Effects of 6-month eicosapentaenoic acid treatment on postprandial hyperglycemia, hyperlipidemia, insulin secretion ability, and concomitant endothelial dysfunction among newly-diagnosed impaired glucose metabolism patients with coronary artery disease. An open label, single blinded, prospective randomized controlled trial.

BACKGROUND: Recent experimental studies have revealed that n-3 fatty acids, such as eicosapentaenoic acid (EPA) regulate postprandial insulin secretion, and correct postprandial glucose and lipid abnormalities. However, the effects of 6-month EPA treatment on postprandial hyperglycemia and hyperlipidemia, insulin secretion, and concomitant endothelial dysfunction remain unknown in patients with impaired glucose metabolism (IGM) and coronary artery disease (CAD). METHODS AND RESULTS: We randomized 107 newly diagnosed IGM patients with CAD to receive either 1800 mg/day of EPA (EPA group, n = 53) or no EPA (n = 54). Cookie meal testing (carbohydrates: 75 g, fat: 28.5 g) and endothelial function testing using fasting-state flow-mediated dilatation (FMD) were performed before and after 6 months of treatment. The primary outcome of this study was changes in postprandial glycemic and triglyceridemic control and secondary outcomes were improvement of insulin secretion and endothelial dysfunction. After 6 months, the EPA group exhibited significant improvements in EPA/arachidonic acid, fasting triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C). The EPA group also exhibited significant decreases in the incremental TG peak, area under the curve (AUC) for postprandial TG, incremental glucose peak, AUC for postprandial glucose, and improvements in glycometabolism categorization. No significant changes were observed for hemoglobin A1c and fasting plasma glucose levels. The EPA group exhibited a significant increase in AUC-immune reactive insulin/AUC-plasma glucose ratio (which indicates postprandial insulin secretory ability) and significant improvements in FMD. Multiple regression analysis revealed that decreases in the TG/HDL-C ratio and incremental TG peak were independent predictors of FMD improvement in the EPA group. CONCLUSIONS: EPA corrected postprandial hypertriglyceridemia, hyperglycemia and insulin secretion ability. This amelioration of several metabolic abnormalities was accompanied by recovery of concomitant endothelial dysfunction in newly diagnosed IGM patients with CAD. Clinical Trial Registration UMIN Registry number: UMIN000011265 ( https://www.upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&type=summary&recptno=R000013200&language=E ).

Impact of esophageal temperature monitoring guided atrial fibrillation ablation on preventing asymptomatic excessive transmural injury.

BACKGROUND: Even with the use of a reduced energy setting (20-25 W), excessive transmural injury (ETI) following catheter ablation of atrial fibrillation (AF) is reported to develop in 10% of patients. However, the incidence of ETI depends on the pulmonary vein isolation (PVI) method and its esophageal temperature monitor setting. Data comparing the incidence of ETI following AF ablation with and without esophageal temperature monitoring (ETM) are still lacking. METHODS: This study was comprised of 160 patients with AF (54% paroxysmal, mean: 24.0±2.9 kg/m(2)). Eighty patients underwent ablation accompanied by ETM. The primary endpoint was defined as the occurrence of ETI assessed by endoscopy within 5 d after the AF ablation. The secondary endpoint was defined as AF recurrence after a single procedure. If the esophageal temperature probe registered >39 °C, the radiofrequency (RF) application was stopped immediately. RF applications could be performed in a point-by-point manner for a maximum of 20 s and 20 W. ETI was defined as any injury that resulted from AF ablation, including esophageal injury or periesophageal nerve injury (peri-ENI). RESULTS: The incidence of esophageal injury was significantly lower in patients whose AF ablation included ETM compared with patients without ETM (0 [0%] vs. 6 [7.5%], p=0.028), but not the incidence of peri-ENI (2 [2.5%] vs. 3 [3.8%], p=1.0). AF recurrence 12 months after the procedure was similar between the groups (20 [25%] in the ETM group vs. 19 [24%] in the non-ETM group, p=1.00). CONCLUSIONS: Catheter ablation using ETM may reduce the incidence of esophageal injury without increasing the incidence of AF recurrence but not the incidence of peri-ENI.

