Intramyocardial Bone Marrow Stem Cells in Patients Undergoing Cardiac Surgical Revascularization

Bone marrow stromal or stem cells (BMSCs) remain a promising potential therapy for ischemic cardiomyopathy. The primary objective of this study was to evaluate the safety and feasibility of direct intramyocardial injection of autologous BMSCs in patients undergoing transmyocardial revascularization (TMR) or coronary artery bypass graft surgery (CABG).

A phase I trial was conducted on adult patients who had ischemic heart disease with depressed left ventricular ejection fraction and who were scheduled to undergo TMR or CABG. Autologous BMSCs were expanded for 3 weeks before the scheduled surgery. After completion of surgical revascularization, BMSCs were directly injected into ischemic myocardium. Safety and feasibility of therapy were assessed. Cardiac functional status and changes in quality of life were evaluated at 1 year.

A total of 14 patients underwent simultaneous BMSC and surgical revascularization therapy (TMR+BMSCs = 10; CABG+BMSCs = 4). BMSCs were successfully expanded, and no significant complications occurred as a result of the procedure. Regional contractility in the cell-treated areas demonstrated improvement at 12 months compared with baseline (TMR+BMSCs Δ strain: -4.6% ± 2.1%; P = .02; CABG+MSCs Δ strain: -4.2% ± 6.0%; P = .30). Quality of life was enhanced, with substantial reduction in angina scores at 1 year after treatment (TMR+BMSCs: 1.3 ± 1.2; CABG+MSCs: 1.0 ± 1.4).

In this phase I trial, direct intramyocardial injection of autologous BMSCs in conjunction with TMR or CABG was technically feasible and could be performed safely. Preliminary results demonstrate improved cardiac function and quality of life in patients at 1 year after treatment.