Are enzymatic tests good indicators of coronary reperfusion?

OBJECTIVE

To assess the accuracy of four enzymatic tests, including early release rates of creatine kinase and alpha-hydroxybutyrate dehydrogenase, in assessing coronary reperfusion after thrombolytic therapy.

DESIGN

A prospective clinical trial identifying patients with a successful thrombolytic treatment.

PATIENTS

Eighty nine patients with acute myocardial infarction were studied. Arteriography showed a closed infarct related artery in all of them. Reperfusion due to thrombolysis occurred in 74 patients and there was no reperfusion in 15 patients.

RESULTS

The 74 patients showing coronary reperfusion had a significantly shorter time to peak creatine kinase activity, higher early release rates for creatine kinase and alpha-hydroxybutyrate dehydrogenase, and a more rapid release of alpha-hydroxybutyrate dehydrogenase (ratio of cumulative release of alpha-hydroxybutyrate dehydrogenase during the first 24 hours to that 72 hours after infarction). All these differences were statistically significant (p less than 0.001). Optimum cut off levels were determined with decision level plots and the accuracy of the four enzymatic tests was calculated. Accuracy was low for all four tests (73%, 70%, 70%, and 82%).

CONCLUSION

None of the four enzymatic tests accurately predicted the perfusion state of the infarct related coronary artery after thrombolysis. These tests cannot be used reliably in routine clinical practice as non-angiographic markers of coronary reperfusion.