On its own, the heart cannot regenerate cells. Damage done to the heart’s tissues is therefore permanent damage, often leading to heart failure. Cardiomyoplasty, cell therapy and gene therapy are highly experimental treatment methods that seek to slow the progression of heart failure, fortifying the damaged heart with new muscle tissue or tissue taken from elsewhere in the body.
Cardiomyoplasty involves the removal of muscle tissue from one part of the patient’s body, such as the back, to be grafted onto the heart in order to strengthen it. In a typical cardiomyoplasty procedure, the patient’s latissimus dorsi muscle is removed and wrapped around the heart as a kind of “girdle.” It is then stimulated electrically to condition it to endure the heart’s relentless activity.
However, almost a decade’s worth of research has shown that, at least with current techniques, the transposed muscle may not be up to the challenge. Surgical trauma and the relentless electrical stimulation that is required to make the grafted muscle work have proven detrimental to it, causing it to deteriorate in the body. Recent improved outcomes with better stimulator technology may offer hope for cardiomyoplasty as a treatment option, but only a few investigators are pursuing it.
Cell and Gene Therapy
Cell therapy and gene therapy are more recent innovations. Cell transplantation (CT), a form of cell therapy, is a kind of controlled, artificial regeneration of damaged heart tissue (myocardium). CT involves the cultivation of new tissue from patient or donor stem cells, typically derived from bone marrow. The tissue is either seeded around the damaged heart muscle or else grafted to the heart later.
Gene therapy involves the delivery of active gene material to the heart muscle or the vasculature around it. The gene material is intended to stimulate activity in the tissues to slow the progression of heart failure. In small animal studies, researchers have been able to use gene therapy to overwhelm defective genes that were contributing to the heart’s loss of shape and strength.
Given the success of experimental applications of cell and gene therapy in animals, the potential of these treatments appears high. But the research is still in the early phases. An important question that remains yet unanswered is whether or not these therapies will actually increase the strength of the heart and relieve the symptoms of heart failure.