CRT-Pacemaker Versus CRT-Defibrillator Who Needs Sudden Cardiac Death Protection?

Patients with cardiomyopathy and impaired left ventricular (LV) ejection fraction are at risk of sudden cardiac death (SCD). In selected heart failure patients, cardiac resynchronization therapy (CRT) provides LV reverse remodeling and improves the cellular and molecular function leading to a reduced risk of ventricular arrhythmia and SCD. Consequently, some CRT candidates may not need concomitant ICD therapy. This review aimed at focusing on the residual risk of SCD in patients receiving CRT and discussing the requirement of a concomitant ICD therapy in CRT candidates. New imaging diagnostic tools may be helpful to accurately predict patient with a residual risk of SCD and who required a CRT-D implantation. Recent data highlighted that cardiac computed tomography (CT) or myocardial scar tissue analysis using contrast-enhanced cardiac magnetic resonance (CMR) was able to predict the occurrence of VA in patients with bi-ventricular pacing. Cardiac imaging and specifically myocardial scar analysis seem promising to evaluate the risk of SCD following bi-ventricular pacing and will probably be of great help in the future to accurately identify those who needs concomitant defibrillator's protection.