Lit Matters 3: Is A Single hs-cTnT Enough to Rule Out ACS?

A single high-sensitivity troponin T can identify a very low-risk acute coronary syndrome cohort when paired with a non-ischemic ECG. For ED chest pain evaluation, the key controversy is whether one undetectable hs-cTnT is enough to safely avoid serial testing in selected patients.

Single hs-cTnT for ACS Rule-Out

• Guideline and assay tension: European pathways use the limit of detection at 5 ng/L, while FDA reporting and US practice center on the limit of quantitation at 6 ng/L for Roche hs-cTnT.
• Core clinical question: The practical test was whether one hs-cTnT below 6 ng/L can safely identify low-risk ED patients with possible ACS, and whether a non-ischemic ECG improves that rule-out.
• Large multicenter cohort: Across 85,610 Mayo Clinic ED patients, about 29% had an initial hs-cTnT below 6 ng/L, giving this single-sample strategy a substantial real-world sample.
• Chest pain subgroup signal: Performance looked strongest in patients presenting with chest pain, where an initial hs-cTnT below 6 ng/L was associated with only 0.2% acute MI at the index visit.
• Non-ischemic ECG pairing: Adding a non-ischemic ECG to hs-cTnT below 6 ng/L produced a 100% negative predictive value for index MI in the studied subgroup, with one 30-day event among 610 patients. We get into where that combination may be most defensible in the episode.
• Serial troponin uncertainty: A second troponin may add reassurance, but this study did not clearly show improved patient-oriented outcomes from serial testing once the first hs-cTnT and ECG were already low risk.