The effects of intracoronary delivery of mononuclear bone marrow cells in patients with myocardial infarction: a two year follow-up results

Background: Transplantation of bone marrow stem cells (BMSC) is a new method of prevention of left ventricular (LV) remodelling in post-infarction patients. Studies published to date point to LV systolic and diastolic function improvement following this therapy however only a few studies assessed the long-term effects of BMSC. Aim: To assess the 2 year prognosis in patients with anterior myocardial infarction (MI) treated with BMSC transplantation in the acute phase. Methods: The study group consisted of 60 patients with first anterior ST-segment elevation MI (STEMI), treated with primary percutaneous angioplasty, with baseline LV ejection fraction (LVEF) < 40%, who were randomly assigned to undergo BMSC transplantation on day 7 of the STEMI (40 patients, BMSC group) or to receive standard treatment (20 patients, control group). In all the patients echocardiography was performed at baseline and after 1, 3, 6, 12 and 24 months. The composite end-point (death, MI, admission for heart failure or repeat revascularisation) was assessed after 2 years of follow-up. Results: Absolute increase of LVEF compared to baseline values was higher in the BMSC group than in the control group. The LVEF increase in BMSC group at 1 month was 7.1% (95% CI 3.1-11.1%), at 6 months - 9.3% (95% CI 5.3-13.3%), at 12 months - 11.0% (95% CI 6.2-13.3%) and at 24 months - 10% (95% CI 7.2-12.1%). In the control group, LVEF increase was 3.7% (95% CI 2.3-9.7%) at 1 month, 4.7% (95% CI 1.2-10.6%) at 6 months, 4.8% (95% CI 1.5-11.0%) at 12 months and 4.7% (95% CI 1.4-10.7%) at 24 months. The composite end-point occurred significantly more frequently in the control group (55%) than in the BMSC group (23%): OR 2.72; 95% CI 1.06-7.02, p = 0.015. Conclusions: Treatment with mononuclear bone marrow cells on day 7 of the first anterior MI in patients with significant baseline systolic dysfunction improves 2-year outcome.