Late microvascular obstruction after acute myocardial infarction: Relation with cardiac and inflammatory markers

Abstract Objectives We sought to assess the relation of late microvascular obstruction (l-MVO) size as quantified by cardiac magnetic resonance (CMR) imaging with cardiac and inflammatory marker concentrations after acute myocardial infarction (AMI). Methods CMR was performed in 118 consecutive patients within 8 days after successful interventional reperfused first acute ST-elevation AMI. Infarct volumes and l-MVO sizes were calculated from late enhancement (LE) sequences and functional parameters were determined from short-axis cine MR sequences. Creatine kinase (CK) and cardiac troponin T (cTnT), high-sensitivity C-reactive protein (hs-CRP) as well as lactate dehydrogenase (LD) concentrations were determined serially from day 1 to day 4 after symptom onset. Results L-MVO was detected in 66/118 patients (55.9%) and comprised 18.2 ± 10% of infarct size and 4.7 ± 3% of left ventricle myocardial mass. Each single-point, peak and cumulative release concentration of cTnT (r = 0.44 to 0.73, p < 0.0001), CK (r = 0.21 to 0.76, p < 0.0001), LD (r = 0.36 to 0.82, all p < 0.0001) as well as hs-CRP single-point values as assessed from day 1 to day 4 and its peak and cumulative release concentrations (r = 0.24 to 0.49, p < 0.003) significantly correlated with l-MVO size. Receiver operating curve (ROC) analysis indicated a cut-off value of 4.7 μg/l cTnT to best identify the presence of l-MVO (area under the curve (AUC) 0.904; 95% CI: 0.85–0.95; p < 0.0001). Conclusion L-MVO sizes significantly correlate with cardiac and inflammatory marker concentrations as determined early after AMI. cTnT concentration of > 4.7 μg/l could help to identify patients in whom l-MVO is present.