Importance: High-sensitivity cardiac troponin T and I assays are considered equivalent for the diagnosis of myocardial infarction. However, the impact of transitioning from an assay measuring cardiac troponin I to one measuring cardiac troponin T on patient care and clinical outcomes is unknown.
Objective: To evaluate the impact of transitioning from a high-sensitivity assay measuring cardiac troponin I to one measuring cardiac troponin T on the care and outcomes of consecutive patients with suspected acute coronary syndrome.
Design, Setting, and Participants: This was a prospective, multicenter, interrupted time-series study conducted at 3 acute care centers. Consecutive patients presenting with suspected acute coronary syndrome to an acute care hospital were identified between October 2020 and October 2022.
Interventions: All sites changed from an assay measuring cardiac troponin I to one measuring cardiac troponin T in October 2021.
Main Outcomes and Measures: The primary outcome was hospital admission.
Results: Among 25 849 patients, 13 146 (median [IQR] age, 60 [47-73] years; 6961 male [53%]) and 12 703 (median [IQR] age, 60 [47-73] years; 6825 male [54%]) presented before and after the transition to cardiac troponin T, respectively. The proportion of patients with myocardial injury increased from 21% (2800 of 13 146 patients) to 38% (4781 of 12 703 patients), and patients were more likely to be admitted to the hospital after the transition (odds ratio [OR], 2.24; 95% CI, 1.81-2.77; both P < .001). A 6-fold increase in serial testing was observed in patients undergoing a measure of cardiac troponin T compared with cardiac troponin I (OR, 6.03; 95% CI, 4.85-7.49; P < .001). Subsequent myocardial infarction, heart failure, or cardiovascular death at 1 year was comparable before and after the transition (OR, 0.83; 95% CI, 0.48-1.41; P = .49).
Conclusions and Relevance: The transition from a high-sensitivity assay measuring cardiac troponin I to one measuring cardiac troponin T was associated with increased identification of myocardial injury, serial troponin measurements, and hospital admissions without evidence of improved cardiovascular outcomes at 1 year.
Trial Registration: ClinicalTrials.gov Identifier: NCT05748691
