Characteristics of IVUS and CAG in the patients with unstable angina with angiographic mild coronary stenosis

Objective To investigate the characteristics of lesion of angiographic mild coronary stenosis using intravascular ultrasound(IVUS) and coronary angiography(CAG) in patients with unstable angina.Methods Forty-two coronary artery segments with mild stenosis found by CAG in 30 patients were examined by IVUS to analyze the characteristics of the plaques.The morphology and severity of stenoses measured by the two techniques were compared.Results Twenty-six eccentric stenoses and 16 concentric ones were found by CAG;34 eccentric plaques,8 concentric plaques and 28 vulnerable plaques were detected by IVUS.There was significant difference in stenosis rate of the diameters at the narrowest sites of the stenosed vessels between CAG and IVUS [(29.06±7.20)%vs(37.37±6.50)%,P0.05].The area stenosis rate determined by IVUS was(41.51±7.50)%.Conclusion The CAG underestimates the intravascular lesion of coronary artery,while IVUS can identify it accurately.