Exercise echocardiography and single photon emission computed tomography in patients with left anterior descending coronary artery stenosis

To compare the diagnostic value of exercise echocardiography and perfusion single photon emission computed tomography (SPECT) in the detection of the presence and the severity of coronary artery disease, we studied 21 patients with isolated stenosis of different degree of the left anterior descending artery. Both echocardiography and SPECT were performed in conjunction with the same symptom-limited bicycle exercise test. Positivity of the test was based on the presence of exercise-induced wall motion abnormalities and transient perfusion defects, respectively. For both tests, an ‘ischemic’ score was derived, as index of extent and severity of myocardial ischemia. Coronary arteriography was evaluated by caliper. The agreement between exercise echocardiography and SPECT for the presence of coronary artery disease was 90%; the discordance was due to two patients with positive echocardiography and negative SPECT. A good correlation between ischemic wall motion and perfusion score indices was found (r=0.78, p<0.0001. Moreover, the percent diameter stenosis was well correlated with both ischemic indices (r= 0.75, p<0.0001; r=67, p<0.001, respectively). In patients with a positive test, the mean value of ischemic wall motion score index was higher in patients with a diameter stenosis ≥ 70% than in patients with a diameter stenosis <70% (0.59 ± 0.19 vs 0.29 ± 0.12, p < 0.01); a similar trend was found for ischemic perfusion score index (0.51 ± 0.35 vs 0.27± 0.12, ns). The results of this study indicate that in patients with single vessel disease of left anterior descending artery exercise echocardiography and SPECT give the same information on the presence, the extent and the severity of myocardial ischemia.