Efficacy of bilateral thoracoscopic sympathectomy in a patient with catecholaminergic polymorphic ventricular tachycardia.

A 27-year-old woman with frequent implantable cardioverter defibrillator (ICD) shocks related to catecholaminergic polymorphic ventricular tachycardia (VT) experienced aborted sudden death due to incessant polymorphic VT despite the administration of beta-blockers, verapamil, and flecainide. Catheter ablation failed to suppress the polymorphic VT. Based on the temporary efficacy of the local anesthetic administered at the left and right cervical sympathetic nerves to suppress VT under an isoproterenol infusion, stepwise, bilateral thoracoscopic sympathectomy was performed. Postoperatively, no further VT or syncopal episodes were documented under ICD telemetry. Bilateral thoracoscopic sympathectomy may be an alternative for patients with drug-refractory catecholaminergic polymorphic VT.

Usefulness of non-contrast-enhanced MRI with two-dimensional balanced steady-state free precession for the acquisition of the pulmonary venous and left atrial anatomy pre catheter ablation of atrial fibrillation: Comparison with contrast enhanced CT in clinical cases.

BACKGROUND: To investigate the feasibility of substituting non-contrast-enhanced MR (non-CE-MR) imaging with a two-dimensional (2D) balanced steady-state free precession (b-SSFP) sequence for contrast-enhanced computed tomography (CE-CT) for atrial fibrillation (AF) ablation. METHODS: Fifty-four patients that underwent AF ablation under the guidance of a 3D electro-anatomical mapping system with CE-CT (n = 27) or non-CE-MR images (n = 27) were studied. Procedural results were compared between the two groups. Furthermore, in 22 patients who underwent both CE-CT and non-CE-MRI, two cardiologists independently scored the multiplanar reformatted images on a scale of 1 to 4 (from 1, poor, to 4, excellent). RESULTS: The image score was nearly 0.5 point higher with the CE-CT method. However, the procedural results such as the surface registration error (1.0 [0.8-1.6] mm versus 1.0 [0.8-1.35] mm, P = 0.88) and procedure time (185 [159-199] min versus 185 [142-221] min, P = 0.86) did not significantly differ between the CE-CT and non-CE-MR groups. CONCLUSION: The non-CE-MR method with a 2D-b-SSFP sequence can give us adequate information on AF ablation without any radiation exposure or contrast medium usage

A case of inappropriate implantable cardioverter defibrillator therapy induced by T-wave oversensing due to hyperkalemia.

There have been reports of hyperkalemia-induced T-wave oversensing in patients with implantable cardioverter defibrillators (ICDs). However, a comparison of T-wave amplitudes and morphologies between the surface 12-lead electrocardiogram (ECG) and ICD electrogram has not been reported. We present the case of a 70-year-old man who received inappropriate ICD shocks due to hyperkalemia-induced T-wave oversensing. The T-wave amplitudes on both the ICD electrogram and 12-lead ECG corresponded and normalized after normalization of the potassium level.

Incidence of esophageal injury after pulmonary vein isolation in patients with a low body mass index and esophageal temperature monitoring at a 39 °C setting.

