Figure 4 Transplantation of beating human embryonic stem cell (hESC)‐derived cardiomyocytes (hESCMs) attenuated the classic course of left ventricular systolic dysfunction complicating extensive anterior myocardial infarction. During 1 month of follow‐up, fractional shortening was increased by 4 (12)% in cell‐treated animals and decreased by 39 (10%) in controls (A). In addition, hESCMs attenuated scar thinning as scar thickness was decreased by 3 (8)% in cell‐treated animals and by 12 (4)% in controls (p = 0.2; B).