Unrecognized myocardial infarctions detected by cardiac magnetic resonance imaging are associated with cardiac troponin I levels

Abstract

Background: Both unrecognized myocardial infarction (UMI) and elevated levels of biomarkers are common in patients with stable coronary artery disease (CAD). The objective of this study was to determine the association between levels of cardiac biomarkers, UMI and extent of CAD in patients with stable CAD.

Methods: A total of 235 patients (median age: 65years; 34% women) with stable CAD without previously known myocardial infarction were examined with late gadolinium enhancement cardiovascular magnetic resonance imaging and coronary angiography. Blood samples were drawn at enrolment and high sensitivity cardiac troponin I (cTnI), NT-proBNP and Galectin-3 were analyzed.

Results: UMI was detected in 58 patients (25%). The median levels of cTnI, NT-proBNP and Galectin-3 were significantly higher in patients with UMI compared to those without, (p<0.001, p=0.006 and p=0.033, respectively). After adjustment for cardiovascular risk factors, left ventricular ejection fraction and renal function, cTnI remained independently associated with the presence of UMI (p=0.031) and the extent of CAD (p=0.047). Neither NT-proBNP, nor Galectin-3, was independently associated with UMI or extent of CAD.

Conclusions: The independent association between levels of cTnI and UMI indicates a common pathophysiological pathway for the cTnI elevation and development of UMI.

Clinical trial registration: ClinicalTrials.gov (NCT01257282).

Keywords: Cardiac magnetic resonance imaging; Cardiac troponin; Coronary artery disease; NT-proBNP; Unrecognized myocardial infarction.