After acute MI, intracoronary infusion of autologous stem cells contributes to restoration of LV synchronous contraction, according to a report in the August issue of Heart.

After acute myocardial infarction, intracoronary infusion of autologous stem cells contributes to restoration of left ventricular (LV) synchronous contraction, according to a report in the August issue of Heart.

"Stem cell therapy significantly improved LV contractility compared with control treatment," Dr. Hyo-Soo Kim from Seoul National University Hospital, Seoul, Korea told Reuters Health. "But the efficacy is limited."

Dr. Kim and colleagues evaluated the value of stem cell therapy in 40 MI patients who underwent successful coronary revascularization. The patients randomly allocated to stem cell therapy were treated with granulocyte colony stimulating factor for three days to mobilize stems cells, which were collected by apheresis and then infused into the infarct-related coronary artery.

Six months after stem cell infusion, the improvement in left ventricular ejection fraction (LVEF) was significantly higher compared with the control group, the authors report, and LV synchronous contraction was markedly improved in the stem cell infusion group, but not in the control group.

In multivariate analyses, a higher degree of baseline LV dyssynchrony and treatment with stem cell therapy were independently associated with greater improvements in LV ventricular synchronous contraction.

Exercise capacity showed a significant improvement at the six-month follow-up in the cell infusion group, but not in the control group, the investigators say, and the improvement in exercise capacity correlated with the improvement in LV synchronous contraction (but not with LVEF).

"Cell therapy usually improves LV contractility by three to five per cent improvement of LVEF," Dr. Kim said, "but the improvement of synchronicity in LV contraction by cell therapy was not expected."

The use of G-CSF and stem cell infusion "may deserve evaluation in a larger, adequately powered clinical trial with the use of relevant end points," write Dr. Ketil Lunde and Dr. Svend Aakhus from Rikshospitalet University Hospital, Oslo, Norway in a related editorial.

"The search for effective cell-based therapies in myocardial infarction and appropriate end points should continue," the editorial concludes.

Heart 2008;94:995-1001,969-970