Is serum myoglobin an early marker of reperfusion in thrombolysed AMI?

Background and objectives

Since early reperfusion of an occluded artery proved to be the essential mechanism of the improved prognosis and mortality reduction, better prediction of successful thrombolysis had become a priority.

Our study aimed to prove that serum myoglobin determination allows better prediction of blood flow re-establishment.

As successful reperfusion causes an earlier release of biochemical markers of myocardial necrosis, we supposed that early and repeated dosage of serum myoglobin would permit a better prediction of recanalisation.

Methods

We studied the serum myoglobin levels in 47 patients presenting an AMI: 37 intravenous patients were treated by thrombolysis (rTPA); five by emergency TGA; and four patients presented a contraindication to either one methods. Thirty-two from 37 patients were reperfused during the first 90 min, five were not.

Results

A fourfold increase in the first 90 min is a good predicting factor of reperfusion (78% sensibility, 89% positive predicting value, 40% specificity, 25% negative predicting value). The low results for specificity and negative predicting value are probably due to the small number of non-reperfused patients.

Conclusion

Determination of serum myoglobin levels during the first 90 min of an AMI treated by intravenous thrombolysis may accurately identify successful reperfusion if used in association with the other reperfusion predicting factors (resolution of the ST-segment elevation, pain resolution, arrhythmias), but larger series are necessary before generalisation of this technique. Thus, lower cost and rapid assay device make this method interesting for early assessment of myocardial reperfusion.