Noninvasive diagnosis of restenosis by transthoracic Doppler echocardiography after percutaneous coronary intervention: comparison with exercise Tl-SPECT.

OBJECTIVE

Noninvasive methods that have the ability to accurately detect restenosis have been desired in the selection of patients requiring further angiographic evaluation. The present study sought to evaluate the diagnostic potential of transthoracic Doppler echocardiography (TTDE), a noninvasive method for evaluating coronary flow velocity reserve (CFVR), in detecting restenosis after percutaneous coronary intervention (PCI).

METHODS

We studied 107 consecutive patients 6 months after undergoing successful PCI on the left anterior descending coronary artery (LAD) lesions for relief of angina pectoris. The flow velocity in the distal LAD was measured by TTDE both at rest and during intravenous infusion of adenosine triphosphate. CFVR was calculated as the ratio of hyperemic to basal mean diastolic flow velocities. We defined a reversible perfusion defect in exercise Tl-201 single-photon emission computed tomography (SPECT) as restenosis. The CFVR measurements by TTDE were compared with the results of SPECT.

RESULTS

Complete TTDE data were acquired for 105 of the 107 study patients. A contrast agent was used to obtain adequate Doppler signals in 29 patients. Of the 105 patients, there were 18 patients with abnormal perfusion (group A) and 87 patients with normal perfusion (group B) in the LAD territories on Tl-201 SPECT. CFVR was greater in group B than in group A (1.7 +/- 0.5 vs. 3.7 +/- 0.8, P < 0.0001, respectively). There were 17 patients with CFVR < 2 and 88 patients with CFVR > or = 2. CFVR < 2 predicted restenosis determined by Tl-201 SPECT, with a sensitivity of 94% and a specificity of 100%.

CONCLUSIONS

Noninvasive measurement of CFVR by TTDE accurately reflects the physiological severity of coronary narrowing due to restenosis after PCI. This method has possibility of reducing the number of unnecessary coronary angiographies after PCI.