Value of low dose dobutamine real-time myocardial contrast echocardiography in the assessment of coronary artery disease

ObjectiveTo evaluate the value of quantitative real-time myocardial contrast echocardiography (RT-MCE) combined with low dose dobutamine stress test in the detection of coronary artery disease (CAD), and to assess the contribution of collateral blood flow (CBF) to myocardial perfusion.Methods Twenty-six hospitalized patients referred for coronary angiography and subsequent revascularization underwent routine echocardiography, RT-MCE at baseline and after low dose dobutamine administration. The images of RT-MCE were analyzed quantitatively from microbubble replenishment curves for myocardial perfusion and its reserve by using the QLab software.Results At baseline, both β and A×β (but not A) were decreased with the increase of severity of coronary stenosis (P0.01). Under dobutamine stress, A, β and A×β values were decreased with the increase of severity of coronary stenosis (P0.01), Graded decreasing in the reserves of A, β and A×β were observed with increasing coronary stenosis severity (P0.01). Furthermore, significant differences in β, A×β, and WMS were observed between segments with CBF and those without. Conclusion Quantitative RT-MCE in conjunction with dobutamine stress can be used as a sensitive measure to identify and stratify CAD as well as to assess the contribution of collateral blood flow.