Application Of Intravascular Ultrasound In Assessing Borderline Coronary Artery Disease

AimsTo identify the difference between patients with acute coronary syndrome and patients with non-acute coronary syndrome by intravascular ultrasound in borderline coronary artery disease. To investigate the relationship between serum uric acid (SUA) and cardiovascular plaque components in borderline coronary artery disease by intravascular ultrasound (IVUS).MethodsBetween December 2007 and April 2010,114 consecutive patients who had lesions of intermediate severity (40%-70% diameter stenosis) in coronary angiography (CAG) were enrolled in the Cardiac Catheterization Laboratory of Zhongshan Hospital, Fudan University. The baseline clinical characteristics were collected. All of patients underwent quantitative coronary angiography (QCA) and IVUS assessment of the lesions artery. We conducted the follow-up of major adverse cardiovascular events (MACE).Results1. According to clinical characteristics, ECG change, cardiac enzymes and cTnT,114 patients were divided into two groups. One was ACS group (50 patients), the other was non-ACS group (64 patients). It was shown that sex, smoking, blood white cells and triglycerides was higher but family history was lower in ACS group. The other clinical characteristics and QCA had no significantly difference in both groups. IVUS found that the proportion of soft plaque was higher but fibrous plaque was lower in ACS group. Plaque rupture was found in 10 patients:non-ACS group 3 (4.7%) and ACS group 7(14.0%).2 cases presented thrombosis in ACS group, there was no difference between two groups in minimal lumen area (MLA), plaque burden (PB), the proportion of eccentric plaque and positive remodeling.57 of 114 cases carried on PCI:non-ACS group 24 and ACS group 33. 9 of 10 patients with plaque rupture underwent PCI. The stent size was up to the reference segment diameter and length by IVUS and all of cases were operation successful. No MACE was found during hospitalization.13 cases failed to be followed up. Symptoms were significantly improved in most of patients.4 of non-ACS group and 4 of ACS group recurred Angina pectoris. Only 1 case in ACS group has cardiac death.2.114 patients were explored cardiovascular plaque composition by IVUS and taken SUA of measurement According to American Heart Association IVUS criterion, coronary artery plaque was divided into four categories:(1) Soft plaque; (2) Fibrous plaque; (3) Calcified plaque; (4) Mixed plaque. It was shown that the level of SUA in calcified plaque group was significantly higher than other three groups (P=0.021), there was no significant difference between other three of them.All of patients were further divided into two groups:calcified plaque and non-calcified plaque. There was no difference between two groups in the proportion of ACS patients (P=0.957).57 of 114 cases carried on PCI. The stent size was up to the reference segment diameter and length by IVUS and all of cases were operation successful. No MACE was found during hospitalization. The proportion of intervention therapy and short-term follow-up results were not different between tow groups.Conclusion1. The proportion of soft plaque was higher but fibrous plaque was lower in ACS group. There was no difference between two groups in minimal lumen area (MLA), plaque burden (PB), the proportion of eccentric plaque and Positive remodeling. These results indicated that the property of plaque played a central role in contributing to acute coronary events.2. Through the proportion of intervening therapy was obviously higher in ACS group, the following-up showed the incidence of MACE was of no statistical difference in the two groups. It indicated that it was of great significance for the patients with borderline coronary artery disease to judge and assess the lesions better by IVUS and then choose the optimal therapy strategies.3. The present study found that hyperuricemia was relevant to the development of calcified plaque and may help to judge the stability of plaques.