{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,19]],"date-time":"2026-10-19T21:36:02Z","timestamp":1792445762137,"version":"4.5.0"},"reference-count":15,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T00:00:00Z","timestamp":1784764800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Cardiovasc. Med."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>High-sensitivity cardiac troponin T (hs-cTnT) is widely used as a gold-standard marker of myocardial injury, yet non-ischemic elevations can occur in idiopathic inflammatory myopathies (IIM), creating a significant diagnostic pitfall. In contrast, high-sensitivity cardiac troponin I (hs-cTnI) generally retains strict cardiac specificity.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Case report<\/jats:title>\n                    <jats:p>A 79-year-old female presented with progressive fatigue and elevated cardiac enzymes. Admission hs-cTnT was markedly elevated at 521\u2005ng\/L (reference 0\u201314\u2005ng\/L), and she was initially suspected of having a non-ST elevation myocardial infarction (NSTEMI) and underwent emergency coronary angiography, which revealed non-obstructive coronary artery disease. Polyethylene glycol (PEG) precipitation demonstrated a recovery rate exceeding 80%, excluding macromolecular complex interference, while follow-up hs-cTnT testing at an external hospital confirmed the elevation. However, hs-cTnI measured on both the Abbott and Yhlo platforms remained within normal limits. This hs-cTnT(+)\/hs-cTnI(\u2212) discrepancy, combined with electromyography (myogenic damage), muscle MRI, and a normal echocardiogram, established the final diagnosis of polymyositis (PM).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Regenerating skeletal muscle fibers can re-express embryonic cTnT isoforms, producing a true circulating cTnT elevation of skeletal muscle origin that mimics myocardial injury. PEG precipitation confirmed authentic monomeric cTnT antigen rather than an analytical artifact, redirecting the diagnostic focus. Concurrent hs-cTnI assessment is a critical strategy for distinguishing skeletal muscle-derived cTnT from true myocardial injury, thereby preventing misdiagnosis and unnecessary interventions in patients with inflammatory myopathies.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fcvm.2026.1854699","type":"journal-article","created":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T13:46:01Z","timestamp":1784814361000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Case Report: Discordant high-sensitivity cardiac troponin T elevation in polymyositis: a diagnostic pitfall"],"prefix":"10.3389","volume":"13","author":[{"given":"Shuanglin","family":"Zheng","sequence":"first","affiliation":[{"name":"Department of Clinical Laboratory, Xiamen Cardiovascular Hospital, Xiamen University","place":["Xiamen, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Huabin","family":"Xie","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory, Xiamen Cardiovascular Hospital, Xiamen University","place":["Xiamen, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,7,23]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"959","DOI":"10.1016\/S0735-1097(00)00804-4","article-title":"Myocardial infarction redefined\u2013a consensus document of the joint European society of cardiology\/American College of Cardiology committee for the redefinition of myocardial infarction","volume":"36","author":"Antman","year":"2000","journal-title":"J Am Coll Cardiol"},{"key":"B2","doi-asserted-by":"publisher","first-page":"9713326","DOI":"10.1155\/2022\/9713326","article-title":"High-sensitivity troponin: a review on characteristics, assessment, and clinical 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