Study suggests intramyocardial injection of cells from bone marrow might be an alternative for heart transplantation

Aug 30 2004

Cardiovascular disease remains the leading cause of morbidity and mortality around the world and patients with end-stage ischemic heart failure carry the highest morbid-mortality rate.

Although heart transplant improves the outcomes of selected patients, the donor heart availability has limited its widespread utilization. Autologous bone marrow mononuclear cells transplantation through intramyocardial injections has been used in very initial clinical trials with promising results for treating these patients.

Our study was carried out at Pró-Cardíaco Hospital with the financial support of the Filantropic Foundation for Teaching and Researching of Pró-Cardíaco Hospital (PROCEP), in Rio de Janeiro, Brazil. The catheter-based injection system (NOGA system, Cordis Johnson&Johnson) was handled by Dr Emerson Perin from Texas Heart Institute, Houston, who was the co-principal investigator in this study.

Twenty-one patients were enrolled in this clinical trial started in December 2001, which was conducted at Pró-Cardíaco Hospital, in Rio de Janeiro, Brazil, in a partnership with Texas Heart Institute, Houston, and the Federal University of Rio de Janeiro.

It is important to emphasize that this trial was preceded by experimental models developed in partnership with the Federal University of Rio de Janeiro, granted by the Brazilian Ministry of Science and Technology. The clinical trial was approved by the Hospital Pró-cardíaco ethics committee and the Brazilian Research Ethics Council.

All patients had severe ischemic heart failure not amenable to any revascularization procedure. Fourteen patients were submitted to injections of autologous bone marrow mononuclear cells into myocardial safely, as our previously published data. The seven other patients served as a comparison or control group, and did not receive injections up to one year follow up. Our main objective was to create new small vessels in myocardial areas that were not receiving enough blood supply and because of that were contracting badly.

According to our published results, the treated patients had a significant 71% reduction in the amount of cardiac muscle with impaired blood supply and an improvement in the mechanical function, compared to the control group.

We came to this ESC Congress to report results from a subgroup of 5 treated patients that were already listed for heart transplantation and we could observe the same benefit that was seen in the entire group, including functional capacity and quality of life improvement.

We had already reported a six month follow up of such five patients in the 2003 ESC Congress, but there were concerns about the fading of benefits initially observed.

Nevertheless it is intriguing that the exercise capacity not only improved significantly but also reached such threshold that 4 from 5 patients were no longer eligible for cardiac transplantation up to one year follow up.

We have an ongoing post-mortem anatomopathological analysis and immunohistochemical findings from one patient who died at 11 months follow up due to stroke (not from the heart transplantation list) that will give us further understanding of cell mechanisms and behavior after transplantation in humans.

My words from 2003 regarding the social relevance of this finding still seems to be very promising since there is not a single heart transplant program anywhere in the world which is able to treat all the patients who need it.

We all are eagerly awaiting larger clinical trials that could confirm our results, which could lead to a revolutionary treatment for all these end-stage patients on the heart transplantation waiting list.

This release accompanies both a presentation and an ESC press conference given at the ESC Congress 2004.