Direct comparison of high-sensitivity cardiac troponin T and I in the early differentiation of type 1 vs. type 2 myocardial infarction

AIMS: To directly compare the diagnostic accuracy of high-sensitivity cardiac troponin (hs-cTn) T vs. hs-cTnI in the early non-invasive differentiation of Type 1 myocardial infarction (T1MI) due to plaque rupture and atherothrombosis from Type 2 myocardial infarction (T2MI) due to supply-demand mismatch.

METHODS AND RESULTS: In a prospective multicentre diagnostic study, two independent cardiologists centrally adjudicated the final diagnosis of T1MI vs. T2MI according to the fourth universal definition of myocardial infarction (MI), using all available clinical information including cardiac imaging in patients presenting with acute chest pain. Diagnostic accuracy was quantified by the area under the receiver operating characteristics curve (AUC). The most extensively validated hs-cTnT-Elecsys and hs-cTnI-Architect assays were measured at presentation, 1 h, and 2 h. Among 5887 patients, 1106 (19%) had a final diagnosis of MI, including 860 (78%) T1MI and 246 (22%) T2MI. The AUC of hs-cTnT-Elecsys to differentiate T1MI from T2MI was moderate and comparable to that provided by hs-cTnI-Architect: hs-cTnT-Elecsys AUC-presentation 0.67 [95% confidence interval (CI) 0.64-0.71], AUC-1 h 0.70 (95% CI 0.66-0.74), and AUC-2 h 0.71 (95% CI 0.66-0.75) vs. hs-cTnI-Architect AUC-presentation 0.71 (95% CI 0.67-0.74), AUC-1 h 0.72 (95% CI 0.68-0.76), and AUC-2 h 0.74 (95% CI 0.69-0.78), all P = not significant (NS). Similarly, the AUC of absolute changes was moderate and comparable for hs-cTnT-Elecsys and hs-cTnI-Architect (all P = NS). Cut-off concentrations achieving at least 90% specificity for the differentiation of T1MI vs. T2MI were >114 ng/L for hs-cTnT-Elecsys [odds ratio (OR) 4.2, 95% CI 2.7-6.6] and >371 ng/L for hs-cTnI-Architect (OR 4.0, 95% CI 2.6-6.2).

CONCLUSION: hs-cTnT-Elecsys and hs-cTnI-Architect provided comparable, albeit only moderate, diagnostic accuracy for the early differentiation of T1MI vs. T2MI.

CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov number, NCT00470587, https://clinicaltrials.gov/ct2/show/NCT00470587.