domingo, 29 de agosto de 2010

The STAR-heart study: The acute and long-term effect of intracoronary stem cell transplantation in chronic heart failure

Bone marrow stem cell therapy improves ventricular performance, quality of life and survival in patients with chronic heart failure, according to results from the STAR-heart study. Professor Bodo-Eckehard Strauer, from the Cardiology Department, University of Duesseldorf, Germany, said that, although stem cells from bone marrow had been used in several thousand patients as regenerative therapy, there were still many unresolved questions, notably the quantitative amount of improvement in ventricular function, and the long-term effects in chronic heart failure. Both these questions were addressed by the STAR-heart study.
The study comprised 391 patients with chronic heart failure as a result of ischaemic heart disease (following myocardial infarction), with diagnosis defined by a left ventricular ejection fraction (LVEF) of 35% or less. Of these, 191 patients (with a mean NYHA class 3.22) agreed to have intracoronary bone marrow stem cell therapy, which was offered them between 2003 and 2005. The control group (mean NYHA class 3.06) consisted of 200 patients with comparable LVEF who did not have stem cell therapy.
The bone marrow was taken from the patient's iliac crest (at the top of the pelvic bone) and mononuclear cells isolated and identified. The cells were directly infused into the infarct-related artery via an angioplasty balloon catheter. Inflation of the balloon was important to prevent black-flow of the cells and extend the time for the cells to migrate into the infarct area. (Intravenous administration of stem cells allows only a small proportion of cells to reach the infarct region.)
With haemodynamic assessments taking place between three months and five years after the bone marrow cell therapy, there was a significant improvement in LVEF, cardiac index, exercise capacity, oxygen uptake, and LV contractility. Moreover, the beneficial effects of the bone marrow cell therapy seen at the first three-month evaluation were continued at 12 and 60 months - while in controls there was deterioration in LV performance.
Importantly, there was a significant decrease in long-term mortality in the stem-cell treated patients compared with the control group. Within a median follow-up time of 4.6 years, seven patients died in the bone marrow cell-treated group, equivalent to an average mortality rate of 0.75% per year. In the control group the average mortality rate was 3.68% per year (32 patients died within a median follow-up time of 4.87 years).
Commenting on the outcome, Professor Strauer said: "Despite progress in its medical treatment, heart failure is still a growing public health problem, with a high rate of cardiovascular complications and mortality. First-line treatment of chronic heart failure mainly aims to prevent the deterioration of heart function, which has often started following myocardial infarction. "Nevertheless, these conventional treatments for heart failure resulting from MI do not attempt to correct the underlying cause, which is usually the loss of functional myocardial tissue - and prognosis remains poor. That's why in these particular cases there is a need for strategies aimed at regeneration and tissue repair.
"Our study suggests that, when administered as an alternative or in addition to conventional therapy, bone marrow cell therapy can improve quality of life, increase ventricular performance, and increase survival. Intracoronary therapy has been shown to be effective in acute myocardial infarction, and the STAR-heart study now indicates its efficacy in chronic heart failure."