[Quantification of myocardial tomography with thallium in coronary disease. Evaluation of the Cedars-Sinai technique].

OBJECTIVE

The aim of this study is to evaluate the contribution of the Cedars-Sinai quantification tomographic method (CS) in the diagnosis and localization of ischemic areas in coronary artery disease (CAD) and to optimize the threshold values proposed by CS.

PATIENTS AND METHODS

Fifty patients with clinical suspicion of CAD performed a maximal stress test by cycloergometer; thallium myocardial tomographic images were obtained; applying the CS program afterwards. The sensitivity and specificity variations obtained by changing the criteria for extent of myocardial hypoperfusion (range 1% to 100%) were used to calculate the new thresholds (CS-I), using the results of coronariographic studies as a reference. The data determined by qualitative analysis were compared with that obtained by quantitative analysis by means of CS and CS-I using coronary angiography as the standard of reference.

RESULTS

The coronary angiography showed coronary disease in 37 patients. The sensitivity for the diagnosis of CAD was superior using CS (97%) at the expense of low specificity (15%) which nevertheless improved with CS-I (54%). For the location of CAD, the visual analysis was statistically significant (p < 0.05) in the left anterior descending and right coronary arteries, CS being superior in the diagnosis of 3 vessel disease.

CONCLUSIONS

The quantification of tomographic studies with thallium by means of CS needs a readjustment of the thresholds. The tested values (CS-I) improved the CS results, although they require prospective validation. Quantitative study permits the confirmation of visual findings, being a complementary method that can be rapidly and easily interpreted, although it is not recommended as a single technique for the diagnosis of coronary disease.