Non-invasive methods to assess reperfusion in acute myocardial infarction: Enzymes and cardiac imaging gammagraphy with MIBI-SPECT

Introduction. Several studies point out the importance of what is called rescue angioplasty or fibrinolysis when thrombolysis has been ineffective in acute myocardial infarction. Therefore, it is necessary to make use of new non-invasive methods to asses reperfusion and to safely establish that such a treatment has not been effective. Patients and method. We present a work which is based on the assessment of patients with acute myocardial infarction treated with or without fibrinolysis. After determining cardiac enzymatic profiles of creatin kinase and MB isoform (time course, peak, appearance rate constant time-activity: K-1). With cardiac imaging gammagraphies Tc-99m-isonitrile-single-photon emission computed tomography pre and post treatment after to calculating myocardium at risk, salvage and relationship. Results. In patients treated with fibrinolysis, the salvage myocardium was higher (8.3% vs 3.0%; p < 0.05). Considering that an improvement in perfusion defect (salvaged myocardium/myocardium at risk) higher than 30% can be viewed as an effective reperfusion, we can see that the percentage in the group treated with fibrinolysis being 45.8%, and the percentage in the group under conventional treatment being just 6.7%. Patients with acute myocardial infarction treated with fibrinolysis show much shorter start of rise-peak time and pain-peak time, all this with very significant differences for the creatin kinase (p < 0.0001) as well as for the MB (p < 0.001). Patients with reperfusion show a rapid increase in activity enzymatic, as demostred by the pain-peak time variable and the appearance rate constant time-activity (K-1), with very significant differences in the latter (p < 0.0001). In relation with gammgraphy, values of K-1 higher or equal to 0.19 for the creatin kinase and 0.14 for the MB isoform, achieved a sensibility of 83% and 91%, and a specificity of 85% and 80% respectively, to asses reperfusion. Conclusion. We think that cardiac imaging gammagraphy with isonitriles as well as as determination of the appearance rate enzymatic constant time-activity, can be useful in monitoring treatment with fibrinolysis in infarction patients, New studies are needed to assess these same aspects, with a lesser number of enzymatic determinations.