INTRACORONARY DOPPLER ASSESSMENT OF MODERATE CORONARY-ARTERY DISEASE - COMPARISON WITH TL-201 IMAGING AND CORONARY ANGIOGRAPHY

Background Coronary angiography may not reliably predict whether a ste nosis causes exercise-induced ischemia. Intracoronary Doppler ultrasou nd may enhance diagnostic accuracy by providing a physiological assess ment of stenosis severity. The goal of this study was to compare intra coronary Doppler ultrasound with both Tl-201 imaging and coronary angi ography. Methods and Results Fifty-five patients with 67 stenotic coro nary arteries underwent coronary angiography with intracoronary Dopple r ultrasound and had exercise Tl-201 testing within a 1-week period. C oronary flow reserve was measured, and analyses were performed by inde pendent core laboratories. The mean stenosis was 59+/-12%; 51 of 67 st enoses were intermediate in severity (40% to 70%). A coronary flow res erve <1.7 predicted the presence of a stress Tl-201 defect in 56 of 67 stenoses (agreement=84%; kappa=0.67; 95% CI=0.48 to 0.86). In the pat ients who achieved 75% of their predicted maximum heart rate, the Dopp ler and Tl-201 imaging data agreed in 46 of 52 stenoses (agreement=88% ; kappa=0.77; 95%CI=0.57 to 0.97). Scatter was evident when angiograph y was compared with coronary flow reserve (r=.43), and the angiogram d id not reliably predict the results of the Tl-201 stress test (kappa-0 .21; agreement=57% to 63%). Conclusions Doppler-derived coronary flow reserve accurately predicts the presence of exercise-induced ischemia on stress Tl-201 imaging, and coronary angiography does not reliably a ssess the physiological significance of an intermediate coronary steno sis.