5 million patients suffer from heart failure in EEUU, 500,000 new patients every year, and the expected survival is 35% (class3/4) at 5 years .The current treatment options include medications, cardiac resynchronization therapy, destination VAD therapy and cardiac transplantation.
In March 2003 we started the first clinical trial to compare patients with an OPCAB operation alone vs. OPCAB plus autologousÂ stem cells (CD 34+ CD45-) implanted by direct surgical application.Â At 6 months, we found that the second group improved their ejection fraction more than 30% compared with the patients that received OPCAB alone. In the next series, we used direct surgical application of autologous stem cells (CD 34 + CD 45 -) not only by sternotomy but also minimally invasively through a scope.Â Additionally in January 2005 we did another trial in 10 patients where we used for the first time direct surgical implantation of embryofetal stem cells between 5 to 12 weeks of gestation.
The operative mortality for the 29 patients that received autologous stem cells from different approaches was 1 patient. In the embryofetal group, the operative mortality was zero.
In the long term at 4 years, the mortality for the autologous group was 4 patients: 3 from cardiac causes and 1 from pulmonary infection. The initial average EF was 30% and, at 4 years, 38% for the ischemic patients and 27% and 36% for the patients with idiopathic cardiomyopathy. TheÂ survival at 4 years was 90% for the total series. Â
In the group of patients who received embryofetal stem cells, the initialÂ mortality was 0 % and in the long term 4 patients died: 3 for cardiac causes and 1 from diabetes complications The average initial EF was 26% and at 2 years and 7 months increased to 37% The survival is 60%.
In conclusion, direct surgical stem cell implantation is an alternative for heart failure patients.Â Both types of cells work, apparently for different mechanisms:Â the autologous cells by a paracrine effect and angiogenesis and the embryofetals by making new cells (in 4 of the embryofetal cell patients we achieved total remodeling of the ventricle in 3 months).
More studies are needed to confirm these initials observations and learn more about the type of cell in each situation, but without doubt we can say that both improve myocardial function and cellular activity. Surgical epicardical injection in the beating heart also improves the clinical symptoms of angina and heart failure, is safe and non-arrhythmogenic with sustained improvements of the EF in the long term. In conclusion, we think that direct surgical injection of stem cells is an alternative for many patients with heart failure.