Objectives: The purpose of this study was to examine whether coronary reperfusion can be diagnosed rapidly and accurately by myoglobin measurements.
Background: When intravenous thrombolysis is used for acute myocardial infarction, it is important to determine coronary reperfusion rapidly and noninvasively so that further treatment can be initiated.
Methods: We determined myoglobin, creatine kinase (CK) and creatine kinase, MB fraction (CK-MB) isoenzyme levels in 63 patients with acute myocardial infarction with total occlusion of the infarct-related artery that was confirmed by coronary angiography. Myoglobin was measured by turbidimetric latex agglutination, which has an assay time of 10 min. We measured myoglobin, CK and CK-MB every 15 min in 45 patients with and 18 patients without reperfusion. The condition of the infarct-related artery was confirmed every 5 to 8 min by coronary angiography.
Results: The rate of increase in myoglobin, CK, and CK-MB at 15, 30, 45 and 60 min after treatment and reperfusion was significantly higher in the reperfused than in the nonreperfused group. In the reperfused group, the rate of increase in myoglobin was significantly higher than the corresponding rate of increase in CK and CK-MB at 15, 30 and 45 min after reperfusion. When reperfusion was evaluated on the basis of a cutoff level (myoglobin > or = 2.0, CK > or = 1.8, CK-MB > or = 1.5), the predictive accuracy of myoglobin (95%) was significantly higher than that of CK (68%) and CK-MB (73%) at 15 min after reperfusion.
Conclusions: Coronary reperfusion can be rapidly and accurately detected by measurement of the plasma myoglobin every 15 min.