Stem cell mobilization therapy appears to be ineffective in repairing damage caused by heart attack

Therapy that involved bone marrow stem cells did not improve cardiac function in patients following a heart attack, according to a study in the March 1 issue of JAMA.

There has been increasing evidence that stem cells contribute to regeneration of cardiac tissue and the development of new blood vessels following a heart attack, thus opening up new prospects for stem-cell based therapies. Granulocyte colony-stimulating factor (G-CSF, a growth-factor protein) induces mobilization of bone marrow stem cells, according to background information in the article.

Dietlind Zohlnhöfer, M.D., of the Technische Universität, Munich, Germany, and colleagues conducted a randomized, double-blind, placebo-controlled study (REVIVAL-2) to assess the value of G-CSF treatment in a large group of patients following a heart attack. The 114 patients, diagnosed with ST-segment elevation acute myocardial infarction (a certain pattern on an electrocardiogram indicating a heart attack), had successful reperfusion (restoration of blood flow) to the heart by percutaneous coronary intervention (procedures such as angioplasty in which a catheter-guided balloon is used to open a narrowed coronary artery) within 12 hours after onset of symptoms. Patients were randomly assigned to receive by injection either a daily dose of 10 µg/kg of G-CSF or placebo (an inactive substance) for 5 days. The patients were treated between February 2004 and February 2005.

Treatment with G-CSF produced a significant mobilization of bone marrow stem cells. The researchers found that this did not alter infarct size (area of damage) or left ventricular function after a heart attack. "Moreover, in contrast to other studies, no increase in the risk of restenosis (narrowing again of an artery after treatment) or major adverse cardiac events was observed with G-CSF treatment," the authors write.

"The REVIVAL-2 trial had a cohort that was larger than all 3 previous trials taken together and had a relatively long follow-up period based on sensitive assessment methods of left ventricular function and infarct size. In conclusion, use of G-CSF therapy to mobilize bone marrow–derived stem cell does not improve left ventricular recovery in patients with acute myocardial infarction after successful mechanical reperfusion," they write.

Source : JAMA and Archives Journals