Feasibility of coronary flow velocity reserve during semi-supine exercise echocardiography: a single center study of 3,014 patients

Aim: There is a lack of studies that analyzed factors influencing on feasibility of coronary flow velocity reserve (CFVR) during exercise stress echocardiography (SE). The aim of the study was to define the feasibility of assessment of CFVR during exercise through SE depending on experience, techniques, and clinical factors. Methods: This is a single-center study. SE was performed using three generations of echo systems in five consecutive cohorts of patients by experienced and novice specialists. All patients performed a supine bicycle testing. CFVR was calculated in the middle/middle-distal parts of the left anterior descending artery (LAD). Three different adjustment settings were used for LAD visualization. Results: The study included 3,014 patients (59 years old ± 11 years old, 54% males). Age [odds ratio (OR) 0.98, 95% confidence interval (CI) 0.96–0.99, P < 0.01], body mass index (BMI; OR 0.95, 95% CI 0.91–0.98, P < 0.003), rest heart rate (OR 0.98, 95% CI 0.97–0.99, P < 0.0005) and doctor’s experience (OR 2.7, 95% CI 1.57–4.53, P < 0.0003) were independent factors that influence on feasibility. The feasibility of CFVR assessment during exercise SE in the whole population by experienced doctors was 89.4%. The feasibility of CFVR assessment of LAD in obese patients performed by experienced doctors using modern echo machines and new techniques was high (86.0%). Conclusions: Coronary artery velocity reserve during supine exercise SE is a feasible, non-invasive available tool. The new generation echo machine and the new techniques provide a good feasibility of CFVR assessment, even in novice doctors. Despite a lower level of possibility to assess CFVR in obese patients or with a higher resting heart rate, this method is feasible in a great majority of such patients.