High-sensitivity troponin in the evaluation of patients with suspected acute coronary syndrome: a stepped-wedge, cluster-randomized controlled trial
Clinical question: Does the introduction of a high-sensitivity cardiac troponin I (hs-cTnI) assay with a sex-specific 99th centile diagnostic threshold reduce subsequent myocardial infarction or cardiovascular death at 12 months in patients with suspected acute coronary syndrome?
What is known: High-sensitivity cardiac troponin assays permit use of lower thresholds for the diagnosis of myocardial infarction, but whether this improves clinical outcomes is unknown.
Methods:In this stepped-wedge, cluster-randomized controlled trial across ten secondary or tertiary care hospitals in Scotland, the authors evaluated the implementation of an hs-cTnI assay in consecutive patients who had been admitted to the hospitals’ emergency departments with suspected acute coronary syndrome.The study consisted of two phases; a validation and an implementation phase. The intervention arm was hs-troponin and the control arm was conventional troponin.
Results/Implications: The authors enrolled 48 282 consecutive patients, of whom 10 360 (21%) patients had cTnI concentrations greater than those of the 99th centile of the normal range of values, who were identified by the contemporary assay or the high-sensitivity assay. The high-sensitivity assay reclassified 1771 (17%) of 10 360 patients with myocardial injury or infarction who were not identified by the contemporary assay. In those reclassified, subsequent myocardial infarction or cardiovascular death within 1 year occurred in 105 (15%) of 720 patients in the validation phase and 131 (12%) of 1051 patients in the implementation phase (adjusted odds ratio for implementation vs validation phase 1·10, 95% CI 0·75 to 1·61; p=0·620).
Bottom-line: The use of high-sensitivity troponin lowers the diagnostic threshold for myocardial infarction in patients with suspected ACS, but was not associated with a lower subsequent incidence of myocardial infarction or cardiovascular death at 1 year.