Forty-three patients (40 men and 3 women, mean age 54 +/- 9 years) with coronary artery disease underwent 99mTc methoxy isobutyl isonitrile (sestamibi) myocardial scintigraphy and coronary arteriography. Sestamibi uptake and wall thickening index (WTI) were quantitatively evaluated in each myocardial segment. Segments were divided into group 1 (normal coronary arteries, no. = 94), group 2 (coronary artery stenosis 50-99%, no. = 79), and group 3 (coronary artery stenosis 100%, no. = 42). Group 3 segments were subdivided into group 3A (with collaterals, no. = 18) and group 3B (without collaterals, no. = 24) segments. Both sestamibi uptake and WTI were significantly lower (p < 0.01) in group 3 than in groups 1 and 2. However, only WTI was significantly reduced (p < 0.01) in group 3B vs group 3A. Diagnostic capabilities (i.e. identification of segments supplied by stenosed coronary arteries) of sestamibi uptake, WTI, and a combination of both variables with a discriminant function were compared by analysis of receiver operator characteristic curve (ROC) areas. The diagnostic capabilities of sestamibi uptake (ROC area = 0.65 +/- 0.04) were significantly lower (p < 0.05) than those of WTI (ROC area = 0.81 +/- 0.03) and discriminant function (ROC area = 0.83 +/- 0.03). In conclusion, our data suggest that combined analysis of myocardial perfusion and regional ventricular function may increase the diagnostic accuracy of sestamibi myocardial scintigraphy in identifying myocardial segments supplied by stenosed coronary arteries.