Direct Comparison of the 0/1h- and 0/2h-Algorithms in Patients With Prior Coronary Artery Bypass Grafting.

BACKGROUND: The European Society of Cardiology (ESC) 0/1h-high-sensitivity cardiac troponin (hs-cTn)T/I-algorithms have lower efficacy in patients with prior coronary artery bypass grafting. We hypothesized that in these high-risk patients, the longer time to the second blood draw within the ESC 0/2h-hs-cTn-algorithms would increase efficacy, defined as the proportion of patients triaged to rule-in/out of myocardial infarction, versus the ESC-0/1h-hs-cTn-algorithms. METHODS: In a prospective international multicenter diagnostic study including patients presenting to the emergency department with acute chest discomfort, final diagnoses were centrally adjudicated according to the Universal Definition of Myocardial Infarction. Safety and efficacy of the guideline-recommended ESC 0/1h- and 0/2h-hs-cTn-algorithms using assay-specific use-optimized cut-offs were directly compared in patients with prior coronary artery bypass grafting. Findings were externally validated in an independent prospective US multicenter study. RESULTS: Among 356 patients (median [interquartile range] age 73 [64-80] years, prevalence of non-ST-segment-elevation myocardial infarction [NSTEMI]: 31% [n=112]), sensitivity for rule-out of NSTEMI was high for the ESC 0/1h- and 0/2h-hs-cTnT-Elecsys-algorithms (0/1h: 100% [95% CI 96.7-100]; 0/2h: Sensitivity: 99.1% [95% CI 95.1-99.8]). Specificity for rule-in of NSTEMI was also high (0/1h: 97.1% [95% CI 94.2-98.6]; 0/2h 98.4% [95% CI 95.9-99.4]). Efficacy was 50.6% for 0/1h and 58.4% for 0/2h (difference: 7.9% [95% CI 4.2-11.5]). Findings with higher efficacy for 0/2h versus 0/1h were confirmed using hs-cTnI-Architect (difference in efficacy 3.1% [95% CI 0.1-6.1]) and using hs-cTnI-Atellica in the external validation cohort (n=178; difference in efficacy 9% [95% CI 4.5-13.5]). CONCLUSIONS: The ESC 0/2h-hs-cTn-algorithms have higher efficacy and comparable safety versus the ESC 0/1h-hs-cTn-algorithms in patients with prior coronary artery bypass grafting. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique Identifier: NCT00470587.