MINIMAL RESIDUAL CORONARY OBSTRUCTIONS IN PATIENTS WHO SUFFERED A FIRST MYOCARDIAL-INFARCTION - A PROSPECTIVE-STUDY COMPARING CORONARY ANGIOGRAPHY AND EXERCISE THALLIUM SCINTIGRAPHY

The purpose of the present study was to correlate the presence of mini mal coronary obstruction (less than or equal to 50%) assessed by coron ary angiography with the presence of myocardial scar and ischemia dete cted by thallium-201 myocardial perfusion imaging. The study included 83 consecutive patients (74 men and 9 women) with a mean age 55.4 +/- 8.5 years who suffered a first myocardial infarction and did not under go thrombolytic therapy. In all patients, coronary angiography, left v entriculography, and exercise thallium-201 tomographic scintigraphy we re performed within 3 to 5 months of the myocardial infarction. Corona ry arteriograms showed minimal residual obstructions in 37 (45%) patie nts. Of a total of 54 patients with less than or equal to 50% obstruct ion, 18 showed persistent defects and 22 reversible defects on thalliu m scintigrams. The present study showing estimated angiographic stenos is of less than or equal to 50% as being responsible either for myocar dial scar or myocardial ischemia on postexercise thallium scintigrams leads us to conclude that percent value of stenosis does not accuratel y predict the pathophysiologic significance of coronary atheroscleroti c lesions in patients who suffer a myocardial infarction. After a firs t myocardial infarction, coronary angiographies and thallium-201 scint igrams are complementary for an optimal treatment strategy for selecte d subsets of patients.