Gray-zone late gadolinium enhancement greatly enriches the prediction of ventricular arrhythmia; a cardiovascular MRI study

Abstract

Summary Gray-zone imaging for VT/VF is markedly predictive for both ischmic and non-ischemic patients as related to the incidence of post-implantation shock delivery. Background Sudden cardiac death in patients is predominantly caused by ventricular tachycardia (VT)/ventricular fibrillation (VF). Patients who have a low left ventricular ejection fraction (LVEF) and inducible VT during electrophysiologic study (EPS) are at risk of sudden death and may benefit from an implantable cardioverter-defibrillator (ICD) as do patients with low LVEF. However, LVEF’s primacy in predicted SCD has been questioned. Recently, cardiac MRI (CMR) has shown that a determination of myocardial core scar via late gadolinium enhancement (LGE) may predict VT/VF with greater precision than LVEF presumably due its ability to define likely sources of macro-rentry by delinieating the ‘grayzone’ myocardium. We hypothesize that LGE depiction of gray-zone scar is more predictive of VT/VF than LGE core scar assessment. Methods A consecutive, retrospective chart review was performed of patients with both a CMR exam for LGE and with post-CMR ICD implantation from 2006-2010 within 30 days. Demographic and clinical events were collected from patient charts and ICD interrogation. Standard LGE (>2SD) and gray-zone (LGE;2-3SD) was manually determined and related as a percent of LV mass to arrhythmic events and ICD therapy. Results