Stem Cell Infusions Can Regenerate Heart Tissue

A small scale study of 11 patients has revealed that stem cells injections can reduce scar tissue and improve heart function following a heart attack

One of the biggest challenges in dealing with a heart attack is the deterioration in heart function following the event – primarily caused by the production of scar tissue that inhibits proper function. Curiously, babies who have experienced heart failure early on typically lose their scar tissue by adolescence. One theory is that residual stem cells can help repair and regenerate the heart after injury, and that a similar infusion into adult hearts may accomplish a similar feat. 

A new trial

In a small study involving 11 patients, stem cells from a healthy donor were injected near to scar tissue during bypass surgery. All patients were taken from a high risk group experiencing heart failure, with a 70% annual mortality rate. 

What were the results? 

The injections caused a 40% reduction in scar tissue. This is significant in itself, as scar tissue was previously believed to be permanent. 24 months after treatment there was a judged 30% improvement in heart function and 70% improvement in quality of life. 36 months after treatment, all patients were still alive and none had experienced any remissions or further events. 

“Quite frankly it was a big surprise to find the area of scar in the damaged heart got smaller. It’s an early study and it’s difficult to make large-scale predictions based on small studies, but even in a small study you don’t expect to see results this dramatic. These are 11 patients who were in advanced heart failure, they had had a heart attack in the past, multiple heart attacks in many cases. The life expectancy for these patients is less than two years, we’re excited and honoured that these patients are still alive”

Veins taken from the leg are typically used in bypass surgery 

Looking ahead

The company providing the treatments is Celixir, and the therapy is called Heartcel ™ – involving immunomodulatory progenitor (iMP) cells. Phase 3 trials are now set to begin in 2017. While the infusion came at the same time as bypass surgery, which makes it hard to determine exactly how much the stem cells helped themselves, the reduction in scar tissue is unparalleled and certainly warrants further study. 

“This very small study suggests that targeted injection into the heart of carefully prepared cells from a healthy donor during bypass surgery, is safe. It is difficult to be sure that the cells had a beneficial effect because all patients were undergoing bypass surgery at the same time, which would usually improve heart function. A controlled trial with substantially more patients is needed to determine whether injection of these types of cells proves any more effective than previous attempts to improve heart function in this way, which have so far largely failed”

Read more at The Guardian