458-P: Whole Left Ventricular Cardiac MRI in High-Risk People with Type 1 Diabetes Reveals Pathological Extracellular Volume Fraction and T1 Relaxation Times

Introduction: Diffuse myocardial fibrosis is a negative CV prognostic marker. We employed advanced cardiac MRI (CMR) techniques for detailed left ventricular myocardial tissue characterization people with type 1 diabetes (PwT1D) and high CV risk. Methods: Quantitative native T1 mapping (T1) and extracellular volume fraction (ECV) calculation of the whole left ventricular myocardial volume (LVMV) was done (1.5T Avanto Fit, Siemens) in PwT1D and high CV risk (CAC score 400 and/or presence of ≥2 atherosclerotic plaques in the carotids) but without clinical diagnosis of CVD or heart failure. Percentage of LVMV above the normal values for T1 (1100 ms) and ECV (28 %) was calculated. Results: Twelve PwT1D (8/12 women) with mean (SD) range age 65 (2) 60 - 67 years, diabetes duration 36 (12) 16 - 56 years, HbA1c 7.5 (0.9) 6.0 - 8.8 %, LV EF 66 (7) 54 - 77 % were analyzed. Mean (SD) range native T1 time was 1060 (41) 996 - 1138 ms and the % of LVMV 1100 ms was 27 (11) 14 - 47 % (Fig. 1A). Mean (SD) range ECV was 28.6 (3.5) 23 - 33 % and the % of LVMV 28 % was 47 (21) 7 - 78 % (Fig. 1B). Conclusion: This is the first CMR study which has applied threshold values to native T1 and ECV data for the whole LVMV in PwT1D. We demonstrate large myocardial areas which are above the normal values. Clinical implications of our findings will require further evaluation on larger populations. Disclosure P. Novodvorsky: Speaker's Bureau; Sanofi, Boehringer-Ingelheim. Advisory Panel; Boehringer-Ingelheim. Speaker's Bureau; Novo Nordisk A/S. Research Support; Sanofi. Speaker's Bureau; Abbott, Medtronic, Berlin-Chemie AG, Viatris Inc., Novartis AG. M. Dubsky: None. N. Marhefková: None. T. Adla: None. R. Roland: None. M. Pazdernik: None. M. Haluzik: Advisory Panel; Sanofi, Novo Nordisk, Eli Lilly and Company, AstraZeneca, Bayer Inc., Johnson Merck Sanofi. Speaker's Bureau; Sanofi, Novo Nordisk. P. Garg: Consultant; Edwards Lifesciences, Anteris. Advisory Panel; Pie Medical, Medis. Funding National Institute for Research of Metabolic and Cardiovascular Diseases (Programme EXCELES, Project No. LX22NPO5104); Funded by the European Union; Next Generation EU