Akinori Sumiyoshi

Ex vivo assessment of neointimal characteristics after drug-eluting stent implantation: Optical coherence tomography and histopathology validation study.

BACKGROUND Optical coherence tomography (OCT) is one of the tools trying to distinguish neoatherosclerosis from other neointimal tissue but its role has to be still validated. This study evaluated the diagnostic accuracy of OCT for characterization of lipid-atherosclerotic neointima following drug-eluting stent (DES) implantation. METHODS Twelve stented coronary arteries from the 7 autopsy hearts were imaged by OCT. These OCT images were compared with histology. By OCT, the morphological appearances of neointima were classified into three patterns: homogeneous pattern, heterogeneous pattern with visible strut, or heterogeneous pattern with invisible strut. RESULTS Of 21 histological cross-sections, 6 were categorized as homogeneous patterns (29%), 11 as heterogeneous patterns with visible stent strut (52%), and 4 as heterogeneous patterns with invisible stent strut (19%). All homogeneous patterns were composed of smooth muscle cells with collagen fibers. The heterogeneous patterns with visible stent strut included proteoglycan-rich myxomatous matrix and calcium deposition. On the other hand, the heterogeneous patterns with invisible stent strut comprised atheromatous tissue, including a large amount of foam cell accumulation (25%) or large fibroatheroma/necrotic core (75%) inside the stent struts within neointima. The optical attenuation coefficient was highest in the heterogeneous pattern with invisible stent strut due to scattering of light by atheromatous tissue. CONCLUSION The heterogeneous patterns with invisible stent strut on OCT imaging identify the presence of lipid-atherosclerotic tissue within neointima after DES. This may suggest the potential capability of OCT based on visualization of stent struts for discriminating atheromatous formation within neointima from other neointimal tissue.

Intravascular Ultrasound-Derived Stent Dimensions as Predictors of Angiographic Restenosis Following Nitinol Stent Implantation in the Superficial Femoral Artery.

Purpose: To identify intravascular ultrasound (IVUS) measurements that can predict angiographic in-stent restenosis (ISR) following nitinol stent implantation in superficial femoral artery (SFA) lesions. Methods: A retrospective review was conducted of 97 patients (mean age 72.9±8.9 years; 63 men) who underwent IVUS examination during endovascular treatment of 112 de novo SFA lesions between July 2012 and December 2014. Self-expanding bare stents were implanted in 46 lesions and paclitaxel-eluting stents in 39 lesions. Six months after stenting, follow-up angiography was conducted to assess stent patency. The primary endpoint was angiographic ISR determined by quantitative vascular angiography analysis at the 6-month follow-up. Variables associated with restenosis were sought in multivariate analysis; the results are presented as the odds ratio (OR) and 95% confidence interval (CI). Results: At follow-up, 27 (31.8%) angiographic ISR lesions were recorded. The lesions treated with uncoated stents were more prevalent in the ISR group compared with the no restenosis group (74.1% vs 44.8%, p=0.02). Lesion length was longer (154.4±79.5 vs 109.0±89.3 mm, p=0.03) and postprocedure minimum stent area (MSA) measured by IVUS was smaller (13.9±2.8 vs 16.3±1.6 mm2, p<0.001) in the ISR group. Multivariate analysis revealed that bare stent use (OR 7.11, 95% CI 1.70 to 29.80, p<0.01) and longer lesion length (OR 1.08, 95% CI 1.01 to 1.16, p=0.04) were predictors of ISR, while increasing postprocedure MSA (OR 0.58, 95% CI 0.41 to 0.82, p<0.01) was associated with lower risk of ISR. Receiver operating characteristic analysis identified a MSA of 15.5 mm2 as the optimal cutpoint below which the incidence of restenosis increased (area under the curve 0.769). Conclusion: Postprocedure MSA can predict ISR in SFA lesions, which suggests that adequate stent enlargement during angioplasty might be required for superior patency.

Histopathological validation of optical frequency domain imaging to quantify various types of coronary calcifications.

Aims This study evaluated whether optical frequency domain imaging (OFDI) could identify various coronary calcifications and accurately measure calcification thickness in comparison with histopathology. Methods and results A total of 902 pathological cross‐sections from 44 coronary artery specimens of human cadavers were examined to compare OFDI and histological images. Histological coronary calcification was classified into four different types: (i) superficial dense calcified plates, (ii) deep intimal calcification, (iii) scattered microcalcification, and (iv) calcified nodule. The thickness of calcification was measured when both the leading and trailing edges of calcification were visible on OFDI. Of the 902 histological cross‐sections, 158 (18%) had calcification: 105 (66%) were classified as superficial dense calcified plates, 20 (13%) as deep intimal calcifications, 30 (19%) as scattered microcalcifications, and 3 (2%) as calcified nodules. Superficial dense calcified plates appeared as well‐delineated heterogeneous signal‐poor regions with sharp borders on OFDI. Deep intimal calcifications could not be identified on OFDI. