Novel Therapy For Cardiomyopathy : Patient’s Own Thigh Muscle Cells

Myoblast cell sheets derived from the patient’s skeletal muscle in the thigh and grafted onto the heart surface have shown encouraging results including improved heart function and exercise tolerance and could be a viable option to treat heart failure, according to a team of Japanese scientists. Reason For the Study

The research team feels that existing therapies for heart failure including medications, pacemaker implantations or even heart transplants are not effective or viable longterm options. Rather, they feel that muscle regenerative treatment using the patient’s own skeletal muscle cells might be a safe and feasible longterm option.

Methods of the Study

A total of 27 patients suffering from cardiomyopathy from various causes, were enlisted for this Phase I Clinical Study. They were found to have heart failure (New York Heart Association functional class II or III) with reduced heart function and limited exercise capacity, and had received maximum possible therapy without much improvement.

In this scenario, the research team transplanted scaffold free muscle cell sheets derived from the patient’s own thigh muscle on to the surface of the patient’s heart by means of a surgical procedure. No other interventions were made as part of the treatment.

Findings of the Study

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All the patients were tracked over the year following the transplant. The notable findings included the following.

• The procedure was safe with no major complications from the procedure. Specifically no serious heart rhythm disturbances (arrhythmias) were noted in the patients.
• There was marked improvement in heart function with better exercise capacity including better performance in the Six-Minute Walk Test which tests exercise capacity.
• Levels of B-type natriuretic peptide (BNP) levels went down. BNP is a hormone secreted by heart, the levels of which increase in heart failure and decrease when heart function improves.
• Left ventricular stress decreased and left ventricular function improved notably.

What is Cardiomyopathy?

Cardiomyopathy is a disease of the heart muscle which affects the ability of the heart to effectively pump blood. With progression, the patient develops shortness of breath, chest pain, swelling of legs and feet, and severe limitation of routine activities. With progression of the disease, the patient goes into heart failure.

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Current treatment involves medications to improve heart function and relieve symptoms, pacemaker implantation, surgery and in extreme cases a heart transplant.

Limitations Of Other Stem Cell Therapies in Heart Muscle Regeneration

With major advances in stem cell research in the last decade, various cell therapies have been tried hoping to regenerate heart muscle cells. The notable observations emerging from stem cell research in relation to heart muscle regeneration have been the following.

• Cell therapy is a safe, albeit modestly effective in improving heart function, probably due to certain chemicals released by these cells that exert a slight local (paracrine) effect on the heart tissue to improve its function.
• Adult bone marrow stem cells have only limited capacity to differentiate into heart muscle cells.
• Embryonic stem cells may be a better option but ethical issues surrounding their use is a major stumbling block in stem cell research.
• Goal of future research should involve use of endogenous stem cells that are capable of differentiating into heart muscle cells.
• Additionally, studies have shown that cell-sheet transplant on to the surface of the heart is more effective than cell injections in maximizing the paracrine effect exerted by them to improve heart function.
• Use of scaffolds for tissue regeneration have been found to be associated with complications such as inflammatory response, biodegradability and compatibility issues.

Gaining experience from previous studies and research, the current study used the patient’s own thigh muscle (endogenous) cells to generate skeletal myoblast cell sheets. Also they transplanted (avoiding injections which were not as effective) scaffold free cell sheets onto the surface of the patients heart surgically.

In conclusion, the results of the current study seem highly encouraging and justify further follow-up of patients and conducting larger trials to establish the efficacy of autologous muscle cell-sheet transplant in the treatment of heart failure due to cardiomyopathy.

References:

1. Phase I Clinical Trial of Autologous Stem Cell–Sheet Transplantation Therapy for Treating Cardiomyopathy - (http://jaha.ahajournals.org/content/6/4/e003918)
2. Stem cell patch shows early promise in treating heart failure - (http://newsroom.heart.org/news/stem-cell-patch-shows-early-promise-in-treating-heart-failure?preview=060f)
3. B-type Natriuretic Peptide (BNP) Blood Test - (https://my.clevelandclinic.org/health/articles/b-type-natriuretic-peptide-bnp-bloodtest)
4. Autologous Skeletal Myoblast Sheet Therapy for Porcine Myocardial Infarction Without Increasing Risk of Arrhythmia - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4733831/)
5. Stem Cell Therapy for Heart Failure - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3846071/)
6. Treatments and drugs - (http://www.mayoclinic.org/diseases-conditions/cardiomyopathy/basics/treatment/con-20026819)

Source-Medindia