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The significance of microvessels within atherosclerotic plaques is not yet fully clarified. Associated with plaque vulnerability. The aim of this study is to examine tissue characteristics of plaque with microvessels detected by optical coherence tomography (OCT) by use of a commercially available color-coded intravascular ultrasound (IVUS) and coronary angioscopy (CAS). The subjects examined comprised of 44 patients with stable angina pectoris who underwent percutaneous coronary intervention. Microvessels were defined as a tiny tubule with a diameter of 50-300 µm detected over three or more frames in OCT. We compared the total volume of microvessels with tissue component such as fibrotic, lipidic, necrotic, and calcified volume and the number of yellow plaque. In IVUS analysis, % necrotic volume and % lipidic volume were significantly correlated and % fibrotic volume was inversely significantly correlated with the total volume of microvessel (r = 0.485, p = 0.0009; r = 0.401, p = 0.007; r = - 0.432, p = 0.003, respectively). The number of plaque with an angioscopic yellow grade of two or more was significantly correlated with the total volume of microvessel (r = 0.461, p = 0.002). The greater the luminal volume of microvessels, the more the percent content of necrotic/lipidic tissue volume within plaque and the more the number of yellow plaques. These data suggested that microvessels within coronary plaque might be related to plaque vulnerability.

Dipeptidyl peptidase-4 (DPP-4) inhibitors have potential as a treatment for atherosclerosis. However, it is unclear whether DPP-4 inhibitors stabilize atherosclerotic plaque or alter the composition of complex plaque. Sixteen Watanabe heritable hyperlipidemic rabbits aged 10-12 weeks with atherosclerotic plaque in the brachiocephalic artery detected by iMap ™ intravascular ultrasound (IVUS) were divided into a DPP-4 inhibitor group and a control group. Linagliptin was administered to the DPP-4 inhibitor group via nasogastric tube at a dose of 10 mg/kg/day for 16 weeks, and control rabbits received the same volume of 0.5% hydroxyethylcellulose. After evaluation by IVUS at 16 weeks, the brachiocephalic arteries were harvested for pathological examination. IVUS revealed that linagliptin significantly reduced the plaque volume and vessel volume (control group vs. DPP-4 inhibitor group: ∆plaque volume, 1.02 ± 0.96 mm 3 vs.  - 3.59 ± 0.92 mm 3 , P = 0.004; ∆vessel volume,  - 1.22 ± 2.36 mm 3 vs.  - 8.66 ± 2.33 mm 3 , P = 0.04; %change in plaque volume, 6.90 ± 5.62% vs.  - 15.06 ± 3.29%, P = 0.005). With regard to plaque composition, linagliptin significantly reduced the volume of fibrotic, lipidic, and necrotic plaque (control group vs. DPP-4 inhibitor group: ∆fibrotic volume, 0.56 ± 1.27 mm 3 vs.  - 5.57 ± 1.46 mm 3 , P = 0.04; ∆lipidic volume, 0.24 ± 0.24 mm 3 vs.  - 0.42 ± 0.16 mm 3 P = 0.04; ∆necrotic volume, 0.76 ± 0.54 mm 3 vs.  - 0.84 ± 0.25 mm 3 , P = 0.02). Pathological examination did not show any significant differences in the %smooth muscle cell area or %fibrotic area, but infiltration of macrophages into plaque was reduced by linagliptin treatment (%macrophage area: 12.03% ± 1.51% vs. 7.21 ± 1.65%, P < 0.05). These findings indicate that linagliptin inhibited plaque growth and stabilized plaque in Watanabe heritable hyperlipidemic rabbits.

Aim: To clarify whether the effects of statin treatment on plaque regression vary according to the presence or absence of polyvascular disease (PVD) in patients with acute coronary syndrome (ACS)., Methods: 307 patients with ACS who underwent percutaneous coronary intervention for the culprit lesion at 33 centers were treated with atorvastatin or pitavastatin. Noncoronary atherosclerosis was defined as coexistent, clinically recognized arterial disease other than coronary artery disease (CAD) (cerebral, aortic, or lower extremity). Intravascular ultrasound (IVUS) was performed to assess non-culprit coronary atherosclerosis at baseline and at 8-12 months follow-up. Serial IVUS examinations were obtained in 252 patients. Atheroma volume and percent change in atheroma volume of the target plaque was assessed., Results: Patients of the CAD+PVD (n = 19) were older (68 vs. 62 years, p = 0.02), had lower low-density lipoprotein cholesterol (LDL-C) levels at baseline (116 vs. 134 mg/dL, p=0.03) than those of the CAD-only group (n = 233), whereas LDL-C levels at follow-up were similar (81 vs. 83 mg/dL). Although the baseline plaque volume was similar in the two groups (59 vs. 57 mm(3)), patients of the CAD+PVD group showed milder regression of atherosclerosis than those of the CAD-only group (-8.9% vs. -18.2%, p = 0.005). This difference remained significant even after adjustment for coronary risk factors including age and serum LDL-C (p = 0.047)., Conclusions: Statin treatment results in milder regression of coronary atherosclerosis in CAD patients with polyvascular disease compared to those with CAD only., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Background: There have been few multicenter studies using intravascular ultrasound (IVUS) to assess the process of atherosclerosis in a Japanese population with hypercholesterolemia that is being treated with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors for control of low-density lipoprotein-cholesterol., Methods and Results: An open-label multicenter study is planned to evaluate with IVUS whether treatment with rosuvastatin for 76 weeks results in regression of coronary artery atheroma volume in patients who have coronary heart disease (CHD) and hypercholesterolemia. Sample size is 200 subjects with CHD who are to undergo percutaneous coronary intervention. The planned duration is between October 2005 and October 2008., Conclusions: The COSMOS study will be the first multicenter cardiovascular study in a Japanese population and may provide new evidence on the effects of rosuvastatin on the progression of coronary atherosclerotic lesions.

