[Stratification of arrhythmia risk in infarction: reflexions in the light of large trials]

The identification of patients at higher risk of life-threatening ventricular arrhythmias after myocardial infarction still represents a clinically relevant problem, particularly after results of recent studies which support the efficacy of implantable cardioverter defibrillator (ICD) in reducing total mortality in patients with a previous myocardial infarction and left ventricular dysfunction, with and without additional risk markers. However, owing to the high cost of ICD therapy, an effective arrhythmic risk stratification may be desirable. The low diagnostic accuracy reported by various studies using single risk stratifiers (either invasive and non invasive) suggested a combined use of multiple parameters in order to improve the predictive power of the risk stratification algorithms. This approach, that takes into account the multifactorial genesis of malignant ventricular arrhythmias, has been demonstrated to be able to identify subgroups of patients at very high arrhythmic risk. In particular, a two-level algorithm based upon the selection of candidates to electrophysiologic study among patients with abnormal non-invasive testing, showed itself as a particularly effective tool for identification of such patients. In this paper the Authors summarize most recent results on the risk stratification protocols and the use of ICDs and provide an operative algorithm that keeps into account either aggressive and moderate approaches to patients surviving a myocardial infarction.