BACKGROUND: Esophageal injury following catheter ablation of atrial fibrillation (AF) is reported to occur in 35% of patients. Even with a low energy setting (20-25 W), lesions develop in 10% of patients. Body mass index (BMI) has been reported to be a predictor of esophageal injury, indicating that patients with a low BMI (<24.9 kg/m(2)) are at a higher risk. We hypothesized that catheter ablation with a lower energy setting of 20 W controlled by esophageal temperature monitoring (ETM) at 39 °C could prevent esophageal injury even in patients with a BMI <24.9 kg/m(2). METHODS: Twenty patients with AF were included (age, 63±8 years; BMI, 22.9±1.3 kg/m(2), left atrium diameter, 44±11 mm). If the esophageal temperature probe registered a temperature of >39 °C, radiofrequency (RF) application was stopped immediately. RF application could be performed in a "point by point" manner for a maximum of 20 s. Endoscopy was performed 1-5 days after ablation. RESULTS: Esophageal mucosal injury was not observed in any patient in the study. CONCLUSIONS: Catheter ablation using ETM reduced the incidence of esophageal injuries, even in patients with a low BMI.

Visualizing radiofrequency lesions using delayed-enhancement magnetic resonance imaging in patients with atrial fibrillation: A modification of the method used by the University of Utah group.

BACKGROUND: Atrial tissue fibrosis has previously been identified using delayed-enhancement MRI (DE-MRI) in patients with atrial fibrillation (AF). Although the clinical importance of DE-MRI is well recognized, the visualization of atrial fibrosis and radiofrequency (RF) lesions has still not been achieved in Japan, primarily because of the differences in contrast agents, volume-rendering tools, and technical experience. The objective of this study was to visualize RF lesions by using commercially available tools. METHODS: DE-MRI was performed in 15 patients who had undergone AF ablation (age, 59±4 years, left atrium diameter, 40±2 mm). Specific parameters for MR scanning obtained from previous reports were modified. RESULTS: Of the 15 images, the images of three patients were uninterpretable owing to low image quality. RF lesions could be visualized in 8 (67%) of the 12 patients. CONCLUSIONS: In the current study, we successfully demonstrated that RF lesions could be visualized in Japanese patients using DE-MRI, although only commercially available tools were used.

Visualization of the radiofrequency lesion after pulmonary vein isolation using delayed enhancement magnetic resonance imaging fused with magnetic resonance angiography.

BACKGROUND: The radiofrequency (RF) lesions for atrial fibrillation (AF) ablation can be visualized by delayed enhancement magnetic resonance imaging (DE-MRI). However, the quality of anatomical information provided by DE-MRI is not adequate due to its spatial resolution. In contrast, magnetic resonance angiography (MRA) provides similar information regarding the left atrium (LA) and pulmonary veins (PVs) as computed tomography angiography. We hypothesized that DE-MRI fused with MRA will compensate for the inadequate image quality provided by DE-MRI. METHODS: DE-MRI and MRA were performed in 18 patients who underwent AF ablation (age, 60±9 years; LA diameter, 42±6 mm). Two observers independently assessed the DE-MRI and DE-MRI fused with MRA for visualization of the RF lesion (score 0-2; where 0: not visualized and 2: excellent in all 14 segments of the circular RF lesion). RESULTS: DE-MRI fused with MRA was successfully performed in all patients. The image quality score was significantly higher in DE-MRI fused with MRA compared to DE-MRI alone (observer 1: 22 (18, 25) vs 28 (28, 28), p<0.001; observer 2: 24 (23, 25) vs 28 (28, 28), p<0.001). CONCLUSIONS: DE-MRI fused with MRA was superior to DE-MRI for visualization of the RF lesion owing to the precise information on LA and PV anatomy provided by DE-MRI.

Acquisition of the pulmonary venous and left atrial anatomy with non-contrast-enhanced MRI for catheter ablation of atrial fibrillation: Usefulness of two-dimensional balanced steady-state free precession.