Objectives: This study theoretically examined the longitudinal structural determinants of plaque vulnerability using a color-coded stress mapping technique for several hypothetical vessel models as well as three-dimensional intravascular ultrasound (IVUS) images with use of a finite element analysis., Background: It has been shown that an excessive concentration of stress is related to atherosclerotic plaque rupture. However, the local determinants of in-plaque longitudinal stress distribution along the coronary arterial wall remain unclear., Methods: Using a finite element analysis, we performed a color mapping of equivalent stress distribution within plaques for three-dimensional vessel models as well as longitudinal IVUS plaque images (n = 15). Then, the effects of plaque size, shape, expansive remodeling, calcification, and lipid core on the equivalent stress distribution were examined., Results: The color mapping of vessel models revealed a concentration of equivalent stress at the top of the hills and the shoulders of homogeneous fibrous plaques. Expansive remodeling and the lipid core augmented the surface equivalent stress, whereas luminal stenosis and superficial calcification attenuated the equivalent stress. The location of excessive stress concentration was modified by the distribution of the lipid core and calcification. The thickness of the fibrous cap was inversely related to the equivalent stress within the fibrous cap. However, the color mapping of IVUS plaque images showed that the equivalent stress value at the fibrous cap varied with changes in plaque shape and superficial calcification, even when the thickness of the fibrous cap remained constant., Conclusions: A distribution analysis of longitudinal stress revealed specific effects of plaque shape, size, and remodeling, as well as effects of the interior distribution of tissue components, on the concentration of stress at the plaque surface. Moreover, fibrous caps of the same thickness did not consistently represent the same vulnerability to rupture.

PURPOSE:To improve the patency rate for angioplasty in chronic occlusion of the superficial femoral artery by deploying stents after angioplasty. MATERIALS AND METHODS:Angioplasty and stent placement were performed in 61 arteries in 48 male patients. The mean occlusion length was 13.5 cm and the mean stent length was 30 cm. Patency rates were analyzed at 6 months and at 1, 2, 3, and 4 years. The predictors of restenosis were analyzed by univariate and multiple logistic regression. RESULTS:Patency rates were 87% at 6 months, consisting of 74% primary, 6% primary assisted, and 7% secondary; 79% at 1 year, consisting of 47% primary, 19% primary assisted, and 13% secondary; 72% at 2 years, consisting of 36% primary, 26% primary assisted, and 10% secondary; 70% at 3 years, consisting of 26% primary, 22% primary assisted, and 22% secondary; and 63% at 4 years, consisting of 25% primary, 0% primary assisted, and 38% secondary. There was a 15% morbidity rate and one mortality as a result of retroperitoneal bleeding. Better patency rates were noted at all time intervals in diabetic limbs, 7-mm-diameter versus 10-mm-diameter stents, shorter obstructions and shorter stents, nonsmokers, in limbs in which urokinase was not necessary after stent deployment, and in limbs with an International Society of Cardiovascular Surgery (ISCVS) classification under 3. Patency rates were not affected by age, race, number of trifurcation vessels patent, experience in performing the procedures, and procedures requiring less time. By multivariate logistic analysis, the independent predictors of patency at 6 months were postprocedure ankle/brachial index (ABI) and shorter stent length; at 1 year, preprocedure ABI, shorter stent length, and the presence of diabetes; at 2 years, preprocedure ABI and the presence of diabetes; and at 3 years, the preprocedure ABI. CONCLUSIONS:The techniques used to reestablish antegrade flow in these superficial femoral arteries yielded a high success rate. In addition, the use of angioplasty with stents may improve patency rates over angioplasty without stents.

Different intravascular ultrasound (IVUS) systems vary in their image presentation. The purpose of this study was to compare four IVUS systems in vitro to determine the accuracy of tissue characterization of atherosclerotic plaque compared with histology. Ninety-eight plaque segments from 23 formalin-fixed human iliac arteries were imaged in saline at room temperature with four different IVUS systems. To assess the accuracy of IVUS in describing plaque, three types of analysis were performed: (1) the ability to identify the presence and extent of lumen or plaque boundary; (2) sensitivity, specificity, and interobserver variability of IVUS in qualitatively identifying plaque components compared with histology; and (3) quantification of calcification. The synthetic aperture device had a lower sensitivity in identifying lumen and plaque boundaries (87%, 38% respectively) compared with other machines (96%-100%, 95%-100%). All three mechanically rotating systems had fair to good sensitivities for identifying calcification (57%-73%) or lipid filled areas (50%-83%). The sensitivity of discriminating fibrous tissue from fatty areas was low (39%-52%). The synthetic aperture system had a significantly lower sensitivity for identifying all three tissue types (4%-21%). There was significant interobserver variability (kappa value = 0.47-0.68) as well as machine to machine variability (kappa value = 0.52) for tissue characterization. Calcified areas were underestimated by System 1 (p < .05) and System 4 (p < .01) because of weaker echo reflections or poor image quality. There are significant differences in image representation among these four IVUS systems in the diagnosis of tissue components of complex atherosclerotic plaque. These variabilities should be considered when interpreting studies performed with different machines.