Intramyocardial injection of autologous bone marrow-derived ex vivo expanded mesenchymal stem cells in acute myocardial infarction patients is feasible and safe up to 5 years of follow-up

Abstract

In experimental studies, mesenchymal stem cell (MSC) transplantation in acute myocardial infarction (AMI) models has been associated with enhanced neovascularization and myogenesis. Clinical data however, are scarce. Therefore, the present study evaluates the safety and feasibility of intramyocardial MSC injection in nine patients, shortly after AMI during short-term and 5-year follow-up. Periprocedural safety analysis demonstrated one transient ischemic attack. No other adverse events related to MSC treatment were observed during 5-year follow-up. Clinical events were compared to a nonrandomized control group comprising 45 matched controls. A 5-year event-free survival after MSC-treatment was comparable to controls (89 vs. 91 %, P = 0.87). Echocardiographic imaging for evaluation of left ventricular function demonstrated improvements up to 5 years after MSC treatment. These findings were not significantly different when compared to controls. The present safety and feasibility study suggest that intramyocardial injection of MSC in patients shortly after AMI is feasible and safe up to 5-year follow-up.

Fig. 1

Flow chart of patients included for MSC injection. PCI percutaneous coronary intervention, SPECT single-photon emission computed tomography

Fig. 2

Kaplan–Meier curve for event-free survival of death, MI, revascularization and admission for heart failure. Event-free survival at 5 years follow-up was comparable between MSC-treated patients and controls (P = 0.97)

Fig. 3

Individual improvements in segmental perfusion during exercise and rest after 3 months follow-up. Patients treated with MSCs showed a significant improvement in summed stress score (P < 0.01) and summed rest score (P = 0.04) when compared to baseline

Fig. 4

LV ejection fraction during follow-up for MSC-treated patients and controls. MSC-treated patients demonstrated a significant improvement in LV ejection fraction during 12 months follow-up (from 48 ± 2 to 57 ± 3 %) that was comparable to controls (45 ± 9 to 50 ± 12 %; ΔP = 0.28)