BACKGROUND: Usually, the pulmonary venous and left atrial (PV-LA) anatomy is assessed with contrast-enhanced computed tomographic imaging for catheter ablation of atrial fibrillation (AF). A non-contrast-enhanced magnetic resonance (MR) imaging method has not been established. Three-dimensional balanced steady-state free precession (3D b-SSFP) sequences cannot visualize the PV-LA anatomy simultaneously because of the signal intensity defect of pulmonary veins. We compared two-dimensional (2D) b-SSFP sequences with 3D b-SSFP sequences in depicting the PV-LA anatomy with non-contrast-enhanced MR imaging for AF ablation. METHODS: Eleven healthy volunteers underwent non-contrast-enhanced MR imaging with 3D b-SSFP and 2D b-SSFP sequences. The MR images were reconstructed on the 3D PV-LA surface image. Two experienced radiological technicians independently scored the multiplanar reformatted (MPR) images on a scale of 1-4 (from 1, not visualized, to 4, excellent definition). The overall score was a sum of 5 segments (LA and 4 PVs). RESULTS: In the 2D b-SSFP method, MR imaging was successfully performed, and the 3D PV-LA surface image was precisely reconstructed in all healthy volunteers. The image score was significantly higher in the 2D b-SSFP method compared to the 3D b-SSFP method (19 [19; 20] vs. 12 [11; 15], p=0.004, for both observers). No PV signal intensity defects occurred in the 2D b-SSFP method. CONCLUSIONS: The 2D b-SSFP sequence was more useful than the 3D b-SSFP sequence in adequately depicting the PV-LA anatomy.

Coexistence of persistent left superior vena cava with common inferior pulmonary vein in a patient with atrial fibrillation.

Coexistence of a persistent left superior vena cava (PLSVC) with a common inferior pulmonary vein (CIPV) is very rare. The electrical assessment of those thoracic veins was performed during the atrial fibrillation ablation.

Novel Compression Tool to Prevent Hematomas and Skin Erosions After Device Implantation.

BACKGROUND: The incidence of hematoma formation following implantation of a cardiovascular implantable electronic device (CIED) is estimated to be 5% even if a pressure dressing is applied. It is unclear whether a pressure dressing can really compress the pocket in different positions. Furthermore, the adhesive tape for fixing pressure dressings can tear the skin. We developed a new compression tool for preventing hematomas and skin erosions. METHODS AND RESULTS: We divided 46 consecutive patients receiving anticoagulation therapy who underwent CIED implantation into 2 groups (Group I: conventional pressure dressing, Group II: new compression tool). The pressure on the pocket was measured in both the supine and standing positions. The incidence of hematomas was compared between the 2 groups. The pressure differed between the supine and standing positions in Group I, but not in Group II (Group I: 14.8±7.1 mmHg vs. 11.3±9.9 mmHg, P=0.013; Group II: 13.5±2.8 mmHg vs. 13.5±3.5 mmHg, P=0.99). The incidence of hematomas and skin erosions was documented in 2 (8.7%) and 3 (13%) Group I patients, respectively. No complications were documented in Group II. CONCLUSIONS: The new compression tool can provide adequate continuous pressure on the pocket, regardless of body position. This device may reduce the incidence of hematomas and skin erosions after CIED implantation.

Comparison of tissue characteristics between acute coronary syndrome and stable angina pectoris. An integrated backscatter intravascular ultrasound analysis of culprit and non-culprit lesions.

BACKGROUND: Patients with acute coronary syndrome (ACS) have multiple complex coronary plaques associated with plaque vulnerability. The present study assessed the tissue characteristics of coronary plaques between ACS and stable angina pectoris (SAP) of culprit and non-culprit lesions using integrated backscatter intravascular ultrasound (IB-IVUS). METHODS AND RESULTS: IVUS was performed in 165 patients (40 patients with ACS) with 225 culprit (65 lesions in ACS) and 171 non-culprit lesions (42 lesions in ACS). The percentage of fibrous area (fibrous area/plaque area, %FIB) and the percentage of lipid area (lipid area/plaque area, %LIP) at the segment with minimal luminal area were calculated using IB-IVUS system. Culprit and non-culprit lesions with ACS showed a significant increase in %LIP (38±18 vs. 30±15%, P=0.002, and 38±21 vs. 32±17%, P=0.03, respectively) and a significant decrease in %FIB (59±15 vs. 63±12 %, P=0.04, and 57±18 vs. 62±14%, P=0.04, respectively) compared to those with SAP. On logistic regression analysis, not only culprit lesions but also non-culprit lesions with ACS patients were significantly associated with the lipid-rich plaque. CONCLUSIONS: Non-culprit coronary lesions with ACS patients are associated with the lipid-rich plaque, suggesting the extensive development of plaques instability in these patients.

