{
  "abstract": "Introduction: Takotsubo syndrome (TTS) is often triggered by intense emotional or physical stress, with symptoms closely resembling those of acute myocardial infarction and heart failure. The COVID-19 pandemic caused unprecedented psychological, social, and economic stress, with TTS incidence and mortality either increasing or remaining stable. Previous studies have relied on single- or multicenter data, lacking the scope to provide national-level insights. This study aimed to fill the gap by investigating the incidence and outcomes of TTS across Sweden during two distinct periods: the pre-pandemic period (January 2015 to March 2020) and the pandemic period (April 2020 to December 2022).\n\nMethods: Using the nationwide Swedish Coronary Angiography and Angioplasty Registry, we assessed the incidence rate (IR) for all patients with TTS referred for coronary angiography in Sweden. We calculated incidence rate ratios (IRRs) both before and during the pandemic using quasi-Poisson regression, adjusted for age and sex. We evaluated 30-day and 1-year mortality using multivariable Cox proportional hazards regression, accounting for clustering within hospitals.\n\nResults: We identified 3,180 patients hospitalized with TTS during the study period: 69% (2,189) pre-pandemic and 31% (991) during the pandemic. The incidence of TTS was 10% lower during the pandemic compared to the pre-pandemic period (IRR 0.90, 95% CI 0.84–0.97, P = 0.008). The cohort’s crude all-cause mortality rate was 2.73% at 30 days and 6.10% at 1 year, with no significant difference at 30 days (adjusted HR 1.12, 95% CI 0.69–1.78, P = 0.642) or one year (adjusted HR 1.05, 95% CI 0.75–1.46, P = 0.780). Compared with studies in other countries where incidence increased or remained unchanged, COVID-19 incidence was similar across the matching periods.\n\nConclusions: This nationwide observational study found a lower incidence of TTS during the pandemic compared to the pre-pandemic period, while mortality rates remained unchanged. The reduced incidence of TTS in Sweden may reflect the country’s comparatively milder pandemic control measures and more robust social security infrastructure relative to other nations.\n\nClinical trial number: Not applicable.\n\nSupplementary information: The online version contains supplementary material available at https://doi.org/10.1186/s12872-026-06889-0.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Cardiology, Sahlgrenska University Hospital, Gothenburg, Sweden",
    "Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden",
    "Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark",
    "Department of Cardiology, Örebro University Hospital, Örebro, Sweden",
    "Department of Health, Medicine and Caring Sciences, Department of Cardiology, Linköping University, Linköping, Sweden",
    "Department of Clinical Sciences, Division of Cardiovascular Medicine, Karolinska Institutet, Danderyd University Hospital, Stockholm, Sweden",
    "Department of Medicine, Heart and Vascular Theme, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden",
    "Department of Cardiology, Clinical Sciences, Lund University, Skåne University Hospital, Lund, Sweden",
    "Department of Cardiology, Umeå University Hospital, Umeå, Sweden"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 18,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "T. Gudmundsson",
      "orcid": "0009-0006-2686-8264"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "P. Petursson"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "T. Råmunddal"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "O. Angeras"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "A. Rawshani"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "O. Frobert"
    },
    {
      "affs": [
        4
      ],
      "name": "J. Alfredsson"
    },
    {
      "affs": [
        5
      ],
      "name": "C. Ekenbäck"
    },
    {
      "affs": [
        6
      ],
      "name": "L. Henareh"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "K. Skoglund"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "C. Ljungman"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "E. Bollano"
    },
    {
      "affs": [
        7
      ],
      "name": "M. Mohammad"
    },
    {
      "affs": [
        8
      ],
      "name": "H. Hagström"
    },
    {
      "affs": [
        5
      ],
      "name": "T. Jernberg"
    },
    {
      "affs": [
        7
      ],
      "name": "D. Erlinge"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "B. Redfors"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "E. Omerovic"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7hxhymqxc5k7h.bib",
  "cited_by": 0,
  "doi": "10.1186/s12872-026-06889-0",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13729366/",
  "id": "7hxhymqxc5k7h",
  "issns": [
    "1471-2261"
  ],
  "landing_url": "https://doi.org/10.1186/s12872-026-06889-0",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
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      "heading",
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      "2705|Takotsubo Cardiomyopathy and Associated Phenomena"
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  "openalex": "W7224269631",
  "pdf_url": null,
  "pmcid": "PMC13729366",
  "pmid": "42977912",
  "published": "2026-10-29",
  "publisher": "BMC",
  "ris": "https://research.draconitic.com/paper/7hxhymqxc5k7h.ris",
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    {
      "first_seen": "2026-11-07T12:22:08Z",
      "native_id": "PMC13729366",
      "source": "pmc",
      "url": "https://doi.org/10.1186/s12872-026-06889-0"
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  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2705|Takotsubo Cardiomyopathy and Associated Phenomena",
      "subfield": "cardiovascular"
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  ],
  "title": "Impact of the COVID-19 pandemic on the incidence and mortality of Takotsubo syndrome in Sweden, a report from the SWEDEHEART registry",
  "title_text": "Impact of the COVID-19 pandemic on the incidence and mortality of Takotsubo syndrome in Sweden, a report from the SWEDEHEART registry",
  "type": "peer-reviewed",
  "updated_at": "2026-11-07T12:22:08Z",
  "url": "https://research.draconitic.com/paper/7hxhymqxc5k7h",
  "venue": "BMC Cardiovascular Disorders",
  "versions": []
}