Intramyocardial transplantation of mesenchymal stromal cells for chronic myocardial ischemia and impaired left ventricular function: Results of the MESAMI 1 pilot trial

International audienceBackground: The MESAMI 1 trial was a bicentric pilot study designed to test the feasibility andsafety of intramyocardially injected autologous bone marrow-derived mesenchymal stromal cells(MSCs) for the treatment of ischemic cardiomyopathy.Methods and Results: The study included 10 patients with chronic myocardial ischemia, leftventricular (LV) ejection fractions (EFs) of ≤35%, and reversible perfusion defects who were on stableoptimal medical therapy and were not candidates for revascularization. MSCs (mean: 61.5×106 cellsper patient) were injected into 10-16 viable sites at the border of the LV scar via a NOGA-guidedcatheter. Both primary endpoints, feasibility (successful harvest, expansion, and injection ofautologous MSCs) and safety (absence of severe adverse events [SAEs]) were met in all 10 patients atthe 1-month follow-up time point, and none of the SAEs reported during the full 2-year follow-upperiod were attributable to the study intervention. The results of secondary efficacy endpoint analysesidentified significant improvements from baseline to Month 12 in LVEF (29.4±2.0% versus35.7±2.5%; p=0.003), LV end-systolic volume (167.8±18.8 mL versus 156.1±28.6 mL; p=0.04), 6-minute walk test and NYHA functional class.Conclusions: Our results suggest that autologous MSCs can be safely administered to the hearts ofpatients with severe, chronic, reversible myocardial ischemia and impaired cardiac function and maybe associated with improvements in cardiac performance, LV remodeling, and patient functionalstatus. A randomized, double blind, multicenter, placebo-controlled clinical trial (MESAMI 2) willevaluate the efficacy of this treatment approach in a larger patient population.Clinical Trial Registration: Unique identifier: NCT0107692