0141: Value of cardiac magnetic resonance imaging to predict the occurrence of ventricular tachycardia in post-infarct patients

Introduction The use of implantable cardioverter-defibrillators (ICD) is recommended to prevent sudden cardiac death (SCD) in patients with a reduced (≤30-35%) left ventricular ejection fraction (LVEF) due to previous myocardial infarction (MI). Some patients, however, never receive adequate ICD intervention. We studied whether the characteristics of MI scar, as assessed by magnetic resonance imaging (MRI), could predict the occurrence of ventricular tachycardia (VT). Methods Fifty-one patients (41 men, mean age=59±11 years) with a remote (>6 months) MI and a class I primary prevention indication for ICD implantation underwent a cardiac MRI study before implantation. Delayed contrast enhancement (DCE) was used to delineate post-MI scars.On the basis of manually outlined contours of left ventricular epicardial, endocardial and scar borders, the location and transmural extent of the scar were calculated. Results VT occurred in 15 patients (29%) after a follow-up of 43±24 months. There were no statistical differences between patients who experienced VT and those who did not for demographic data, LVEF, total myocardial and MI surface. At infarct borders, MRI showed areas with intramural and/or epicardial scar in all but one patients. Epicardial scar surface (3.6±0.5 vs. 1.4±0.3 cm2; p=0.0005) and intramural scar surface (4.0±0.6 vs. 1.8±0.4 cm2; p=0.002) were greater in patients with VT. In multivariate analysis, intramural and sub-epicardial scar surface remained significantly associated with the occurrence of VT (respectively: HR, 1.28/1cm2; CI, 1.10 to 1.51; p=0.003 and HR, 1.23/1cm2; CI, 1.01 to 1.51; p=0.04). Patients with intramural scar surface>1.65 cm2 had lower 5 years VT free survival (33.8% vs. 100%; p Conclusion The presence of a critical surface of both intramural and epicardial scars at an infarct border may be key factors for the occurrence of VT after MI. Download full-size image Abstract 0141 - Figure: 3D left ventricular reconstruction