Which high-sensitivity troponin variable best characterizes infarct size and microvascular obstruction?

Abstract

Background: The link between hs-Tn and infarct size has already been proved in several articles. However few is known about the kinetic of the troponin and its link to the infarct characteristics, likewise MVO. Our primary objective was to study which hs-Tn characterizes the best infarction.

Methods and results: We identified 29 consecutive STEMI patients to study. The kinetics of hs-TnT (Roche) and two different TnIs (hs-TnI from Abbott, s-TnI from Siemens) were evaluated for all patients. Area under curves (AUC), first peak (FP) and second peak (SP), for hs-TnT, were compared to IS and MVO size using contrast-enhanced cardiac magnetic resonance. For IS, statistically SP of hs-TnT presented the best correlation compared to other peak values [r=0.9 vs. 0.73 for FP hs-TnT; vs. 0.69 for hs-TnI; vs. 0.57 for s-TnI; respectively P<0.01, P<0.01, P<0.01]. For MVO size, statistically SP of hs-TnT presented the best correlation compared to other peak values [r=0.84 vs. 0.75 for FP hs-TnT; vs. 0.72 for hs-TnI; vs. 0.62 for s-TnI; respectively P=0.01, P<0.01, P<0.01]. The best AUC were archived by the hs-TnT (AUC=0.95) but there were no statistical differences when compared to other hs-Tn AUC.

Conclusion: The SP of hs-TnT had the greatest level of correlation and therefore seems to be the best biological parameter to evaluate and characterize infarct size.

Keywords: Acute myocardial infarction; Ce-CMR; High-sensitivity troponin; IRM cardiaque; Infarct characterization; Infarctus du myocarde aigu; Microvascular obstruction; Obstruction micro-vasculaire; Taille de nécrose; Troponine sensible.