Simultaneous dobutamine stress echocardiography and 99mTc-tetrofosmin three-head single-photon emission computed tomography in patients with suspected coronary artery disease.

OBJECTIVES AND BACKGROUND

Dobutamine stress echocardiography and 99mTc-tetrofosmin single-photon emission computed tomography (T-SPECT) were performed simultaneously in subjects in whom coronary artery disease (CAD) had been proven or excluded at coronary angiography, in order to establish their accuracy and agreement in the diagnosis of CAD, and in localisation and evaluation of the extension of ischaemia. No simultaneous comparison of the two techniques has been performed previously.

METHODS

Seventy patients (50 men, mean age 63 +/- 10 years, 21 with previous myocardial infarction) underwent simultaneous dobutamine stress echocardiography and T-SPECT. The response to stress was blindly and independently analysed, adopting a 16-region segmentation and referring to the three major coronary arteries.

RESULTS

Sixty-two patients (agreement 89%, kappa = 0.776) and 91% of left ventricular regions (kappa = 0.665) were classified concordantly, independently of the presence or absence of previous myocardial infarction (90%, kappa = 0.740 versus 91%, kappa = 0.589, respectively). At coronary angiography, 47 patients had CAD (disease prevalence 67%). The sensitivity and specificity of stress echocardiography for the diagnosis of anterior descending, circumflex and right coronary artery disease were 62, 78 and 73%, and 79, 79 and 83%, respectively. The corresponding values for T-SPECT were 70, 75 and 78%, and 94, 79 and 90%, respectively.

CONCLUSIONS

These data indicate a high concordance between wall motion abnormalities observed using stress echocardiography and perfusion defects observed using T-SPECT; their sensitivity in identifying critical stenoses was similar. Inadequate stressor amounts, and less frequently hyperdynamic regional response may reduce the accuracy of stress echocardiography, while dobutamine effects on coronary flow may prevent T-SPECT from showing subtle flow maldistributions in the presence of worsened wall motion.