Stem cell therapy for heart failure is a rapidly progressing field. The objective of this study was to assess the safety, and short-term results of thoracoscopic direct injection of angiogenic cell precursors into patients with endstage cardiomyopathy. Cells were obtained from the patient's own blood, avoiding immunological concerns. The number of cells prior to injection was 29.1 +/- 18.9 x10(6). Forty-one patients with cardiomyopathy (mean age, 58.5 +/- 14.3 years) underwent stem cell injection; 21 had dilated cardiomyopathy and 20 had ischemic cardiomyopathy. Overall ejection fraction improved significantly by 4.8% +/- 7.5% at 149 +/- 98 days postoperatively. It increased from 25.9% +/- 8.6% to 28.7% +/- 9.8% in dilated cardiomyopathy, and from 26.6% +/- 5.8% to 33.6% +/- 7.8% in ischemic cardiomyopathy. New York Heart Association functional class was significantly better at 2 months in both groups. It was concluded that thoracoscopic intramyocardial angiogenic cell precursor injection is feasible and safe in patients with cardiomyopathy. The early results are good, and phase II trials are in progress.