{
  "abstract": "Background: SMuRFless patients with acute coronary syndrome lack traditional modifiable cardiovascular risk factors, however, concerns remain regarding their potentially poorer clinical outcomes.\n\nMethodology: This PRISMA-compliant meta-analysis was registered with PROSPERO (CRD420251021614). A single-arm meta-analysis was conducted to estimate the proportion of SMuRFless patients, while a random-effects frequentist meta-analysis compared SMuRFless vs. SMuRF patients. Statistical analyses were performed using R (version 2025.05.0 + 496; Posit).\n\nResults: Thirty studies comprising 2,650,310 patients were included, of whom 356,716 (13.5%) were SMuRFless. The pooled proportion of SMuRFless patients was 0.11 (95% CI, 0.09–0.14), with substantial heterogeneity ( I ² = 100.0%, τ ² = 0.6932). Regarding coronary anatomy, SMuRFless patients had less multivessel disease, LCX involvement, and combined RCA/LCX involvement, but more frequent LAD and LMCA involvement than patients with SMuRFs. Despite a lower burden of comorbidities, SMuRFless status was associated with higher in-hospital mortality (RR, 1.68, 95% CI, 1.41–2.01), 30-day mortality (RR, 2.06, 95% CI, 1.16–3.63), cardiogenic shock (RR, 1.46, 95% CI, 1.24–1.70), and cardiac death (RR, 1.61, 95% CI, 1.03–2.50), whereas 1-year, 2-year, 3-year, and 5-year mortality did not differ significantly between groups. Rates of major bleeding, stroke, recurrent myocardial infarction, PCI, and antiplatelet therapy were comparable; however, SMuRFless patients were less likely to undergo CABG (RR, 0.78, 95% CI, 0.61–0.98) or receive ACE inhibitors/ARBs at discharge (RR, 0.87, 95% CI, 0.79–0.96).\n\nConclusion: SMuRFless patients represent a substantial minority of ACS patients and, despite fewer traditional risk factors, are characterized by distinct coronary anatomy and higher observed short-term adverse event rates.\n\nSystematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251021614 , identifier CRD420251021614.",
  "abstract_shown": true,
  "affiliations": [
    "College of Medicine, Alfaisal University",
    "Department of Medicine, Nassau University Medical Center",
    "Department of Cardiology, Sheikh Zayed Medical College",
    "Department of Medicine, Allama Iqbal Medical College",
    "Department of Medicine, Khawaja Muhammad Safdar Medical College",
    "Department of Medicine, Pakistan Institute of Medical Sciences",
    "Department of Cardiology, Ch Pervaiz Elahi Institute of Cardiology",
    "Department of Medicine, University Medical and Dental College",
    "Department of Medicine, The Valley Health System Consortium"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 13,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Sadia Qazi"
    },
    {
      "affs": [
        1
      ],
      "name": "Mohammad Hamza Bin Abdul Malik"
    },
    {
      "affs": [
        2
      ],
      "name": "Muhammad Arham"
    },
    {
      "affs": [
        2
      ],
      "name": "Anfal Hamza"
    },
    {
      "affs": [
        2
      ],
      "name": "Muhammad Awais Bin Abdul Malik"
    },
    {
      "affs": [
        3
      ],
      "name": "Faseeh Haider"
    },
    {
      "affs": [
        4
      ],
      "name": "Sufyan Shahid"
    },
    {
      "affs": [
        5
      ],
      "name": "Mishal Khan"
    },
    {
      "affs": [
        3
      ],
      "name": "Minahil Iqbal"
    },
    {
      "affs": [
        2
      ],
      "name": "Aleena Sharif"
    },
    {
      "affs": [
        6
      ],
      "name": "Tahira Nazir"
    },
    {
      "affs": [
        7
      ],
      "name": "Ayesha Ihsan"
    },
    {
      "affs": [
        8
      ],
      "name": "Ali Haq"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1mm8zn0m9bmyj.bib",
  "cited_by": 0,
  "doi": "10.3389/fcvm.2026.1931296",
  "fulltext_url": null,
  "id": "1mm8zn0m9bmyj",
  "issns": [
    "2297-055X"
  ],
  "landing_url": "https://www.frontiersin.org/articles/10.3389/fcvm.2026.1931296/full",
  "language": null,
  "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": [],
  "openalex": null,
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-29",
  "publisher": "Frontiers Media SA",
  "ris": "https://research.draconitic.com/paper/1mm8zn0m9bmyj.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:10Z",
      "native_id": "10.3389/fcvm.2026.1931296",
      "source": "crossref",
      "url": "https://www.frontiersin.org/articles/10.3389/fcvm.2026.1931296/full"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "issn:2297-055X",
      "subfield": "cardiovascular"
    }
  ],
  "title": "An updated meta-analysis of clinical outcomes, interventions, and treatment approaches in SMuRF vs. SMuRFless: evidence from 2.6 million ACS patients",
  "title_text": "An updated meta-analysis of clinical outcomes, interventions, and treatment approaches in SMuRF vs. SMuRFless: evidence from 2.6 million ACS patients",
  "type": "peer-reviewed",
  "updated_at": "2026-10-31T00:21:07Z",
  "url": "https://research.draconitic.com/paper/1mm8zn0m9bmyj",
  "venue": "Frontiers in Cardiovascular Medicine",
  "versions": []
}