Volumetric analysis of coronary plaque characterization in patients with metabolic syndrome using 64-slice multi-detector computed tomography.

BACKGROUND: Metabolic syndrome (MetS) is associated with adverse cardiovascular events and mortality, where acute coronary syndrome significantly impacts on mortality and morbidity. In contrast, evidences have accumulated that the lipid-rich plaque might play a critical role in acute coronary syndrome. METHODS AND RESULTS: The study population consisted of 94 patients with suspected angina pectoris who underwent multi-detector computed tomography (MDCT). Of those, we identified 41 with MetS. In MDCT analysis, low-density plaque volume (LDPV) (42 ± 28 vs 24 ± 18 mm(3), P=0.0003), moderate-density plaque volume (105 ± 41 vs 82 ± 33 mm(3), P=0.003), total plaque volume (164 ± 70 vs 118 ± 59 mm(3), P=0.0008) and %LDPV (24.2 ± 10.0 vs 18.3 ± 7.1%, P=0.01) were significantly increased in the MetS group compared to the non-MetS group. Multivariate linear regression analysis after adjusting for confounding variables revealed that MetS was significantly correlated with an increase in %LDPV (ß=0.48, P=0.0001). Multivariate logistic regression analysis for lipid-rich plaque after adjusting for confounding variables indicated that MetS was significantly associated with lipid-rich plaque (odds ratio: 5.99, 95% confidence intervals: 1.94-18.6, P=0.002). CONCLUSIONS: Patients with MetS were strongly related to having a lipid-rich composition in their coronary plaque, as detected by MDCT.

The association between plaque characterization by CT angiography and post-procedural myocardial infarction in patients with elective stent implantation.

OBJECTIVES: This study sought to evaluate the association between volumetric characterization of target lesions by multidetector computed tomography (MDCT) angiography and the risk of post-procedural myocardial injury after elective stent implantation. BACKGROUND: Previous reports have shown that plaque characterization of the target lesion may provide useful information for stratifying the risk of coronary stenting. METHODS: A total of 189 consecutive patients were enrolled; they underwent elective stent implantation after volumetric plaque analysis with 64-slice MDCT. Each plaque component and lumen (filled with dye) was defined as follows: 1) low-attenuation plaque (LAP) (<50 HU); 2) moderate-attenuation plaque (MAP) (50 to 150 HU); 3) lumen (151 to 500 HU); and 4) high-attenuation plaque (HAP) (>500 HU). The volume of each plaque component in the target lesion was calculated using Color Code Plaque. Post-procedural creatine kinase-MB isoform and troponin-T (TnT) at 18 h after percutaneous coronary intervention were also evaluated. RESULTS: The volumes of LAP (87.9+/-94.8 mm3 vs. 47.4+/-43.7 mm3, p<0.01) and MAP (111.6+/-77.5 mm3 vs. 89.8+/-67.1 mm3, p<0.05) were larger in patients with post-procedural myocardial injury (defined as positive TnT) than in those with negative TnT. The volumes of LAP and MAP and fraction of LAP in total plaque (LAP volume/total plaque volume) correlated with biomarkers; the MAP fraction was inversely correlated with biomarkers. The volume of LAP was an independent predictor of positive TnT after adjusting for patient background, conventional IVUS parameters, and procedural factors. CONCLUSIONS: Post-procedural myocardial injury was associated with the volume and fraction of LAP as detected by MDCT. The volume of LAP was an independent predictor of positive TnT. Plaque analysis by MDCT would be a useful method for predicting post-procedural myocardial injury after percutaneous coronary intervention.

