TC-99M SESTAMIBI MYOCARDIAL TOMOGRAPHY BASED ON DIPYRIDAMOLE-ECHOCARDIOGRAPHY TESTING IN HYPERTENSIVE PATIENTS WITH CHEST PAIN

The non-invasive diagnosis of coronary artery disease in hypertensives with chest pain is an important clinical concern because all exercise -dependent tests display limited feasibility and diagnostic accuracy; by contrast, dipyridamole echocardiography testing has been shown to h ave a similar feasibility and accuracy in hypertensive and normotensiv e subjects. The aim of this study was to evaluate the diagnostic capab ility of technetium-99m sestamibi tomography based on dipyridamole ech ocardiography testing in hypertensives with chest pain, and to compare the scintigraphic results with those of coronary angiography, exercis e electrocardiography and dipyridamole echocardiography. Forty subject s with mild to moderate hypertension, chest pain and no previous myoca rdial infarction were submitted to Tc-99m-sestamibi tomography (at res t and after high-dose dipyridamole echocardiography) and to exercise e lectrocardiography testing. At coronary angiography 22 patients (group A) had significant epicardial coronary artery disease (greater than o r equal to 70% stenosis of at least one major vessel) and 18 normal ma in coronary vessels (group B). Dipyridamole Tc-99m-sestamibi imaging w as positive in 21/22 patients of group A and in 5/18 of group B. Dipyr idamole echocardiography was positive in 18/22 patients of group A and in 5/18 of group B. Exercise electrocardiography was positive in 15/2 2 patients of group A and in 11/18 of group B. Four out of five subjec ts in group B with positive results in all the tests showed a slow run -off of angiographic contrast medium, probably due to small-vessel dis ease. Significant epicardial coronary artery disease in hypertensives with chest pain is unlikely when dipyridamole Tc-99m-sestamibi tomogra phy is negative. When scintigraphy is positive, either epicardial coro nary artery disease or a small-vessel disease condition is possible. T he association of scintigraphy with dipyridamole echocardiography test ing allows the assessment of contractile function and myocardial perfu sion by a single pharmacological stress.