The evaluation of the coronary flow velocity reserve (CFVR) in the left anterior descending coronary artery (LAD) during a Dobutamine stress echocardiography (DSE) is few realized in current practice. A threshold<2 would be in favor of myocardial ischemia according to some studies. The main purposes of this study are to analyze the feasibility of the CFVR and to search for a pathological threshold in order to make it a complementary tool in the non-invasive detection for myocardial ischemia in the LAD territory.

One hundred and ninety-six consecutive patients referred for detection of myocardial ischemia with contrast-enhanced DSE were evaluated in the GHPSJ from July 2017 to July 2018. CFVR was calculated as a ratio of the distal LAD diastolic peak velocity at rest and peak of stress. The result of the echocardiography was rendered only on the analysis of wall motion abnormalities as a standard reference.

The feasibility of CFVR is 94.9%. The pathological threshold of CFVR is≤2.1 (sensitivity of 84.2%, specificity of 70%). The CFVR is altered at 1.87±0.52 in the positive DSE in the LAD territory vs. 2.67±0.91 in the normal ones (P<0.001). No significant difference was found between the diabetic and non-diabetic populations (P=0.194).

The coronary reserve is a non-invasive feasible technique in current practice, sensitive, allowing to add a quantitative criterion to the detection of a myocardial ischemia during a DSE even in non-echogenic patients who needed contrast agent. (Figure 1, Cut off value of CFVR).