0/1-Hour Algorithms Using High-Sensitivity Cardiac Troponin I in Patients With Prior Coronary Artery Bypass Grafting

Objectives: A pilot study suggested that high-sensitivity cardiac troponin T/I (hs-cTnT/I) has a lower diagnostic accuracy in patients with prior coronary artery bypass grafting (CABG). It is unknown whether this affects the performance of the three recently developed hs-cTnI 0/1-hour algorithms.

Methods: In a secondary analysis of a prospective international multicenter study enrolling adult patients presenting to the emergency department with symptoms suggestive of myocardial infarction (MI), we assessed the performance of the hs-cTnI 0/1-hour algorithms using hs-cTnI-Architect, hs-cTnI-access, and hs-cTnI-centaur assays in patients with versus without prior CABG. The final diagnosis was adjudicated by two independent cardiologists applying the fourth universal definition of acute myocardial infarction (AMI) using all the medical records available, cardiac imaging data, as well as study-specific assessments including serial measurements of hs-cTnI-architect.

Results: In patients with a history of CABG, the ESC hs-cTnI-architect 0/1-hour algorithm maintained a very high–negative predictive value (NPV) of 100% (95% confidence interval [CI]: 93.4–100) and a high–positive predictive value (PPV) of 78% (95% CI: 67.9–85.6), but had a lower efficacy with more patients remaining in the observe zone (46 vs. 26% compared to 2,643 patients without prior CABG; p < 0.001).

These results were internally validated in patients with available 0/1-hour blood concentrations of hs-cTnI-access (n = 1,385) and hs-cTnI-centaur (n = 2,124). Among 105 patients with a history of CABG, the hs-cTnI-access 0/1-hour algorithm maintained a very high NPV of 100% (95%CI: 83.9–100) and a high PPV of 82.8% (95%CI: 65.5–92.4). Efficacy was lower with more patients remaining in the observe zone (53 vs. 26% compared to 1,280 patients without prior CABG; p < 0.001).

Among 180 patients with prior CABG, the hs-cTnI-centaur 0/1-hour algorithm had a NPV of 97.4% (95%CI: 86.8–99.5) and a PPV of 82.6% (95%CI: 69.3–90.9). Again, efficacy was lower with more patients remaining in the observe zone (53 vs. 34% compared to 1,944 patients without prior CABG; p < 0.001).

Conclusion: All three established hs-cTnI 0/1h-algorithms had lower efficacy in patients with prior CABG, but still provide an excellent performance for safely ruling out and accurately ruling in MI in this vulnerable patient cohort.