COMPARISON OF DOBUTAMINE STRESS ECHOCARDIOGRAPHY AND TC-99M SESTAMIBISINGLE-PHOTON EMISSION TOMOGRAPHY FOR THE DIAGNOSIS OF CORONARY-ARTERY DISEASE IN HYPERTENSIVE PATIENTS WITH AND WITHOUT LEFT-VENTRICULAR HYPERTROPHY

Stress echocardiography has been considered an accurate method for the diagnosis of coronary artery disease in hypertensive patients and in patients with left ventricular hypertrophy. In contrast, the specifici ty of myocardial perfusion scintigraphy in these patients has been que stioned. The aim of this study was to compare the accuracy of these tw o imaging modalities in conjunction with dobutamine stress test for th e diagnosis of coronary artery disease in hypertensive patients with a nd without left ventricular hypertrophy. Dobutamine (up to 40 mu g kg( -1)min(-1)) stress echocardiography in conjunction with sestamibi (MIB I) single-photon emission tomography (SPET) was performed in 84 patien ts with the diagnosis of systemic hypertension who had been referred f or evaluation of myocardial ischaemia. Ischaemia was defined as new or worsened wall motion abnormalities at echocardiography and reversible perfusion defects at SPET. Significant coronary artery disease (great er than or equal to 50% luminal diameter stenosis) was detected in 66 patients (79%). The sensitivity, specificity and accuracy of the ischa emic pattern at echocardiography for the diagnosis of coronary artery disease were 73% (CI 63%-82%), 83% (CI 75%-91%) and 75% (CI 66%-84%), those for MIBI were 67% (CI 57%-77%), 83% (CI 75%-91%) and 70% (CI 60% -80%) respectively (P = NS vs echocardiography). Significant stenosis was detected in 123 (49%) of the 252 analysed coronary arteries. The s ensitivity, specificity and accuracy of echocardiography for the regio nal diagnosis of coronary artery disease were 63% (CI 56%-69%), 90% (C I 86%-94%) and 77% (CI 72%-82%). Those for MIBI were 58% (CI 51%-64%), 91% (CI 87%-94%) and 75% (CI 69%-80) respectively (P = NS vs echocard iography). Left ventricular hypertrophy was detected in 59 patients (7 0%) by echocardiography and did not influence the overall or regional specificity of echocardiography or MIBI SPET. It is concluded that in hypertensive patients, dobutamine stress echocardiography and MIBI SPE T have a comparable accuracy for the overall and regional diagnosis of coronary artery disease. Hypertensive patients with or without left v entricular hypertrophy should not be considered unsuitable candidates for stress myocardial perfusion scintigraphy.