Coronary plaque characterization of nonculprit or nontarget lesions assessed by analysis of in vivo intracoronary ultrasound radio-frequency data

Background Unheralded sudden death and acute myocardial infarction are common manifestations of coronary atherosclerosis. Such events are related to thrombotic occlusion at the site of non-flow limiting atherosclerotic plaques in epicardial coronary arteries. This study aimed to assess plaque characterization of nonculprit lesions in patients with acute coronary syndrome （ACS） compared with those with stable angina pectoris （SAP） determined by analysis of intravascular ultrasound （IVUS） radiofrequency （RF） data. Methods In 81 patients, nonculprit vessels with 〈50% diameter stenosis and nontarget segment of culprit vessels with 〈50% diameter stenosis were studied with IVUS. Tissue maps were reconstructed from RF data using IVUS-Virtual Histology software. Results Mean lipid core percentage was significantly higher in patients with ACS than in those with SAP （（25.78±6.30）% vs （9.11±4.90）%, P 〈0.001）. In addition, patients with SAP showed more fibrotic vessels （（59.66±16.87）% vs （49.07±10.20）%, P 〈0.001）. There was no significant difference in either mean calcium （（4.37±2.40）% vs （5.12±3.00）%, P=-0.225） or fibrolipid （（24.94±9.40）% vs （25.82±13.60）%, P=0.731） percentages in nonculprit vessels, but the mean calcium percentage was significantly higher in nontarget lesions of culprit vessels （（5.51±3.29）% vs （3.57±2.10）%, P=0.003）. In addition, there was a positive correlation between lipid core and remodeling index （RI） （r=0.847, P〈0.001） and a negative correlation between fibrous tissue and RI （r= -0.946, P〈0.001）. Conclusions In this study, in both nonculprit vessels and nontarget lesion of culprit vessels, plaque characterization of nonculprit lesions determined by spectral analysis of IVUS RF data was significantly different in patients with ACS. The percentage of lipid core was significantly higher in patients with ACS than in those with SAP. Conversely, SAP patients showed more fibrotic content. In vivo plaque composition and morphological changes were related to remodeling of the coronary artery tree.

Intracoronary stent implantation under intracoronary ultrasound guidance with aspirin and ticlopidine therapy

Objective To observe the immediate angiographic and intravascular ultrasound (IVUS) results and their effects on one month clinical outcomes in forty one patients who submitted to coronary stent deployment with IVUS guidance Methods All patients were allocated to coronary stent implantation with high inflation pressure After good angiographic results (<20% residual stenosis), all patients underwent IVUS and higher pressure dilatation would be necessary if criteria for optimal coronary stent implantation were not met The optimal criterion of IVUS for stent implantation was the ratio of intrastent lumen cross sectional area to the average of the proximal and distal reference lumen cross sectional areas ≥80% All patients had aspirin and ticlopidine therapy on the day of angioplasty and during the one month follow up period Results Optimal criteria of IVUS were obtained without any further intrastent dilatation in twenty five patients but intrastent higher pressure dilatation was performed in fourteen patients whose ultrasound results did not reach the criteria In these patients, we increased the minimal intrastent lumen area 25 7% ( P <0 05) Thirty five patients (90%) had good minimal intrastent lumen area of IVUS There were no deaths, myocardial infarction, acute stent thrombosis or need for revascularization during the study and the one month follow up Conclusions Intracoronary stent deployment under IVUS guidance, including combining aspirin and ticlopidine therapy, had beneficial ultrasound results and good clinical outcomes after one month follow up

Assessment of angiographic coronary slow flow phenomenon with intracoronary ultrasound and doppler flow mapping

In order to study the mechanism of angiographic coronary slow flow phenomenon (SF), intracoronary ultrasound (ICUS) and Doppler (ICD) were performed in 14 patients with angiographic SF phenomenon but with normal angiograms and in 16 patients with normal angiographic coronary flow (NF). A 3.5 F, 20 MHz ultrasound catheter (Boston Scientific) was used for ICUS and a 0.014 inch FloWire (Cardiometrics) was used for ICD. Coronary flow velocity including average peak velocity (APV), maximal peak velocity (MPV) at rest and at hyperemia as well as coronary flow reserve (CFR) were compared in both groups in comparison to the presence or absence of plaque formation based on ICUS. CFR in the SF group (4.2±1.1) was even higher than that of the NF group (3.1±0.6, P<0.001). Department of Cardiology, University GHS Essen, Germany (Ge JB, Simon H, Jeremias A, Liu FQ, Grge G, Haude M, Baumgart D and Erbel R) Significant differences were also found concerning the APV and MPV among both groups (both P <0.001). Plaque formation was found in 7/13 patients with a lumen reduction of 21%±24% in SF group and in 7/16 of the NF group with a lumen reduction of 19%±17%. Comparison of APV, MPV and CFR in SF and NF grups. Comparison of APV, MPV and CFR in SF and NF groups[BHDFG1*2,WK8ZQ1,WK11DW,WK11DWW] SF group NF groupAPV (cm/s) Rest 7.7±2.0 21.1±5.0 * Peak31.7±14.961.3±14.2 *MPV (cm/s) Rest17.4±4.637.0±11.4 * Peak56.8±14.981.8±17.7 *CFR4.2±1.13.1±0.6 # * P<0.001, #P=0.002. Coronary slow flow phenomenon in angiography indicates reduced resting flow velocity without reduction of coronary flow reserve.