Prevalence and potential mechanisms leading to persistent elevation of high sensitive troponin T in patients 6 month after acute myocardial infarction
© Neizel et al; licensee BioMed Central Ltd. 2009
Published: 28 January 2009
Persistent minor troponin elevation in patients with coronary heart disease is associated with adverse outcome and prognosis. However, the mechanism is not yet clearly understood.
Our objectives were to examine the prevalence and range of cardiac troponin T (cTnT) in stable patients six months after acute myocardial infarction (AMI) using a new high sensitive cTnT assay and to investigate the association of persistent minor cTnT-elevation to clinical variables, NT-pro BNP and cardiac MR-findings.
cTnT was measured in 98 patients at 6 months after AMI. Patients were investigated in a clinical 1.5 Tesla whole body MR-scanner (Achieva, Philips, Best, the Netherlands) 3 ± 1 days after successful mechanical reperfusion of the infarct related vessel and at a follow-up of 6 ± 1 month using a 5-element phased array cardiac synergy coil.
Assessment of resting left ventricular function was determined by cine images using a steady-state-free precession sequence in 10–12 8 mm-thick slices covering the whole left ventricle from base to apex as well as long axis 2,-3 and 4-chamber views.
Ten minutes after gadolinium contrast injection (0.2 mmol/kg body weight of Gadolinium-DTPA (Magnevist®, Bayer, Germany)) late enhancement-imaging was performed using an inversion-recovery gradient-echo technique triggered to end-diastole. Data analysis of MRI-images was performed using a usual Philips work station.
cTnT was measured using a precommercial assay by electrochemiluminescence methods (Roche Diagnostics, Mannheim, Germany.
Minor cTnT-concentrations were detectable in 90% of the entire cohort, of whom 16% had cTnT-values above the 99th percentile (> 12 ng/L). These patients were also significantly older, suffered more frequently from hypertension, had a higher New York Heart Association class and received more often diuretics at follow-up. Patients with cTnT-elevation had a more impaired left ventricular ejection fraction (p = 0.02) but did not have an increased infarct size (p = 0.73).
Elevated minor cTnT levels are frequently detectable in patients 6 month after AMI. Increased cTnT-level were associated with clinical parameter for heart failure, impaired ejection fraction and higher NT-pro-BNP levels suggesting that myocardial dysfunction leads to persistent cTnT-elevation.
This article is published under license to BioMed Central Ltd.