context: Most treatment for heart failure can only slow it down or ease your symptoms. Soon, it may be possible to fix what causes it. Doctors are testing whether stem cells can repair or replace damaged heart cells. Stem cells can grow into many different kinds of cells. You have them in organs and tissues all over your body. They divide to replace worn-out or damaged cells, and to become new stem cells. In the lab, scientists have turned stem cells into ones that make up blood vessel walls and linings, and into actual beating heart cells. Now they're trying to translate that into a treatment. Scientists have zeroed in on a few specific kinds of cells that may be helpful: Bone marrow mononuclear cells: A mixture of cells that comes from your own bone marrow. Cardiac-derived stem cells: Ones found in heart tissue. Mesenchymal stromal cells: They're usually taken from bone marrow, fat, or umbilical cord blood. Proangiogenic progenitor cells: These are in blood and bone marrow. It's not approved to treat heart failure, yet. You can get it through a clinical trial. That's when the research moves from the lab to the hospital to see if a treatment is safe and if it works. If you want to try stem cell therapy, ask your doctors if there are studies that may be a good fit for you. The National Library of Medicine has a website that helps you search for all kinds of clinical trials. Not all experimental treatments are part of a clinical trial, so make sure you understand what you're signing up for. If it's a legitimate study, you shouldn't have to pay for treatment or follow-ups. Most people testing stem cell therapy for heart failure get one treatment. Then they're checked every few months for a year or more. Not everyone in a trial actually gets stem cells. Researchers need to compare the results of the new treatment against what happens with a group of people who don't get it. Doctors are testing several different methods of giving people stem cells: Intramyocardial injection: Cells go right into the heart muscle, usually during another procedure like open-heart surgery, bypass surgery, or implanting a pacemaker. Intracoronary infusion: A catheter puts cells into your coronary artery. It goes into a large blood vessel in your groin and threaded through your heart. Intravenously: Cells go right into the bloodstream through a needle placed in a vein. With any of these methods, most stem cells leave the body quickly. Researchers are looking for better ways to make them âstick.â One possibility is growing them into a patch that goes directly to the damaged part of the heart. There's no way to fix heart damage that leads to heart failure. Stem cell therapy could change that. Still, it's too early to call any treatment a success. The studies done so far have been too small. They've also used very different methods. But it does look like stem cells could help repair heart tissue. In most studies, people who got them were less likely to die or go to the hospital during the study. Their hearts worked better and their quality of life was better than for people who didn't get them. It isn't clear how stem cells help. Doctors hope clinical trials and research will help them discover that. They're also hoping to answer many other questions, including: Which cells work best? Is it better to get them from a donor or the person who needs them? How should cells be handled before they're transplanted? How large should the dose of stem cells be? How often should someone get them? What's the best way to deliver the treatment? If you are interested in joining a trial, talk to your doctor.