High-sensitivity troponin (hs-Tn)

High-sensitivity troponin (hs-Tn) assays measure the cardiac isoforms troponin I (hs-TnI) or troponin T (hs-TnT) at concentrations about 10-fold lower than conventional assays, with analytical coefficient of variation ≤10% at the 99th-percentile reference limit. This sensitivity enables detection of the small troponin leaks that occur with myocardial injury from acute MI, myocarditis, takotsubo syndrome, and demand ischemia, as well as low-grade chronic cardiomyocyte injury. Beyond acute chest-pain rule-out, chronically elevated hs-Tn in the population predicts incident heart failure, atrial fibrillation, and cardiovascular and all-cause mortality independently of established risk factors, making it an emerging biomarker of subclinical cardiac aging and injury. Values must always be interpreted in clinical context, as non-cardiac causes (e.g., renal failure, sepsis, pulmonary embolism) can also elevate troponin.