Risk Stratification of VT / VF After Myocardial Infarction Based on Cardiac MRI 2

Implantable cardioverter-defibrillators (ICD) are currently recommended (ESC guidelines 2015) for the primary prevention of sudden cardiac death (SCD) in patients with a remote myocardial infarction (MI) and a low (≤35%) left ventricular ejection fraction (LVEF). Ventricular tachycardia (VT) and/or ventricular fibrillation (VF), which are responsible for most SCDs, result from the presence of surviving myocytes embedded within fibrotic MI-scar. The presence of these surviving myocytes, as well as their specific arrhythmic characteristics, is not captured by LVEF. Consequently, most patients with a prophylactic ICD do not present VT/VF requiring ICD therapy prior to their first-ICD battery depletion. Thus, many patients are exposed to ICD complications, such as inappropriate shocks, without deriving any health benefit. As a consequence, the current implantation strategy of prophylactic ICDs, based on LVEF, needs to be improved in post-MI patients. Stratification of the rhythmic risk after IDM is therefore still a major public health issue. Late gadolinium enhancement cardiac magnetic resonance (LGE-MRI) is a strong risk-stratifier of VT/VF risk in post- MI patients. In a recent multicenter retrospective study, the investigators showed that the presence of a critical surface of intramural scar (which is consequently neither epicardial nor endocardial) at the infarct border (measured by LGE-MRI) has a major association with the occurrence of VT/VF in post-MI patients with a LVEF≤35%. The aim of the TVScreen 2 study is therefore to validate the relevance of the MRI criterion in a new independent cohort of patients.