What is the optimal initiation timing of angiotensin converting enzyme inhibitor treatment for maximum benefits in acute myocardial infarction patients?

Randomized clinical trials led to the clinical recommendation that angiotensin-converting enzyme inhibitors (ACEI) should be used as standard therapy in most patients experiencing an acute myocardial infarction (AMI). However, the optimal initiation timing of treatment, as well as the exact mechanisms, have not been completely resolved, especially with the development of reperfusion strategy after AMI. Earlier initiation of ACEI might be associated with more prompt recovery of left ventricular ejection fraction due to more rapid attenuation of negative remodeling. Chin Med J 2011;124(3):464-466