DOBUTAMINE STRESS ECHOCARDIOGRAPHY COMPARED WITH EXERCISE TL-201 SINGLE-PHOTON EMISSION COMPUTED-TOMOGRAPHY IN DETECTING CORONARY-ARTERY DISEASE - EFFECT OF EXERCISE LEVEL ON ACCURACY

Dobutamine stress echocardiography (DSE) and exercise thallium-201 sin gle-photon emission computed tomography (SPECT) were compared for the accuracy in detecting coronary artery disease (CAD) in 51 consecutive patients. Twenty-six (group 1) of the 51 patients achieved adequate ex ercise end points, and 25 (group 2) did not. There were 38 patients wi th angiographically documented CAD. The overall sensitivity of DSE and thallium-201 SPECT in detecting CAD was 92 and 76% (p = NS), and the specificity was 77 and 77% (p = NS), respectively. The sensitivity of DSE is the same as that of SPECT in group 1 (90 vs. 90%; p = NS) and h igher than that of SPECT in group 2 (94 vs. 61%; p < 0.05). In patient s with CAD without a history of acute myocardial infarction or patholo gical Q wave on resting electrocardiogram, the sensitivity of DSE is t he same as that of SPECT in group 1 (82 vs. 82%; p = NS) and also high er than that of SPECT in group 2 (90 vs. 40%; p = 0.03). The sensitivi ty in detecting individual coronary artery lesions with DSE and thalli um-201 SPECT was not affected by the exercise level. The agreement bet ween DSE and thallium SPECT in detecting patients with CAD was 88% in group 1 (kappa = 0.69; p < 0.001) and 76% in group 2 (kappa = 0.45; p = 0.01). The agreement in detecting vascular territories with ischemia was 68% in group 1 (kappa = 0.30; p < 0.01) and 75% in group 2 (kappa = 0.33; p < 0.001). The agreement in detecting vascular territories w ith a scar was 87% in group 1 (kappa = 0.55; p < 0.001) and 85% in gro up 2 (kappa = 0.44; p < 0.001). In conclusion, the sensitivity and spe cificity of DSE in detecting CAD are similar to that of thallium-201 S PECT with an exercise level greater than or equal to 85% of the maxima l predicted heart rate, However, in patients who cannot exercise adequ ately, DSE is more accurate than thallium SPECT. The agreement between DSE and thallium SPECT in detecting patients with CAD and identifying ischemia of individual vascular territories is also affected by the e xercise level.