{
  "abstract": "Introduction Heart failure with preserved ejection fraction (HFpEF) often coexists with obesity. The impact of obesity on skeletal muscle (SkM) quality, particularly intramuscular fat infiltration (myosteatosis), is poorly elucidated. Myosteatosis represents pathological fat accumulation within SkM and may contribute to poor exercise tolerance prominent in HFpEF.Thigh magnetic resonance imaging (MRI) provides a robust surrogate of whole-body SkM composition. Proton density fat fraction imaging and water specific imaging and water specific T1 mapping (PROFIT1) is a novel MRI sequence enabling precise quantification of fat and water signals, allowing accurate quantification of SkM composition. We compared thigh intramuscular fat (IntraMF) content between obese and non-obese HFpEF patients using the PROFIT1 sequence, as a marker of myosteatosis.Methods The ISARC-HF (Imaging assessment of sarcopenia across the Heart Failure spectrum) study was a cross-sectional single-centre study recruiting patients with HFpEF, diagnosed according to ESC criteria. All participants underwent comprehensive phenotyping. IntraMF (ml) was quantified using the PROFIT1 sequence on a 3-Tesla Siemens MAGNETOM VIDA scanner. MRI acquisitions consisted of five transverse slices (slice thickness 3.5 mm) across both quadriceps. Independent sample t-test was used to compare myosteatosis between obese and non-obese HFpEF patients, with effect size calculated using Cohen’s d.Results We included 27 HFpEF patients (median age 76 (68, 83) years, 44% female, median LVEF 55(52,60) %, median BMI 34.7 kg/m 2). Of these, 70.4% (n=19) had obesity (table 1). Obese HFpEF patients demonstrated significantly higher IntraMF compared to non-obese HFpEF patients (61.3 ± 13.5ml versus 44.6 ± 10.3ml respectively, mean difference 16.6ml, 95% CI: 5.6 – 2.7, p = 0.005), with a large effect size (Cohen’s d = 1.31, 95% CI 0.40 – 2.20).Conclusion This study is the first to apply the PROFIT1 sequence to directly compare fatty infiltration of SkM between obese and non-obese HFpEF. Our findings show that obesity in HFpEF is associated with substantially increased myosteatosis, with a large effect size indicating potentially clinically relevant differences in muscle quality. Pathological fat accumulation may contribute to SkM dysfunction and exercise intolerance observed in HFpEF patients with obesity. However, limited sample size may restrict our ability to generalise these findings. Further validation is needed in larger cohorts of HFpEF, investigating obesity-related myosteatosis as therapeutic target in HFpEF, involving interventions aimed at reducing fat content.Abstract 275 Table 1Characteristics of obese HFpEF and non-obese HFpEFObeseNon-obeseAge, years70.7 ± 10.379.9 ± 13.9Female sex, n (%)9 (47%)3 (38%)South Asian ethnicity, n (%)2, 11%0BMI, kg/m240 ± 727 ± 2LVEF (%)57 ± 754 ± 6NYHA Class II (n, %)13 (68%)2 (20%)NYHA Class III (n, %)6 (32%)6 (75%)Data presented as mean ± standard deviation or percentage frequency. BMI: Body Mass Index; LVEF: Left Ventricular Ejection Fraction; NYHA: New York Heart Association.",
  "authors": [
    {
      "affiliations": [
        "Department of Cardiovascular Sciences, University of Leicester, and the NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom"
      ],
      "name": "Safiyyah Suleman"
    },
    {
      "affiliations": [
        "Department of Cardiovascular Sciences, University of Leicester, and the NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom"
      ],
      "name": "Joanna Bilak"
    },
    {
      "affiliations": [
        "Department of Cardiovascular Sciences, University of Leicester, and the NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom"
      ],
      "name": "Alice Cowley"
    },
    {
      "affiliations": [
        "Department of Cardiovascular Sciences, University of Leicester, and the NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom"
      ],
      "name": "Sarah Ayton"
    },
    {
      "affiliations": [
        "Department of Cardiovascular Sciences, University of Leicester, and the NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom"
      ],
      "name": "Shirley Sze"
    },
    {
      "affiliations": [
        "Department of Biomedical Engineering, University of Alberta, Edmonton, Canada"
      ],
      "name": "Richard Thompson"
    },
    {
      "affiliations": [
        "Department of Cardiovascular Sciences, University of Leicester, and the NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom"
      ],
      "name": "Joanne Wormleighton"
    },
    {
      "affiliations": [
        "Department of Cardiovascular Sciences, University of Leicester, and the NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom"
      ],
      "name": "Kelly Parke"
    },
    {
      "affiliations": [
        "Department of Cardiovascular Sciences, University of Leicester, and the NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom"
      ],
      "name": "Rachel England"
    },
    {
      "affiliations": [
        "Department of Cardiovascular Sciences, University of Leicester, and the NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom"
      ],
      "name": "Gerry McCann"
    },
    {
      "affiliations": [
        "Department of Cardiovascular Sciences, University of Leicester, and the NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom"
      ],
      "name": "Iain Squire"
    }
  ],
  "title": "275 Obesity is associated with increased myosteatosis in HFpEF – magnetic resonance imaging findings from ISARC-HF",
  "uid": "2ef4b688-f938-5e75-9782-73286b0aea28"
}