{
  "abstract": "BackgroundDelayed diagnosis of immunoglobulin light-chain cardiac amyloidosis (AL-CA) worsens prognosis, partly because AL-CA and wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) are difficult to distinguish at the initial cardiology visit. We developed and validated a practical score to triage AL-CA from ATTRwt-CA.\n\nMethodsWe retrospectively analyzed 541 consecutive patients with cardiac amyloidosis (91 AL-CA, 450 ATTRwt-CA) at our institutions amyloidosis center, randomly divided into derivation (n=378) and validation (n=163) cohorts. Candidate first-visit variables underwent LASSO selection after multiple imputation, with estimates pooled by Rubins rules. Performance was assessed by bootstrap validation, calibration, and decision curve analysis. The model was converted into a simplified point-based score.\n\nResultsSeven variables were retained: age, absence of atrial fibrillation, absence of carpal tunnel syndrome, low serum albumin, proteinuria ([≥]1+), low voltage, and thinner left ventricular posterior wall thickness. Areas under the curve (AUC) were 0.97 in the derivation cohort and 0.99 in the validation cohort; the bootstrap optimism-corrected AUC was 0.96. The model provided net benefit across threshold probabilities of 0.01- 0.50. Risk tiering categorized the validation cohort into low (0-5 points; AL-CA 0%), intermediate (6-9 points; 26%), and high (10-13 points; 95%) probability groups. Discrimination remained high for AL-CA versus monoclonal protein-positive ATTRwt-CA at a cutoff of [≥]8 points (AUC 0.90). Adding this score to monoclonal protein testing significantly improved diagnostic performance compared with monoclonal protein testing alone.\n\nConclusionsThis simple first-visit score may help cardiologists rapidly triage suspected AL-CA and prioritize urgent hematology referral and subtype-specific confirmatory testing.\n\nClinical Perspective1) What Is New?O_LIA 7-variable score using age, history of atrial fibrillation and carpal tunnel syndrome, serum albumin, dipstick proteinuria, low QRS voltage, and left ventricular posterior wall thickness distinguished AL-CA from ATTRwt-CA using information available at the first cardiology visit. C_LIO_LIThe score retained high discrimination in the challenging subgroup comprising patients with AL-CA or monoclonal protein-positive ATTRwt-CA. C_LI\n\n2) What Are the Clinical Implications?O_LIThe score may complement--not replace--standard monoclonal protein testing and definitive amyloid typing by helping prioritize the urgency of hematology assessment and subtype-specific confirmatory evaluation. C_LI",
  "abstract_shown": true,
  "affiliations": [
    "Kumamoto Daigaku"
  ],
  "article_type": "PUBLISHAHEADOFPRINT",
  "arxiv": null,
  "author_total": 15,
  "authors": [
    {
      "name": "Y. Matsumoto"
    },
    {
      "affs": [
        0
      ],
      "name": "Y. Izumiya"
    },
    {
      "name": "Y. Kawano"
    },
    {
      "name": "N. Kuyama"
    },
    {
      "name": "K. Morikawa"
    },
    {
      "name": "A. Tabira"
    },
    {
      "name": "M. Yamamoto"
    },
    {
      "name": "K. Hirakawa"
    },
    {
      "name": "M. Ishii"
    },
    {
      "name": "S. Hanatani"
    },
    {
      "name": "Y. Matsuzawa"
    },
    {
      "name": "H. Usuku"
    },
    {
      "name": "E. Yamamoto"
    },
    {
      "name": "H. Soejima"
    },
    {
      "name": "K. Tsujita"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8zf1d1kctx0k4.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.09.10.26362801",
  "fulltext_url": "https://www.medrxiv.org/content/10.64898/2026.09.10.26362801v1.full",
  "id": "8zf1d1kctx0k4",
  "issns": [],
  "landing_url": "https://www.medrxiv.org/content/10.64898/2026.09.10.26362801v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "medrxiv",
      "cardiovascular medicine"
    ],
    [
      "openalex",
      "1312|Amyloidosis: Diagnosis, Treatment, Outcomes"
    ]
  ],
  "openalex": "W7212428332",
  "pdf_url": "https://www.medrxiv.org/content/10.64898/2026.09.10.26362801v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-10",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/8zf1d1kctx0k4.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:28Z",
      "native_id": "10.64898/2026.09.10.26362801",
      "source": "medrxiv",
      "url": "https://www.medrxiv.org/content/10.64898/2026.09.10.26362801v1"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "medrxiv:cardiovascular medicine",
      "subfield": "cardiovascular"
    }
  ],
  "title": "A First-Visit Clinical Score to Distinguish Immunoglobulin Light-Chain from Wild-Type Transthyretin Cardiac Amyloidosis: Derivation and Internal Validation",
  "title_text": "A First-Visit Clinical Score to Distinguish Immunoglobulin Light-Chain from Wild-Type Transthyretin Cardiac Amyloidosis: Derivation and Internal Validation",
  "type": "preprint",
  "updated_at": "2026-10-30T12:18:28Z",
  "url": "https://research.draconitic.com/paper/8zf1d1kctx0k4",
  "venue": "medRxiv",
  "versions": []
}