{
  "abstract": "Background Familial hyperkalaemic hypertension (Gordon syndrome) and salt-wasting Gitelman syndrome represent rare opposing inherited renal tubular disorders, yet their cardiovascular phenotypes are unknown.Objectives To define and compare the cardiovascular phenotypes of Gordon and Gitelman syndromes using multiparametric cardiovascular magnetic resonance (CMR).Methods In this prospective matched case–control study, adults with genetically confirmed Gordon syndrome (n=7), Gitelman syndrome (n=7), and healthy volunteers (HV, n=14) underwent 3-Tesla multiparametric CMR including cine imaging, myocardial strain, native T1/T2 mapping, extracellular volume (ECV), adenosine stress perfusion, late gadolinium enhancement (LGE), and phase-contrast aortic flow. Group differences were assessed using analysis of covariance adjusted for age, sex, and body size, with Tukey-adjusted post-hoc testing. Effect sizes were quantified using partial eta-squared (η 2) and Hedges’ g. Multivariate phenotypic structure was explored using principal component–linear discriminant analysis (PC-LDA).Results Participants with Gordon syndrome (71% male, 42±11 years; WNK4/KLHL3 mutations) and Gitelman syndrome (38% male, 44±16 years; SLC12A3 mutations) demonstrated distinct and opposing cardiac phenotypes.After adjustment, indexed left ventricular end-diastolic volume (LVEDVi) differed significantly between groups (ANCOVA p=0.0075; partial η2≈0.35). LVEDVi was lowest in Gitelman syndrome (72.0±4.3 mL/m2), intermediate in HV (85.5±3.1 mL/m2), and highest in Gordon syndrome (93.6±4.3 mL/m2) (figure 1A). Gitelman syndrome demonstrated significantly lower LVEDVi compared with Gordon syndrome (p=0.005) and HV (p=0.042), with large effect sizes (Hedges’ g up to −1.93).Mean left ventricular wall thickness also showed a significant group effect (ANCOVA p=0.039; partial η2≈0.26), with greater wall thickness in Gordon compared with Gitelman syndrome (adjusted difference 1.79 mm, p=0.036).Native T1 and ECV demonstrated significant overall group effects (p<0.05), with higher values in both syndromes compared with HV, consistent with diffuse myocardial remodelling (figure 1B). No focal replacement fibrosis was observed on LGE imaging, myocardial strain was preserved, and stress perfusion and myocardial perfusion reserve did not differ between groups (all p>0.05). PC-LDA demonstrated partial syndrome-specific phenotypic clustering (figure 2).Conclusions Multiparametric CMR reveals distinct, opposing, and subclinical cardiovascular phenotypes in inherited renal tubular disorders. Gordon syndrome is characterised by relative ventricular dilatation and increased wall thickness, whereas Gitelman syndrome demonstrates a lower-volume cardiac phenotype. These findings suggest that altered renal sodium handling is associated with early, diffuse myocardial remodelling, best detected using comprehensive structural and tissue-based CMR.Abstract 443 Figure 1(A) Opposing ventricular geometries in Gordon and Gitelman syndromes and (B) Multiparametric tissue characterisationAbstract 443 Figure 2Multivariate CMR phenotypic structure across Gordon syndrome, Gitelman syndrome, and healthy volunteers",
  "authors": [
    {
      "affiliations": [
        "Unit for Lifelong Health and Ageing at UCL, University College London, UK"
      ],
      "name": "Aathi Somanathan"
    },
    {
      "affiliations": [
        "Unit for Lifelong Health and Ageing at UCL, University College London, UK",
        "Institute of Cardiovascular Science, University College London, UK",
        "Inherited Cardiac Conditions Unit, Royal Free London NHS Foundation Trust, London, UK"
      ],
      "name": "Fiona T Chan"
    },
    {
      "affiliations": [
        "Centre for Kidney and Bladder Health, University College London, UK",
        "London Tubular Centre, Royal Free Hospital, London, UK"
      ],
      "name": "Elizabeth R Wan"
    },
    {
      "affiliations": [
        "Unit for Lifelong Health and Ageing at UCL, University College London, UK",
        "Institute of Cardiovascular Science, University College London, UK"
      ],
      "name": "Matthew Webber"
    },
    {
      "affiliations": [
        "Institute of Cardiovascular Science, University College London, UK"
      ],
      "name": "George Joy"
    },
    {
      "affiliations": [
        "Institute of Cardiovascular Science, University College London, UK"
      ],
      "name": "Hunain Shiwani"
    },
    {
      "affiliations": [
        "Unit for Lifelong Health and Ageing at UCL, University College London, UK",
        "Institute of Cardiovascular Science, University College London, UK"
      ],
      "name": "Constantin-Cristian Topriceanu"
    },
    {
      "affiliations": [
        "Unit for Lifelong Health and Ageing at UCL, University College London, UK",
        "Institute of Cardiovascular Science, University College London, UK"
      ],
      "name": "Matthew Stanley"
    },
    {
      "affiliations": [
        "Unit for Lifelong Health and Ageing at UCL, University College London, UK",
        "Institute of Cardiovascular Science, University College London, UK"
      ],
      "name": "Alun D Hughes"
    },
    {
      "affiliations": [
        "Institute of Cardiovascular Science, University College London, UK",
        "CMR Unit, Barts Heart Centre, St Bartholomew’s Hospital, London, UK"
      ],
      "name": "Rhodri R Davies"
    },
    {
      "affiliations": [
        "Institute of Cardiovascular Science, University College London, UK",
        "CMR Unit, Barts Heart Centre, St Bartholomew’s Hospital, London, UK"
      ],
      "name": "James C Moon"
    },
    {
      "affiliations": [
        "Centre for Kidney and Bladder Health, University College London, UK",
        "London Tubular Centre, Royal Free Hospital, London, UK"
      ],
      "name": "Keith Siew"
    },
    {
      "affiliations": [
        "Centre for Kidney and Bladder Health, University College London, UK",
        "London Tubular Centre, Royal Free Hospital, London, UK",
        "Passed away on 30th September 2024"
      ],
      "name": "Stephen B Walsh"
    },
    {
      "affiliations": [
        "Unit for Lifelong Health and Ageing at UCL, University College London, UK",
        "Institute of Cardiovascular Science, University College London, UK",
        "Inherited Cardiac Conditions Unit, Royal Free London NHS Foundation Trust, London, UK"
      ],
      "name": "Gabriella Captur"
    }
  ],
  "title": "443 Gordon vs gitelman: the deep CMR phenotype of rare inherited salt-retaining vs salt-losing tubulopathies",
  "uid": "f780722c-cdce-5c85-9660-d14cdcf4dfda"
}