Doppler tissue velocity sampling improves diagnostic accuracy during dobutamine stress echocardiography for the assessment of viable myocardium in patients with severe left ventricular dysfunction

Abstract

Background Both nuclear imaging with F18-fluorodeoxyglucose and dobutamine stress echocardiography have been used to identify viable myocardium, although dobutamine–stress echocardiography has been demonstrated to be the less sensitive of the two. Aim To compare the accuracy of pulsed-wave Doppler tissue sampling with dobutamine–stress echocardiography for the detection of viable myocardium, using F18-fluorodeoxyglucose imaging as a reference. Methods Forty patients with chronic coronary artery disease and left ventricular dysfunction (mean ejection fraction 33±11%), underwent F18-fluorodeoxyglucose imaging, dobutamine–stress echocardiography and pulsed-wave Doppler tissue sampling. Evaluation was performed using a six-segment model. Results Visual assessment by resting echo was feasible in 230 out of 240 segments (96%); 177 (77%) segments showed severe dyssynergy at rest. F18-fluorodeoxyglucose imaging showed viability in 95 (54%) segments while 82 (46%) were non-viable. Ejection phase velocity at rest was not significantly different; ejection velocities during low-dose and peak-dose dobutamine, however, were significantly higher in viable myocardium (8·6±2·9 vs 6·0±1·8 and 9·3±31 vs 6·2±2·1cm.s⁻¹). Using receiver operating characteristic curves the optimal cut-off value for viability assessment was an increase in the ejection phase velocity low-dose of 1±0·5cm.s⁻¹, while 0±0·5cm.s⁻¹predicted non-viability. The sensitivity and specificity (95%CI) of pulsed-wave Doppler tissue sampling and dobutamine–stress echocardiography for the prediction of viability was respectively 87% (82–92) vs 75% (67–81) (PP=ns). Conclusions The sensitivity of pulsed-wave Doppler tissue sampling is superior to dobutamine–stress echocardiography for the assessment of myocardial viability.