{
  "abstract": "Introduction Risk stratification in patients with systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH) is crucial for optimizing treatment and improving outcomes. It remains uncertain whether the diffusing capacity of the lunge for carbon monoxide (DLCO) is sensitive to change and whether longitudinal DLCO measurements after SSc-PAH diagnosis provide prognostic information.Material and Methods Eligible patients were identified from the Oslo University Hospital (OUH) systemic sclerosis (SSc) cohort. We included patients who underwent right heart catheterization (RHC) between 2005 and 2020. All fulfilled the 2022 ESC/ERS guideline criteria for the diagnosis of PAH (1). Patients with DLCO% measured at baseline (+/- 3 months from PAH diagnosis) and at 12 months (+/- 3 months) were eligible. DLCO% change was defined as an increase (at least a 5% rise), a decrease (at least a 5% decline), or stable (within +/- 5%). Time zero was the PAH diagnosis (RHC date); time-to-event was measured from diagnosis to death, with patients alive at last follow-up censored. The primary outcome was all-cause mortality, and survival was assessed using Kaplan-Meier curves.Results We identified 106 SSc-PAH patients in the OUH-SSc cohort, of whom 54 (51%) had DLCO% measurements available at both baseline and 12 months. The mean age was 65 years; 43 (80%) were female, and 28 (61%) were anti-centromere antibody positive. The mean disease duration was 9.6 years (SD 9.9), with 6.6 years (SD 9.8) in the increased DLCO group, 11.3 years (SD 12.2) in the decreased group, and 9.7 years (SD 8.5) in the stable group. At baseline, the mean six-minute walk distance was 412 m (SD 121), DLCO% was 47 (SD 15), and mPAP was 33.2 mmHg (SD 12.4).At 12 months; 10 (19%) patients had an increase in DLCO%, 17 (32%) had a decrease, and 27 (50%) remained stable. During a mean follow-up period of 98 months, 53 patients (56%) died. One-, three-, and five-year survival was 100%, 100%, and 71% in the increase group; 100%, 76%, and 57% in the decrease group; and 100%, 93%, and 71% in the stable group.Conclusions Our findings suggest that DLCO% is sensitive to change after PAH-diagnosis. Patients without early DLCO% decline showed a trend towards improved survival. DLCO% may therefore serve as a potential prognostic marker in patients with SSc-PAH.Abstract P.133 Figure 1",
  "authors": [
    {
      "affiliations": [
        "University of Oslo, Institute of Clinical Medicine, Oslo, Norway"
      ],
      "name": "Håvard Fretheim"
    },
    {
      "affiliations": [
        "University of Oslo, Institute of Clinical Medicine, Oslo, Norway",
        "Oslo University Hospital, Department of Rheumatology, Oslo, Norway"
      ],
      "name": "Hilde Bjøkekjær"
    },
    {
      "affiliations": [
        "Oslo University Hospital, Department of Rheumatology, Oslo, Norway"
      ],
      "name": "Øyvind Midtvedt"
    },
    {
      "affiliations": [
        "Lillehammer Hospital for Rheumatic Diseases, Lillehammer, Norway"
      ],
      "name": "Thao Nguyen"
    },
    {
      "affiliations": [
        "Lillehammer Hospital for Rheumatic Diseases, Lillehammer, Norway"
      ],
      "name": "Yi Hu"
    },
    {
      "affiliations": [
        "Oslo University Hospital, Department of Cardiology, Oslo, Norway"
      ],
      "name": "Arne"
    },
    {
      "affiliations": [
        "Oslo University Hospital, Department of Cardiology, Oslo, Norway"
      ],
      "name": "Andreassen"
    },
    {
      "affiliations": [
        "Oslo University Hospital, Department of Pulmonology, Oslo, Norway"
      ],
      "name": "Phuong Phuong Diep"
    },
    {
      "affiliations": [
        "Oslo University Hospital, Department of Rheumatology, Oslo, Norway"
      ],
      "name": "Torhild Garen"
    },
    {
      "affiliations": [
        "University of Oslo, Institute of Clinical Medicine, Oslo, Norway",
        "Oslo University Hospital, Department of Rheumatology, Oslo, Norway"
      ],
      "name": "Emily Langballe"
    },
    {
      "affiliations": [
        "University of Oslo, Institute of Clinical Medicine, Oslo, Norway",
        "Oslo University Hospital, Department of Rheumatology, Oslo, Norway"
      ],
      "name": "Øyvind Molberg"
    },
    {
      "affiliations": [
        "Oslo University Hospital, Department of Rheumatology, Oslo, Norway",
        "University Hospital Zurich, University of Zurich, Deparment of Rheumatology, Zurich, Switzerland"
      ],
      "name": "Anna-Maria Hoffmann-Vold"
    }
  ],
  "title": "P.133 Change in DLCO over time as a predictor of mortality in SSc-PAH",
  "uid": "8af374f7-2264-5e5a-8cbc-03e723eaf336"
}