The object of this study was to assess the accuracy of dipyridamole stress intravenous (IV) myocardial contrast echocardiography (MCE) using pulse inversion harmonic imaging and PESDA in the detection of perfusion defect in the patients with coronary artery disease in comparison with dipyridamole stress Tc-99m sestamibi SPECT.

Total 46 patients (29 males, mean age 64 years old) were consecutively enrolled. Patients with prior myocardial infarction were excluded. MCE and Tc-99m sestamibi SPECT were performed at the same day during rest and after 0.56 or 0.84mg/Kg dipyridamole infusion. Continuous IV infusion of PESDA (2-5 mL/min) was administered while obtaining triggered (1:1) end-systolic apical 2, 4 chamber and long axis views. Tc-99m sestamibi was injected 3 minutes after dipyridamole. Tc-99m sestamibi SPECT images were obtained one hour later. Coronary angiography was followed within two days in all patients. Tc-99m sestamibi SPECT images were matched to the sixteen segments of left ventricle according to American Society of Echocardiography for segmental comparison. Both images were analyzed visually.

Using coronary angiography as the standard, MCE showed overall sensitivity of 70.7%, specificity of 95.8%, positive predictive value (PPV) of 87.8% and negative predictive value (NPV) of 88.5% in the detection of coronary atherosclerosis (70% stenosis). Tc-99m sestamibi SPECT showed sensitivity of 75.6%, specificity of 98.9%, PPV of 96.8% and NPV of 90.6%. The overall concordance rate between MCE and Tc-99m sestamibi SPECT for the detection of perfusion defects was 86.9% (Cohen's kappa value 0.63) according to the coronary territory and 86.8% (Cohen's kappa value 0.55) according to segmental analysis.

Dipyridamole stress IV MCE using pulse inversion harmonic imaging and PESDA is feasible and comparable to Tc-99m sestamibi SPECT in identifying significant coronary stenosis and inducible myocardial perfusion defects in the patients with coronary artery disease. MCE using pulse inversion harmonic imaging seems to be a promising modality for assessing myocardial perfusion in the patients with suspected coronary artery disease.