Intravascular ultrasound study of angiographically mildly diseased coronary arteries

Objective:To evaluate the effect of intravascular ultrasound imagingon the diagnosis of coronary artery disease (CAD).Method:The study involved 104 patients with CAD or snspected CAD. 73 men and 31 women, aged 36～77 years ( 61.68 ± 9.98 years). Electrocardiography, Echocardiography, coronary angiogram (CAG) and Intravascular ultrasound imaging (IVUS) were taken. The findings of CAG and IVUS were compared by chi square analysis and test and correlations.Result: A total of 113 vesseles segments in 104 patients were studied. Mean maximal arterial area narrowing measured by IVUS was( 74.00 ± 14.91 )% (rang 0% to 92.34 %), compared with that by quantitative anglography ( 58.07 ± 17.42 )%(rang 0～ 85.12 %, P 0.05 ). The mean length was( 21.16 ± 25.17 mm by ultrasound, and ( 14.12 ± 10.08 )mm by guantitative angiography (P 0.05 ).Angiography detected calcium plaques in 8 of 113 lesions, and IVUS detected calcium plaques in 47 of 113 (P 0.01 ). There were eccentric plaques in 13 of 113 lesions by angiogrphy, and in 73 of 113 lesions by ultrasound (P 0.01 ). Conclusion:There is a significant understimantion of mildly diseased coronary arteries by quantitative angiography. The false negative rate is 8%. If patients with angina associate with normal CAG, should take IVUS.