Relationship between the location of the most severe myocardial perfusion defects, the most severe coronary artery stenosis, and the site of subsequent myocardial infarction.

UNLABELLED: This study evaluated the relationship between the location of the most severe myocardial perfusion defects, the most severe coronary artery stenosis, and the site of subsequent acute myocardial infarction (AMI). METHODS: Of 3,180 patients who were admitted with a diagnosis of AMI, we identified 44 patients who had undergone previous myocardial perfusion SPECT. Thirty-one of them also had previous coronary angiography. The relationship between the location of the myocardial perfusion defects, the coronary artery stenosis, and the site of subsequent AMI was studied in these patients. RESULTS: The concordance between the location of the most severe reversible defects detected by SPECT and the site of subsequent AMI was 71% (kappa = 0.499). The concordance between the most severe stenosis detected by coronary angiography and the site of subsequent AMI was 64% (kappa = 0.451). However, kappa values for SPECT and coronary angiography were good when the interval between these investigations and subsequent AMI was <3 mo (0.724 and 0.661, respectively), for moderate to severe perfusion defects (0.719), and for 90%-99% coronary stenosis (0.626). CONCLUSION: The culprit lesion is not always the one that is manifested by the most severe reversible perfusion defect or the most critical coronary artery stenosis. Myocardial SPECT and coronary angiography can predict the location of a future AMI in 71% and 64% of patients, respectively. The percentage is higher when the interval between investigations and subsequent AMI is <3 mo, for moderate to severe perfusion defects, and for 90%-99% coronary stenosis.

[Quantification of myocardial ischemia in regions dependent on occluded coronary arteries in patients without previous infarction]. / Cuantificación de la isquemia miocárdica en regiones dependientes de arterias coronarias ocluidas de pacientes sin infarto previo.

INTRODUCTION AND OBJECTIVES: The aim of this study is to assess myocardial ischemia in regions with no infarction dependent occluded coronary arteries. PATIENTS AND METHODS: 149 patients with proved coronary artery disease and without previous myocardial infarction were studied by 99mTc-MIBI SPECT (long protocol) and coronary angiography. The extent of the uptake reversibility was quantified in 3 regions (antero-septal, inferior and lateral) of the polar maps, assessing the percentage of each region that had a > 10% difference resulting from the rest uptake minus the stress uptake. The regions dependent on one occluded artery were compared to those dependent on non-occluded arteries. In the regions dependent on one occluded artery a comparison was also made between those which had a good collateral circulation and those which did not. RESULTS: Fifty-four out of 149 patients (36%) had at least one occluded coronary artery (20 anterior descending, 22 right and 27 circumflex coronary arteries). In the visual analysis, reversible defects were observed in all patients with occlusion of the anterior descending and the right coronary artery, but only in half of the occlusions of the circumflex coronary artery. The extent of this reversibility was significantly higher in the regions dependent on occluded arteries and was highly variable, though lower when good collateral circulation was present. CONCLUSIONS: Reversible defects were always observed in the occlusions of the left anterior descending and right coronary arteries, but only in half of those of the circumflex artery. The extent of the ischemia was higher in the regions dependent on one occluded coronary artery, mainly when there was an absence of good collateral circulation.