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

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. 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. 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+/-3.1 vs 6.2+/-2.1 cm x 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+/-0.5 cm x s(-1), while 0+/-0.5 cm x s(-1)predicted 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) (P<0.05) and 52% (44-59) vs 51% (45-59) (P=ns). The sensitivity of pulsed-wave Doppler tissue sampling is superior to dobutamine-stress echocardiography for the assessment of myocardial viability.