Risk stratification for sudden cardiac death in patients with heart failure Emerging role of imaging parameters

Background Heart failure with reduced ejection fraction is a common condition that has a poor prognosis. Accurate selection of patients with ischemic heart disease and idiopathic dilated cardiomyopathy, who are at risk of sudden cardiac death (SCD), remains a challenge. In these cases, current indications for implantable cardioverter-defibrillators (ICD) rely almost entirely on left ventricular ejection fraction. However, this parameter is insufficient. Recently, noninvasive imaging has provided insight into the mechanism underlying SCD using myocardial deformation on echocardiography and magnetic resonance imaging. The aim of this review article was to underline the emerging role of these novel parameters in identifying high-risk patients. Methods A literature search was carried out for reports published with the following terms: "sudden cardiac death," "heart failure," "noninvasive imaging," "echocardiography," "deformation," "magnetic resonance imaging," and "ventricular arrhythmia." The search was restricted to reports published in English. Results The findings of this analysis suggest that cardiac magnetic resonance imaging and strain assessment by echocardiography, particularly longitudinal strain, can be promising techniques for cardiovascular risk stratification in patients with heart failure. Conclusion In future, risk stratification of arrhythmia and patient selection for ICD placement may rely on a multiparametric approach using combinations of imaging modalities in addition to left ventricular ejection fraction.