Abstract 4138824: Late Gadolinium Enhancement in the Basal Left Ventricle is Associated with Ventricular Arrhythmias in Patients with Pathogenic Titin Variants

Circulation, Volume 150, Issue Suppl_1, Page A4138824-A4138824, November 12, 2024. Introduction:Pathogenic titin (TTN) variants are associated with malignant ventricular tachycardia (VT) that often arises from fibrosis in the basal LV and may occur before severe LV systolic dysfunction. Late gadolinium enhancement (LGE) can identify the substrate for VT, but measurement of LGE in the basal LV is technically challenging. As genetic testing identifies more patients with earlier stages ofTTNcardiomyopathy, methods are needed to stratify their risk for malignant VT.Hypothesis:LGE burden in the basal LV is greater in patients with pathogenicTTNvariants compared to controls, and is associated with a higher risk of malignant VT.Methods:Patients with early-onset AF and/or ventricular arrhythmias (VAs) unrelated to ischemic heart disease underwent genetic sequencing. Cases had pathogenic or likely-pathogenic (P/LP) rareTTNvariants. Controls had no P/LP variants in cardiomyopathy or arrhythmia genes and were matched by age, sex, and whether they had predominately AF or VAs. Cardiac MRIs were reanalyzed by two readers blinded to case/control status. Basal LV LGE was quantified using the 5-SD signal intensity method of 3 short axis segmented inversion recovery images 8mm apart beginning at the first segment below the LVOT. Risk of malignant VT was defined as: Low Risk (≤100 PVCs per day, no NSVT, no VT), Moderate Risk (NSVT or >100 PVCs per day), or High Risk (prior sustained VT).Results:There were 16TTNcases and 17 controls. Age (TTN53 years [Q1-Q3: 49-59]; controls 51 years [42-59]) and LVEF (TTN56% [49-62]; controls 60% [55-63]) were similar. Reanalysis identified basal LGE (defined as ≥5% burden) in 14 patients (42%) compared to only 7 (21%) in the original clinical reports. LVEF was >50% in 10 of 14 patients with LGE.TTNcases had significantly higher basal LGE burden compared to controls (TTN9.0% [4.8-13.5] vs. controls 1.4% [0.0-2.3], p

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Novembre 2024