Time course of myocardial fibrosis activity following ST elevation myocardial infarction using 68Ga-FAPI PET/MR

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main source(s): British Heart Foundation - Prof Marc Dweck Senior Fellowship, and BHF Research Excellence Award 3 for Dr Anna K Barton. Background Myocardial fibrosis is a key healing response following myocardial infarction (MI). Although scar formation MI considered complete by 12 weeks, its exact time course unknown. Fibroblast activation protein factor in fibrogenesis that expressed activated fibroblasts the myocardium MI. Hybrid positron emission tomography cardiovascular magnetic resonance (PET/MR) with radiolabelled fibroblast inhibitor (68Ga-FAPI) an emerging method to measure vivo activity. Purpose To investigate timing activity ST-elevation using 68Ga-FAPI PET/MR Methods Twenty patients underwent multi-timepoint hybrid <1, 2, 4, weeks acute They were compared prior established (>12 months) healthy controls who single-timepoint determine chronic infarcts respectively. All participants imaged 30 min administration 100–200 MBq 68Ga-FAPI-04. Infarct zone uptake was quantified tissue-to-background ratio (TBRmax) after correction blood-pool left ventricle. Comparisons between timepoints group assessed ANOVA repeated measures post hoc Bonferroni correction, groups two-tailed t-test. Results Participants predominantly middle-aged men (Table). Focal localised areas within infarct peri-infarct zones on late gadolinium enhancement imaging (Figure). In MI, there substantial consistent TBRmax values at 1, 2 4 (Table Figure). Though started decline week they remained persistently elevated had modestly increased control Conclusions Intense observed throughout first month this starts it remains markedly even several years infarction, indicating low-level feature