Comparison of two-dimensional echocardiography and pulsed Doppler tissue imaging during dobutamine-atropine stress testing to detect coronary artery disease.

In order to compare the diagnostic accuracy of two-dimensional (2-D) echocardiography and pulsed Doppler tissue imaging (pDTI) during dobutamine-atropine stress testing (DAST) to detect significant coronary lesions, 41 patients underwent DAST (up to 40 microg/k/min of dobutamine with additional atropine during submaximal heart rate responses) and coronary angiography. Pulsed Doppler tissue sampling of territories corresponding to the left anterior descending (LAD), left circumflex (LCx), and right coronary arteries (RCAs) were performed in the apical four-chamber plus aorta and two-chamber apical views. The measurements were repeated at rest, at low dose (10 microg/k/min), and at peak stress. Pulsed DTI measurements included peak early systolic (Vs), peak early diastolic (Ve), and peak late diastolic (Va) velocities. Harmonic 2-D echocardiography was recorded at rest, low dose, peak stress, and recovery, and compared with pDTI assessment. Positive 2-D echocardiography was considered as infarction or ischemic response. The results were evaluated for the prediction of significant coronary stenosis (50% luminal narrowing). Feasibility of pDTI was 100%, 95%, and 98% for the LAD, the LCx, and RCA territories, respectively. At rest, Vs in territories supplied by arteries with coronary artery disease (CAD) (6.3 +/- 2.0 cm/sec) was not different from those without (6.6 +/- 2.1 cm/sec). Vs increased less in territories supplied by arteries with than without CAD (75 +/- 107% vs 102 +/- 69%, P = NS). Ve was lower in territories with CAD at rest (6.0 +/- 2.1 cm/sec vs 8.2 +/- 3.4 cm/sec, P < 0.0001) and low dose (7.2 +/- 2.1 cm/sec vs 8.8 +/- 3.6 cm/sec, P < 0.01), but similar at peak stress (7.6 +/- 3.5 cm/sec vs 8.1 +/- 3.3 cm/sec). Ve increase was similar in territories with (36 +/- 74%) than without CAD (15 +/- 6 4%). Va was similar at rest and low dose in territories with and without CAD (9.2 +/- 2.7 cm/sec vs 9.1 +/- 2.3 cm/sec and 10.9 +/- 3.1 vs 10.3 +/- 3.6 cm/sec, respectively), but lower at peak stress in territories with CAD (13.3 +/- 4.6 cm/sec vs 15.3 +/- 4.5 cm/sec, P = 0.05). The Va increase was lower in territories with CAD (43 +/- 37% vs 77 +/- 72%, P < 0.05). In a territory-based analysis, a failure to achieve Vs > or =10.5 cm/sec at peak stress in the LAD and LCx, and > or =10.0 cm/sec in the RCA territory, was found to be the more accurate limit to detect CAD in the corresponding arteries: sensitivity (95% confidence intervals): 63% (55-71), P = NS vs 2-D echocardiography: 59% (51-67); specificity 76% (68-84), P < 0.01 vs. 2-D echocardiography: 95% (89-100); and accuracy 69% (63-75), P = NS vs 2-D echocardiography: 76% (70-82). Thus, pDTI is feasible during DAST but not more accurate than 2-D echocardiography for the detection of significant CAD in a territory-based study.