ABSTRACT
Objective To identify the causes of coronary angiographic hazy lesions by intravascular ultrasound (IVUS) to avoid inappropriate stenting. Methods Twenty-five cases with hazy regions on coronary angiogram were consecutively identified from July 2009 to March 2010. Hazy regions were defined by coronary arteriongraphy as reduced contrast density without a clearly defined intimal tear, dissection,thrombus,or stenosis ( ＞ 50% ). This cohort of patients were subsequently underwent IVUS examinations and treated according to the results of IVUS. Results The lumen CSAs were settled as ＞ 4. 0 mm2 in all examinations. Among all 25 cases,hazy lesions were located in left anterior descending in 12 patients, right coronary artery in 6 patients, left circumflex in 5 patients, and left main artery in 2 patients. According to the IVUS findings, 2 cases showed absolutely normal or near-normal arterial wall structure image, 10 cases showed calcified plaque,5 cases showed plaque rupture,3 cases showed eccentric plaque ,2 cases showed thrombosis formation,2cases showed dissection,1 case showed subintimal hematoma. Seven patients received stent implantation, and the rest accepted medical therapy. There were no in-hospital MACEs reported among all patients. Conclusion Nearly half of the coronary arteriongraphic hazy lesions were caused by calcified plaque. IVUS can distinguish calcified plaques from intimal tears, thrombus and other underlying etiologies,and help to avoid unnecessary stenting.