{
  "abstract": "Background Vitamin K, through its role in the vitamin K-dependent activation of matrix-GLA-protein, has been suggested to have a lung-protective effect, though the mechanism is unknown. Chronic obstructive pulmonary disease (COPD) patients treated with vitamin K antagonists (VKAs) may lose this protection, thereby increasing their risk of an acute exacerbation of COPD (AE-COPD) and death. We examined this hypothesis in a nationwide cohort of COPD patients treated with VKA. COPD patients treated with direct oral anticoagulant (DOAC) served as controls.Objective To assess the association between VKA treatment and the 1-year risk of AE-COPD-related hospitalisation and all-cause mortality in patients with COPD and atrial fibrillation or flutter.Methods This nationwide, observational, register-based cohort study applied Cox proportional hazard regression models, adjusting for established confounders. HRs with 95% CIs were reported. Sensitivity analyses included complete-case analysis and inverse probability of treatment weighting (IPTW).Results A total of 7091 COPD patients were included, of whom 3455 (48.7%) received VKA treatment. A total of 1955 patients reached the endpoint, including 820 in the VKA-treated group. In the primary analysis, VKA treatment was associated with a lower risk of AE-COPD hospitalisation or death (adjusted HR of 0.87 (95% CI 0.78 to 0.98), p=0.024). The association remained in the sensitivity analyses but lost statistical significance. Complete-case analysis: adjusted HR of 0.88 (CI 0.76 to 1.01), p=0.079. IPTW analysis: HR of 0.85 (CI 0.72 to 1.01), p=0.070.Interpretation VKA treatment was associated with a reduction in risk of AE-COPD hospitalisation and mortality compared to DOAC. Sensitivity analysis was consistent with the main analysis; however, it did not reach statistical significance.",
  "authors": [
    {
      "affiliations": [
        "Copenhagen Respiratory Research, Gentofte Hospital, Hellerup, Denmark"
      ],
      "name": "Bård-Emil Vang Vang Gundersen"
    },
    {
      "affiliations": [
        "Copenhagen University Hospital Gentofte, Hellerup, Denmark"
      ],
      "name": "Anna Kubel Vognsen"
    },
    {
      "affiliations": [
        "Section of Respiratory Medicine, Department of Medicine, Gentofte University Hospital, Hellerup, Denmark"
      ],
      "name": "Josefin Eklöf"
    },
    {
      "affiliations": [
        "Section of Respiratory Medicine, Department of Medicine, Herlev Hospital, Herlev, Denmark",
        "University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark"
      ],
      "name": "Pradeesh Sivapalan"
    },
    {
      "affiliations": [
        "University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark",
        "Frederiksberg University Hospital Center for Clinical Research and Prevention, Frederiksberg, Denmark"
      ],
      "name": "Allan Linneberg"
    },
    {
      "affiliations": [
        "University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark",
        "Department of Cardiology, Herlev and Gentofte Hospital, University of Copenhagen, Hellerup, Denmark"
      ],
      "name": "Tor Biering-Sørensen"
    },
    {
      "affiliations": [
        "Section of Respiratory Medicine, Department of Medicine, Herlev and Gentofte Hospital, University of Copenhagen, Hellerup, Denmark",
        "Department of Clinical Medicine, University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark"
      ],
      "name": "Jens-Ulrik Stæhr Jensen"
    }
  ],
  "title": "COPD and vitamin K antagonism: a cohort study of 1-year all-cause mortality and risk of hospitalisation due to a severe exacerbation",
  "uid": "70fa792b-eb35-5227-bb85-2465e44ab094"
}