Study Reference No of Patients No Cells Undergoing CABG Delivery Route Outcomes [85,89] 1 800x106 Yes IM NYHA class, LVEF & tissue viability improved. No arrhythmias. Graft survived up to 1.5 years. Cells had skeletal muscle phenotype & aligned in parallel with cardiomyocytes. No connections formed. [90,92] 8 871x106 Yes IM LVEF, tissue viability & contractility, & NYHA score improved. 5 patients developed VT. [87] 4 300x106 No IM <1% myoblast survival, no inflammation, increased vessel density, cells aligned in parallel with myocardium. 4 patients developed arrhythmias. [89] 11 221x106 Yes IM LVEF, tissue viability & contractility, & NYHA score improved. 1 patient developed VT. [91] 9 4x105-5x107 Yes IM LVEF & contractility improved. VT observed in first 2 patients (7 patients received prophylaxis). [88] 9 1x108 No Percutaneous transcoronary-venous Limited LVEF improvement. NYHA score improved. VT developed in 1 patient not receiving prophylaxis [93]   (randomized controlled) n=12 SMs; n=11 controls   30x106-600x106 No Endovascular transcatheter 1 patient in control and 2 patients in treatment group developed VT. NYHA score improved. No effect on myocardial viability or function. SMs skeletal myoblasts; CABG coronary artery bypass graft; IM intramyocardial; NYHA New York heart association; LVEF left ventricular ejection fraction; VT ventricular tachycardia

Table 2: Key outcomes of phase-1 safety and feasibility trials with skeletal myoblasts.