Usefulness of the MOSAIC (measurement of stenosis by aliasing coronary flow) method using transthoracic color Doppler echocardiography in unstable angina patients.

BACKGROUND

The aim of this study was to investigate the significance of the MOSAIC (measurement of stenosis by aliasing coronary flow) method for the detection of proximal left coronary stenosis in patients with unstable angina (UA) using transthoracic Doppler echocardiography (TTDE).

METHODS

Patients (n=107) with UA were evaluated. Proximal left coronary flow was sought in the short axis (SAX) at the aortic root level using color Doppler guidance. When detected coronary flow showed color aliasing, the color velocity range was gradually increased until color aliasing nearly disappeared. Then, the color baseline was shifted until the color flow showed "isovelocity".

RESULTS

Proximal coronary flow was detected in 86 (80.4%) of 107 patients. In these 86 patients, an optimal cutoff value of isovelocity ≥ 47.5 cm/s predicted significant coronary stenosis (percent diameter stenosis ≥ 70%) of the proximal left anterior descending (AHA segment 6) or left main coronary artery with a sensitivity of 88%, specificity of 97%, positive predictive value of 98%, and negative predictive value of 86%. In all 107 patients, the same cutoff value predicted significant coronary stenosis with a sensitivity of 78%, specificity of 98%, positive predictive value of 98%, and negative predictive value of 81%.

CONCLUSIONS

The MOSAIC method may play a complementary role in expeditious risk stratification and decision making in patients with UA.