Intracoronary electrocardiogram recording with a bare-wire system: perioperative ST-segment elevation in the intracoronary electrocardiogram is associated with myocardial injury after elective coronary stent implantation.

OBJECTIVES: With an intracoronary electrocardiogram (IcECG) recording with insulated polymer-coated guidewire without balloon catheter, we sought to examine the association between ST-segment elevation in the IcECG after elective stenting and myocardial injury. BACKGROUND: An IcECG is a sensitive method to detect local myocardial ischemia. Occasionally, persistent ST-segment elevation in the IcECG was recorded after successful coronary intervention. Conventionally IcECG was recorded with a guidewire and over-the-wire system. METHODS: Patients who underwent elective stenting were enrolled (n = 339). The IcECG both at baseline and after procedure were obtained with a guidewire with an insulating coated shaft suitable for IcECG recording. The presence of chest pain after percutaneous coronary intervention was recorded. Cardiac biomarkers were examined 18 h after the procedure. RESULTS: The ST-segment elevation in the IcECG after procedure was recorded in 65 patients, and no change was recorded in 274 patients. Troponin-T, creatine phosphokinase, and creatine kinase MB isoform after the procedure were significantly higher in patients with post-procedural ST-segment elevation in the IcECG than patients without ST-segment elevation. Multivariate analysis demonstrated that ST-segment elevation in the IcECG is an independent predictor of post-procedural myocardial injury. The incidence of ST-segment elevation in the IcECG was significantly higher in patients with post-procedural chest pain than patients without chest pain (p < 0.001). CONCLUSIONS: We demonstrated a facile method to record IcECG with a guidewire with a polymer-coated shaft. The IcECG is a useful method for predicting post-procedural myocardial injuries.

The correlation between lipid volume in the target lesion, measured by integrated backscatter intravascular ultrasound, and post-procedural myocardial infarction in patients with elective stent implantation.

AIMS: The aim of this study was to perform quantitative analysis of the plaques of target lesions by integrated backscatter intravascular ultrasound (IB-IVUS) and to investigate the association between these data and the risk of post-procedural myocardial injury after stenting. METHODS AND RESULTS: One hundred and fourteen consecutive patients who received elective stent implantations following IB-IVUS analysis were enrolled. The volume of each plaque component (lipid, fibrous, and calcified) was calculated for the target lesion. Creatine kinase-MB (CK-MB) and troponin-T (TnT) were also evaluated 18 h after procedure. We defined a post-procedural TnT level higher than three times the normal limit as a post-procedural myocardial injury. Lipid, fibrous, and calcified volumes were greater in patients with myocardial injury than in those without myocardial injury. Lipid and fibrous volumes correlated with post-procedural cardiac biomarkers, and the lipid volume fraction (lipid volume/total plaque volume) also correlated with post-procedural TnT and CK-MB. The fibrous volume fraction for plaques was found to be inversely correlated with post-procedural TnT and CK-MB. Hence, lipid volume and volume fraction were concluded to be independent predictors of post-procedural myocardial injury. CONCLUSION: A larger plaque volume and lipid-rich plaque may be indicative of embolic events after stent implantation, resulting in myocardial injury.

Abnormal glucose regulation is associated with lipid-rich coronary plaque: relationship to insulin resistance.

