Cardiac troponin I and Q-wave perioperative myocardial infarction after coronary artery bypass surgery.
OBJECTIVE
To monitor cardiac troponin I (cTnI), a newly developed biochemical index for cardiac damage, in patients during and after coronary artery bypass surgery (CABS) to determine whether the measurement of the serum levels of this marker could be of value in formulating an early diagnosis of Q-wave perioperative myocardial infarction (PMI).


METHODS
Prospective study with sequential measurements of biological markers in a selected surgical patient group.


METHODS
University research laboratory and general university hospital (Cardiac Surgery Unit and Anesthesiology and Reanimation Unit).


METHODS
Forty-two patients undergoing elective CABS without concomitant valvular replacement.


METHODS
There were no interventions required for this study. However, patients entered into the study had CABS, sequential arterial blood samples, ECG recordings, and echocardiograms performed.


RESULTS
Pre-, intra-, and postoperative (up to 48 hrs) measurements of cardiac troponin I, MB-CK, and total creatine kinase, as well as serial electrocardiograms and echocardiograms. Perioperative infarction was assessed as the development of new persistent regional wall motion abnormalities in echocardiography together with electrocardiographic alterations and MB-CK increases. Eight patients had Q-wave PMI. All PMI patients had elevated peak cTnI values (all >9.2 ng/mL), whereas the 34 nonPMI patients had peak values <9.0 ng/mL; therefore, sensitivity and specificity (with a 9.0 ng/mL cut-off value) are 100%. MB-CK measurement peak values did not demonstrate such a high specificity and sensitivity.


CONCLUSIONS
Because of its high specificity and sensitivity, serial measurements of cTnI provide a rapid and accurate method for confirming or excluding the diagnosis of perioperative myocardial injury. cTnI evaluation can therefore be used both as an independent prognostic marker for patients undergoing cardiac surgery and as a powerful tool for detecting smaller PMIs often missed with standard PMI diagnostic criteria.
Gensini
G F
GF
Department of Internal Medicine and Cardiology, University of Florence, Italy.
Fusi
C
C
Conti
A A
AA
Calamai
G C
GC
Montesi
G F
GF
Galanti
G
G
Noferi
D
D
Carbonetto
F
F
Palmarini
M F
MF
Abbate
R
R
Vaccari
M
M
D000368:Aged; D015415:Biomarkers / Q000097:blood; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D003402:Creatine Kinase / Q000097:blood; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007118:Immunoassay; D007527:Isoenzymes; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism*; D011379:Prognosis; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019210:Troponin I / Q000097:blood*
D015415:Biomarkers; D007527:Isoenzymes; D019210:Troponin I; D003402:Creatine Kinase