Mortality is increased in acute coronary syndrome (ACS) related to the extent of myocardial injury even if percutaneous coronary intervention (PCI) was successful. The development of congestive heart failure (CHF) after PCI in ACS is of prognostic interest. Non-invasive imaging plays a major role for determination of structural myocardial damage and loss of function. Secondary prevention regarding pharmacologic and non-pharmacologic therapy is dependent on myocardial function and the presence or absence of CHF. Exercise training as part of the non-pharmacological therapy plays an important role in rehabilitation after ACS according to the severity of injury.