RELATION BETWEEN SINGLE TOMOGRAPHIC INTRAVASCULAR ULTRASOUND IMAGE PARAMETERS AND INTRACORONARY DOPPLER FLOW VELOCITY IN PATIENTS WITH INTERMEDIATELY SEVERE CORONARY STENOSES

Background Intravascular ultrasound (IVUS) imaging parameters have bee n suggested as criteria to determine coronary lesion significance befo re intervention. However, there hers not been a systematic examination of combined anatomic and physiologic data in the same patients with c oronary artery disease. Methods and Results To examine the relation be tween coronary flow reserve and IVUS parameters, 41 patients with inte rmediately severe coronary artery stenoses had measurements of coronar y flow velocity (0.014-inch Doppler flow wire), coronary flow velocity reserve (CVR) (hyperemic/basal mean flow), IVUS imaging (2.9F, Cardio vascular Imaging Systems, Inc.), and quantitative coronary angiography before intervention. Correlations between physiologic and anatomic pa rameters were performed by simple regression. Results were also examin ed by patient subgroups with CVR >1.8 or <1.8 to assess differences in IVUS parameters. The angiographic percent diameter stenosis was 52% /- 17% (range 18% to 95%). Mean CVR was 1.88 +/- 0.56 (range 0.9 to 3. 18). IVUS minimal luminal diameter(r = 0.312, p = 0.047) and angiograp hic percent stenosis (r = 3.05, p = 0.052) were weakly related to post stenotic CVR. Comparing patients with CVR <1.8, IVUS reference segment area, IVUS lumen area, and angiographic percent diameter stenosis was higher (17.7 +/- 0.3 vs 12.9 +/- 4.4 mm(2), p < 0.05; 6.20 +/- 3.76 v s 4.34 +/- 2.00 mm(2), p < 0.05; and 60% +/- 14% vs 46% +/- 17%, p < 0 .01, respectively) than in the group with CVR >1.8. Conclusions Despit e a precise determination of cross-sectional vessel areas and absolute dimensions by IVUS, single tomographic measurements did not correlate well with coronary physiologic responses. These data suggest that the physiologic data may be complementary to anatomic quantitative IVUS, enhancing information for coronary interventional decision making.