Teboroxime is a marker of reperfusion after myocardial infarction

Abstract

Background: It has been shown that serial teboroxime imaging can rapidly assess coronary perfusion in viable myocardial distributions. However, the myocardial uptake of teboroxime after reperfusion of acutely infarcted myocardium has not been critically evaluated. The study object was to assess whether teboroxime uptake in acutely infarcted myocardium is linearly related to blood flow.

Methods and results: Seventeen New Zealand rabbits underwent occlusion of the left circumflex coronary artery for 1 hour. The animals were reperfused for 2 hours and, just before they were killed, teboroxime was injected. The infarct was delineated by triphenyltetrazolium chloride staining. Normalized blood flow and myocardial teboroxime distribution in the infarcted myocardium was determined by gamma well counting. Ex vivo planar images of the left ventricle were also acquired. Transmural myocardial infarction was documented in all 17 rabbits. The mean infarct size +/- one standard deviation was 25.5% +/- 10.7% (range, 11.9% to 43.3%). There was a direct linear relationship between normalized reperfusion flow and myocardial teboroxime distribution in the infarct zone (r = 0.91). A direct linear relationship between defect size and normalized infarct zone reperfusion was also evident on the ex vivo planar studies (r = 0.70).

Conclusion: This study shows that the initial uptake of teboroxime in acutely infarcted myocardium is linearly related to blood flow. Teboroxime has properties that are well suited for the early evaluation of infarct zone perfusion.