Risk stratification after myocardial infarction. Clinical evaluation before discharge.

Risk stratification after an acute myocardial infarction suffered a remarkable evolution in the last few years. These improvements were mainly related to the development of reperfusion strategies that changed radically the way we managed acute myocardial infarction. Risk stratification in the reperfusion era occurs in three according to time from admission: Phase I (first 24 hours), Phase II (days 2 to 5), and Phase III (predischarge). In the last years the development of new technologies permitted the study of areas not usually explored in risk stratification, as heart rate variability (autonomic system activation), and signal-averaged electrocardiogram (arrhythmia's substrate). However, risk stratification is an issue that is far from being closed, a lot of controversy still exists in some areas, and new frontiers are emerging in front of us.