American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society scientific statement on noninvasive risk stratification techniques for identifying patients at risk for sudden cardiac death: A scientific statement from the American Heart Association Council on Clinical Cardiology Committee on Electrocardiography and Arrhythmias and Council on Epidemiology and Prevention

Given the availability of therapies to prevent SCD due to otherwise fatal ventricular tachyarrhythmias, it is important to differentiate noninvasive risk stratification techniques that enhance the ability to identify SCD from total mortality. The relative ability for each of the described techniques varies, and the optimal way to combine and use these techniques in clinical practice remains unclear. Low LVEF, which is the most widely used test on which ICD intervention is recommended, does not have a particularly high discriminatory ability to identify SCD rather than non-SCD mortality. Although data exist supporting the concept that noninvasive risk stratification techniques may be useful to identify patients with low LVEF who are at low risk for SCD, this requires further testing. There are also data to support the concept that noninvasive risk stratification techniques may be useful to identify patients who do not have low LVEF who nevertheless are at substantial risk for SCD. Because most SCD occurs in this latter group, substantial effort is justified in evaluating, testing, and ultimately implementing risk stratification strategies in this group.