Estimation of infarct size by single measurements of creatine kinase levels in patients with a first myocardial infarction.
OBJECTIVE
Enzymatic estimation of infarct size is desirable in the reperfusion era, because a possible discrepancy with the observed asynergic area of the left ventricle may suggest the presence of stunned myocardium. Unfortunately, timely myocardial reperfusion produces a rapid washout of creatine kinase (CK) in blood flow, which overestimates infarct size. In this perspective, we investigated whether the mid-terminal portion of the CK time-activity curve could predict infarct size more reliably.


METHODS
Enzymatic infarct size was calculated by peak CK levels, the CK area under the curve and by single CK values, in 103 patients with a first ST-elevation myocardial infarction, and compared to the left ventricular akinetic area. The wall motion asynergy score at follow-up was considered as the actual infarct size.


RESULTS
In patients with peak CK within 10 h of symptom onset, CK levels at 30 h showed a high independent correlation (r = 0.83; P < 0.001) with infarct size. In patients with late peak CK (> 10 h), CK levels at 12 h turned out to be the best predictor of infarct size (r = 0.55; P < 0.01). At multivariate regression analysis, peak CK was the best predictor of infarct size in the whole population (r = 0.61; P < 0.001).


CONCLUSIONS
In patients with ST-elevation myocardial infarction and early peak CK, infarct size at follow-up could be better estimated with single values of the mid-terminal portion of the CK time-activity curve.
Di Chiara
Antonio
A
Division of Cardiology, Department of Cardiopulmonary Sciences, S Maria della Misericordia Hospital, Udine, Italy. dichiara.antonio@aoud.sanita.fvg.it
Plewka
Michal
M
Werren
Marika
M
Badano
Luigi P
LP
Fresco
Claudio
C
Fioretti
Paolo M
PM
D000368:Aged; D000704:Analysis of Variance; D015906:Angioplasty, Balloon, Coronary; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood*; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007558:Italy; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000201:enzymology* / Q000473:pathology* / Q000503:physiopathology / Q000628:therapy; D015425:Myocardial Reperfusion; D011237:Predictive Value of Tests; D012107:Research Design; D012189:Retrospective Studies; D013318:Stroke Volume; D015912:Thrombolytic Therapy; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000201:enzymology* / Q000473:pathology* / Q000503:physiopathology / Q000628:therapy
D015415:Biomarkers; D003402:Creatine Kinase