[The use of myoglobin for the early diagnosis of reperfusion in acute myocardial infarct].

Myoglobin (Mb) is an intracardiac protein known to be rapidly released after onset of reperfusion. The new automated latex-enhanced nephelometric immunoassay is an interesting fast alternative to the other methods. Therefore we sought to assess the accuracy of rapid rise of Mb concentration to predict the success of reperfusion. Thirty consecutive patients, admitted to the coronary care unit for first acute Q-wave myocardial infarction, were prospectively studied. They underwent thrombolysis 126 +/- 45 min (range 30-180) after onset of symptoms. Mb determinations were obtained before starting therapy and, thereafter, hourly for 5 hours, and after 8 and 12 hours. The usual non invasive markers of reperfusion were considered, and coronary arteriography was performed in all patients at 5.5 +/- 0.9 days (range 1-6). In 23 patients (77%) patent infarct-related artery (IRA) (TIMI II-III) and in 7 (23%) occluded IRA (TIMI 0-I) was observed at coronary arteriography. We modified the judgment in 3 cases (10%) with occluded IRA. All reperfused patients (Group A) showed a rapid rise of Mb concentration with a mean time to peak occurring 133 +/- 80 min (range 60-180) after therapy. Mean value of unreperfused patients (Group B) was 330 +/- 173 min (range 180-420). We retrospectively stated a time to peak of Mb concentration within 180 min as diagnostic threshold for reperfusion. Sensitivity was 100%, specificity 50%, positive predictive value 93%, negative predictive value 100%. The results of this study confirm that Mb release kinetics may play an interesting role in the early prediction of patency of IRA in acute myocardial infarction after thrombolysis.(ABSTRACT TRUNCATED AT 250 WORDS)