OBJECTIVES: This study sought to determine lipid and fibrous volume of coronary atherosclerotic plaques in subjects with abnormal glucose regulation (AGR) by integrated backscatter (IB) intravascular ultrasound (IVUS) during percutaneous coronary intervention. BACKGROUND: Abnormal glucose regulation, including impaired glucose regulation (IGR) and diabetes mellitus (DM), has emerged as an important determinant of cardiovascular risk. We hypothesized that AGR would be associated with coronary plaque instability. METHODS: Conventional intravascular ultrasound and IB-IVUS using a 40-MHz (motorized pullback 1 mm/s) intravascular catheter was performed in 172 consecutive patients. The percentage of fibrous area and the percentage of lipid area were automatically calculated by IB-IVUS. Three-dimensional analysis of IB-IVUS images was performed to determine the percentage of lipid volume (%LV) and fibrous volume (%FV). Following the World Health Organization criteria, the subjects were classified into the DM group, the IGR group, and the normal glucose regulation group. The cutoff point for the lipid-rich plaque was defined as %LV >44% or %FV <52%, which was the 75th percentile of %LV or the 25th percentile of %FV in this study population. Insulin resistance (IR) was defined as the homeostasis model assessment of insulin resistance (HOMA-IR). RESULTS: There were no significant differences in the baseline characteristics except for glucometabolic parameters. The conventional IVUS analysis indicated that the DM group had a significantly increased plaque volume (and percent plaque volume). In the IB-IVUS analysis, as compared with the normal glucose regulation group, the DM and the IGR groups showed a significant increase in %LV (36 +/- 14% and 37 +/- 13% vs. 29 +/- 14%, p = 0.02) and a significant decrease in %FV (59 +/- 11% and 58 +/- 11% vs. 64 +/- 11%, p = 0.03). The lipid-rich plaque rate was significantly associated with an increasing HOMA-IR in the tertile (p = 0.008). On logistic regression analysis after adjusting for confounding and coronary risk factors, the DM group (odds ratio 3.52, 95% confidence interval 1.13 to 11.0, p = 0.03) and the IGR group (odds ratio 3.92, 95% confidence interval 1.13 to 13.6, p = 0.03) were significantly associated with the lipid-rich plaque. CONCLUSIONS: Coronary lesions in patients with AGR are associated with more lipid-rich plaque content, which may be related to the increased IR in these patients.

Impact of metabolic syndrome on tissue characteristics of angiographically mild to moderate coronary lesions integrated backscatter intravascular ultrasound study.

OBJECTIVES: We assessed the impact of metabolic syndrome (MetS) on the tissue characteristics of coronary plaques using integrated backscatter intravascular ultrasound (IB-IVUS). BACKGROUND: Metabolic syndrome is associated with the increasing risk of cardiovascular disease. METHODS: We identified MetS by the definition of the National Cholesterol Education Program in Adult Treatment Panel III criterion. Non-target coronary lesions with mild to moderate stenosis were measured by conventional and IB-IVUS parameters using 40-MHz (motorized pullback 0.5 mm/s) intravascular catheter. A total of 20 IB-IVUS images were recorded at an interval of 0.5 mm for 10 mm length in each plaque. The 3-dimensional analyses were performed using commercially available software. RESULTS: The prevalence of MetS was 61 patients (50%) with 73 lesions (49%) among 122 patients with 148 lesions. Patients with MetS showed a significant increase in percentage lipid area (38 +/- 19% vs. 30 +/- 19%, p = 0.02) and percentage lipid volume (39 +/- 17% vs. 33 +/- 17%, p = 0.03), and they also showed a significant decrease in percentage of fibrous volume (57 +/- 14% vs. 61 +/- 13%, p = 0.03). Multivariate regression analysis after adjustment for potentially confounding risk factors showed that MetS remains correlated independently with the percentage of lipid volume (r = 0.223, p = 0.01). Logistic regression analysis after adjusting for confounding and non-MetS coronary risk factors showed that MetS (odds ratio 4.00, 95% confidence interval 1.33 to 12.0, p = 0.01) is proved to be an independent predictor of the lipid-rich plaque. CONCLUSIONS: Metabolic syndrome is associated with lipid-rich plaques, contributing to the increasing risk of plaque vulnerability.