Cardiac repair following infarction

Scar tissue that appears following myocardial infarction (MI) consists of persistent, metabolically active and contractile myoFb that reside within its fibrillar collagen scaffolding nourished by a neovascular network. Understanding the evolution and maturation of this tissue, including the architecture of its fibrillar collagen scaffolding and the composition and behavior its vascular network, will be essential if today's interest in rebuilding the infarcted heart is to prove successful. Whether by the grafting of exogenous cardiomyocytes, derived from fetal heart muscle cells or stern cells, or by the homing and transdifferentiation of bone marrow-derived progenitor cells into cardiomyocytes, rebuilt myocardium must ultimately consist of anatomically appropriate, viable and functional myocardial tissue. Such "tissue engineering" will take place in the interstices of the living infarct scar. When and how best to accomplish this goal should prove interesting challenges.