Sequential teboroxime imaging during and after balloon occlusion of a coronary artery

Department of Medicine, University of Massachusetts Medical Center, Worcester 01655.

OBJECTIVES. We sought to assess whether sequential teboroxime imaging can rapidly evaluate vessel patency and identify the coronary artery occluded in patients undergoing balloon occlusion of a coronary artery. BACKGROUND. Intravenous thrombolytic therapy results in successful reperfusion of the infarct-related artery in only 50% to 80% of cases. A noninvasive technique to serially evaluate coronary perfusion would identify patients who might benefit from other interventions such as emergency percutaneous transluminal coronary angioplasty, coronary artery bypass grafting or increased intensity of thrombolytic therapy. METHODS. Teboroxime scans were performed during balloon occlusion in 15 nonconsecutive patients undergoing angioplasty of a major coronary artery. Equivalent views were repeated after successful angioplasty. RESULTS. The mean time between balloon occlusion and reperfusion imaging was 1.6 +/- 0.6 h. The mean number of defects decreased significantly from 4.13 +/- 1.01 during balloon occlusion to 0.27 +/- 0.44 after reperfusion (p = 0.0006). There was a 30% decrease in the defect/normal zone count/pixel ratios during balloon occlusion and normalization of these ratios after reperfusion (p = 0.0006). The scans correctly identified all nine left anterior descending coronary artery occlusions and both right coronary artery occlusions. One of the four left circumflex coronary artery occlusions was incorrectly identified as a right coronary artery occlusion by scan criteria. Overall, the scans correctly identified the occluded artery 93% of the time (kappa = 0.88). The scan was 100% accurate for distinguishing occlusion of the left anterior descending coronary artery (n = 9) from occlusions of the left circumflex or right coronary artery (n = 6). CONCLUSIONS. We believe that this is the first clinical study to demonstrate that sequential planar imaging with teboroxime can 1) rapidly detect acute coronary artery occlusion and reperfusion, and 2) identify the occluded coronary artery. A trial comparing rapid sequential teboroxime imaging with coronary angiography in patients receiving thrombolytic therapy for acute myocardial infarction is warranted.