • introduction into the coronary arteries
  • intravenous (IV) infusion

There’s still much to learn. Some examples of the many open questions include:

  • How many stem cells need to be given for treatment to be effective?
  • How well do stem cells survive after entering the heart? What can we do to improve this survival?
  • Is one treatment enough to help with tissue recovery? If not, how many treatments are needed?
  • Does the timing of the treatment matter? Is it more effective right after damage has occurred? Can it still be used when damage is months or even years old?
  • How does stem cell therapy work with existing treatments for heart disease?
  • How safe is stem cell therapy for heart disease? Are there any concerning side effects?

Is stem cell therapy for heart disease approved by the FDA?

Stem cell therapy for heart disease is not currently approved by the FDA. However, researchers are studying stem cell therapy for heart disease in clinical trials.

The only stem cell-based therapies that are currently approved by the FDA are those that use hematopoietic stem cell transplants to treat conditions affecting the blood, like leukemia and multiple myeloma.

Research snapshot

Stem cell therapy may help to repair damage from heart attacks, according to a 2020 study on mice. In the study, the mice received therapy with human stem cells following a heart attack.

Researchers found that a heart attack changed the levels of 450 different proteins in the heart. However, stem cell therapy either fully or partially reversed these changes in 65 percent of the proteins.

Researchers also found stem cell therapy to reduce major cardiac events in individuals with heart failure, according to data presented at the American Heart Association’s Scientific Sessions 2021.

The study included 537 people with heart failure. Of these people, 261 received an injection of stem cells into their heart, and 276 underwent a sham procedure. Participants were then observed for 30 months.

Compared to the control group, those that received the stem cells had a 65 percent reduction in nonfatal heart attack and stroke. However, there was no reduction in hospitalizations due to heart failure in the stem cell group.

Another important finding was that stem cell treatment reduced the number of cardiac deaths by 80 percent in people with class 2 heart failure.

The research hasn’t been without setbacks, though. A 2019 study of people with advanced heart failure and a ventricular assist device found no difference between the control group and those receiving stem cells in being able to wean participants from the device.

Researchers are still trying to evaluate the safety of stem cell therapy for heart disease. Some potential safety concerns about this type of treatment include the following:

  • Stem cells can develop into different types of heart muscle cells, which respond differently to the electrical signals that trigger the heartbeat. Many different cell types in one area could impact treatment effectiveness or cause arrhythmia.
  • Some types of stem cells have the potential to form a type of tumor called a teratoma.
  • A person’s immune system might reject the stem cells.

It will take more research, both in the laboratory and in clinical trials, to fully understand the risks associated with stem cell therapy for heart disease.

Stem cell therapy has a lot of potential for treating various conditions, including heart disease. These therapies aim to repair damage caused by heart disease and help restore heart function.

More recent studies have found that stem cell therapy may reduce the risk of heart attack and stroke in some people with heart failure. Animal studies have suggested that it may also help reverse some damage done by a heart attack.

These findings show promise. However, there’s still a lot of research left to do into the effectiveness and safety of these interventions before they can be used on a wider scale.