A narrative review in JACC, published on 28 October 2026, argues that high-sensitivity troponin assays have solved detection and created a classification problem. Raised values are common across cardiac and systemic illness, and misclassification runs both ways.
Non-ischaemic injury in sepsis, kidney disease, tachyarrhythmia or pulmonary embolism is often labelled as type 2 myocardial infarction, inflating MI diagnoses. At the other end, chronic myocardial injury — a stable raised troponin without a rise-and-fall pattern — is often dismissed once infarction is excluded, although the review notes its risk of later MI or cardiovascular death approaches that of type 1 MI.
The authors set out four domains for interpretation: assay-specific and sex-specific thresholds and interference; the strengths and limits of the 0/1-hour and 0/2-hour pathways; the distinction between injury, necrosis and infarction under the universal definition; and the conditions in which a raised troponin is expected. Their message is that no algorithm removes the need for this judgement.
- Use the sex-specific upper reference limit for the assay your laboratory runs.
- Look for a dynamic rise or fall before calling a raised troponin acute injury.
- Label stable raised troponin as chronic myocardial injury rather than 'troponin leak'.
- Arrange cardiovascular risk assessment for chronic injury instead of discharging it as non-cardiac.
- Reserve 'type 2 MI' for injury with clear evidence of supply-demand ischaemia, not any raised value in an ill patient.
Why it matters
A chronic troponin rise that is dismissed after MI is excluded marks a patient whose risk is easy to miss.
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A narrative review with expert guidance; it offers no new trial data.
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