Value of acceleration flow and the prestenotic to stenotic coronary flow velocity ratio by transthoracic color doppler echocardiography in noninvasive diagnosis of restenosis after percutaneous transluminal coronary angioplasty

OBJECTIVES The study evaluated the value of coronary flow velocity measurement by transthoracic color Doppler echocardiography (TTCDE) for the noninvasive diagnosis of restenosis after percutaneous transluminal coronary angioplasty (PTCA) for left anterior descending coronary artery (LAD) lesions. BACKGROUND Recent advances in TTCDE provide coronary flow velocity measurements in the LAD under the guidance of color flow mapping. METHODS We studied 53 patients who underwent successful PTCA for LAD lesions and follow-up coronary angiography (18 patients with restenosis [Group-R], 35 patients without restenosis [Group-N]). We searched localized color aliasing corresponding to local flow acceleration to obtain coronary flow velocity at PTCA sites in the LAD. When localized aliasing was detected, we measured coronary flow velocity at the aliasing (stenotic site) and the prestenotic site. RESULTS Using TTCDE, it was possible to measure mean diastolic velocity (MDV) in the LAD in 41 (77%) of 53 patients (14 of 18 patients in Group-R; 27 of 35 patients in Group-N). Localized aliasing was displayed by color flow mapping in 14 (100%) of 14 patients in Group-R, and 15 (56%) of 27 patients in Group-N. Stenotic MDV in Group-R was significantly higher than that in Group-N (60.3 ± 21.1 vs. 35.1 ± 7.6 cm/s, p < 0.01), although prestenotic MDV did not differ between Group-R and Group-N (20.2 ± 3.0 vs. 19.6 ± 2.3 cm/s). There were significant differences in the prestenotic to stenotic MDV ratio between Group-R and Group-N (0.36 ± 0.10 vs. 0.57 ± 0.09, p < 0.001). Localized aliasing with the prestenotic to stenotic MDV ratio <0.45 as the optimal cutoff value had a sensitivity of 86% and a specificity of 93% for the presence of restenosis in LAD lesions. CONCLUSIONS Detection of localized color aliasing and measurement of the prestenotic to stenotic MDV ratio in the LAD by TTCDE are useful in the noninvasive diagnosis of restenosis after PTCA for LAD lesions.