Abstract 1976: Characteristics and Distribution of the Scar Tissue Detected by Magnetic Resonance Imaging may Predict Ventricular Tachycardia in Patients with Advanced Heart Failure
Introduction: Contrast-enhanced magnetic resonance imaging (CMR) reveals scar tissue as an enhanced area. Non-transmural scar regions may link to a scar-related reentrant ventricular tachycardia (VT).
Methods: CMR was performed in 46 patients with advanced heart failure (dilated cardiomyopathy [DCM]-30, ischemic cardiomyopathy [ICM]-16; 36 males, 65±12 yrs; EF 28±12 %). Twenty-one patients (46 %) had documented sustained VTs. The scar volume (%; the percentage of the total scar volume) was obtained using MRI software. CMR images were also scored visually according to a 17-segment model (transmural score: 0= no damage, 4= transmural scar). The total number (No.) of segments with a transmural score of 4 (transmural scar) and transmural score of 1–3 (non-transmural scar), and the percentage of segments with non-transmural scar were obtained. The CMR parameters and clinical arrhythmic events were compared between the patients with DCM (DCM-Gr) and ICM (ICM-Gr).
Results (Table⇓): In the DCM-Gr, the scar was usually non-transmural, which presented mainly in the mid-wall layer and was characterized by a patchy distribution. The scar volume and total No. of segments with non-transmural scar were greater in DCM patients with VT than in those without. In contrast, patients in the ICM-Gr had transmural or subendocardial enhancement in the territory of coronary arteries, and the scar volume was smaller in ICM patients with VT than in those without. However, the total No. of segments with non-transmural scar and percentage of segments with non-transmural scar were greater in ICM patients with VT than in those without. In the VT patients in both Grs, non-transmural scar was always found at the VT exit site.
Conclusions: CMR is useful for assessing the characteristics and distribution of myocardial scar. A wider and greater distribution of the non-transmural scar may provide the potential substrate for reentrant VTs in patients with advanced heart failure.