Measurement of troponin I 48 h after admission as a tool to rule out impaired left ventricular function in patients with a first myocardial infarction.
Few studies have evaluated cardiac troponin I (cTnI) as a marker for infarct size and left ventricular (LV) dysfunction. Here we investigated the ability of a single-point cTnI, measured with a second-generation assay (Access AccuTnI), to estimate infarct size and assess LV function in patients with a first myocardial infarction (AMI). cTnI measurements were performed 12 and 48 h after admission in 63 consecutive AMI patients. LV function was evaluated by gated single-photon emission computed tomography (SPECT) and infarct size was estimated by CK-MB peak and SPECT myocardial perfusion. LV function and infarct size were evaluated by SPECT before hospital discharge. SPECT was also repeated 3 months later. Significant correlations (p<0.001) were found between cTnI at 12 and 48 h and both the peak CK-MB (r=0.61 and r=0.82, respectively) and the perfusion defect size at SPECT (r=0.55 and r=0.61, respectively). cTnI at 12 and 48 h were inversely related (p<0.001) to LV ejection fraction (LVEF) assessed both early (r=-0.45 and r=-0.57, respectively) and 3 months after AMI (r=-0.51 and r=-0.69, respectively). cTnI >14.8 microg/L at 48 h predicted an LVEF <40% at 3 months with a sensitivity of 100% [95% confidence interval (CI) 73.5-100%], specificity of 65% (CI 49-79%), and a negative predictive value of 100%. Our findings demonstrate that a single cTnI measurement 48 h after admission is useful for ruling out impaired LV function in a routine clinical setting.
Panteghini
Mauro
M
Dipartimento di Scienze Cliniche Luigi Sacco, Facoltà di Medicina e Chirurgia-Polo di Vialba, Università degli Studi di Milano, Milan, Italy. mauro.panteghini@unimi.it
Bonetti
Graziella
G
Pagani
Franca
F
Stefini
Francesca
F
Giubbini
Raffaele
R
Cuccia
Claudio
C
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood; D052279:Creatine Kinase, MB Form; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000000981:diagnostic imaging; D011446:Prospective Studies; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D019210:Troponin I / Q000097:blood*; D018487:Ventricular Dysfunction, Left / Q000097:blood* / Q000175:diagnosis* / Q000000981:diagnostic imaging; D016277:Ventricular Function, Left / Q000502:physiology
D015415:Biomarkers; D007527:Isoenzymes; D019210:Troponin I; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form