ICD therapy decreases risk of sudden cardiac death in patients with HFrEF, including patients with ICM with left ventricular ejection fraction of <35%. Current ESC Guidelines for implantable cardioverter defibrillator (ICD) therapy for primary prevention of sudden cardiac death in patients with ischemic cardiomyopathy have high sensitivity and high positive predictive value. A limitation of current guidelines is low specificity and low negative predictive value. In real clinical practice, it means that less than 1/3 of patients with heart failure with reduced ejection fraction who get the ICD device for an indication of primary prevention of sudden cardiac death will receive appropriate ICD discharge. The remaining 2/3 of patients have no benefit from ICD implantation, and are exposed to risks of complications resulting from ICD implant, such as inappropriate ICD discharges, lead dislocation, or even life-threatening complications such as infectious endocarditis or myocardial perforation.