Stem cells therapy is a safe tool for mending broken hearts

ESC Congress 2003: Stem cells – A tool for mending broken hearts?

We have shown that stem cell injections by catheters into diseased hearts are feasible and safe, even for very sick patients. Moreover, the results suggested strongly a potential ability of these cells to regenerate the arteries of the heart (called coronary arteries), and this regeneration improved the mechanical function of the heart, improving the heart failure condition of these patients. Since heart failure is a more aggressive killer than most cancers, and the fact that cardiovascular diseases are the leading cause of mortality around the world, this could be a beginning of a “new era” in cardiovascular therapy.

Our study was carried out at Pró-Cardíaco Hospital (granted by the Filantropic Foundation of Teaching and Research of Pró-Cardíaco Hospital – PROCEP), in Rio de Janeiro, with a partnership with the Federal University of Rio de Janeiro and Texas Heart Institute. The experimental models were developed by the Federal University (granted by the Ministry of Science and Technology) and the injection system used to introduce the cells into the heart was developed by Johnson&Johnson, and tested in Houston.

We enrolled 21 patients in this study. All patients had an end stage coronary artery disease, which means no possibility of proceeding to a bypass surgery or to an angioplasty (treatment of the coronary arteries using a catheter). This advanced disease in coronary arteries is responsible for damages in the heart’s muscle, characterizing a heart failure condition.

The first 14 patients were submitted to an autologous transplantation of cells from bone marrow into the cardiac muscle, aiming to create new small arteries in the heart, which would make possible a more effective supply of blood to the damaged muscle. The other 7 patients were enrolled as a control group, and were followed up during the same one year period.

Considering the safety data, there were no major adverse effects observed in this group of patients. There was one death in the control group at the second week after the enrollment. In the treated group we observed two deaths, the first at the fourteenth week and the last one up to the ninth month of follow up. Both deaths could not be considered as related to the cell procedure, as analyzed by the Steering Committee of the study. Actually, the expected mortality for these patients is around 53% in 6 months.

Considering the efficacy data, the treated patients had a significant 71% reduction of the muscle areas with impaired blood supply, while we observed an increase of this parameter in the control group. The better blood supply allowed a 40% improvement of the heart’s mechanical function only observed on treated patients.

These improvements in blood supply and mechanical function reflected on patients’ quality of life as evaluated by a specific tool for this purpose (SF-36 – a general health evaluation questionnaire). This questionnaire evaluates 8 aspects of general health and its impact on patients’ quality of life. When comparing the patients’ data at baseline to the average data of the general American population, we observed a very low score in all 8 aspects. At 8 weeks of follow up we observed an improvement in 7 of the 8 aspects, which are comparable to the general American population average.

A subgroup of 5 patients was listed for heart transplant and at the end of six months of follow up, 4 of them did not match the clinical conditions to be eligible for the procedure. These data have social relevance once there isn’t a single heart transplant program around the world which is able to treat all patients who need it.

Since this is a phase I study with a small number of patients, our findings need to be confirmed in new studies oriented to the efficacy of this procedure, as randomized, double-blind, placebo controlled trials, with a larger number of patients.

Hans Fernando Rocha Dohmann MD, MBA
Pró-Cardíaco Hospital, Rio de Janeiro
Brazil

Important: This press release accompanies both a presentation and an ESC press conference given at the ESC Congress 2003. Written by the investigator himself/herself, this press release does not necessarily reflect the opinion of the European Society of Cardiology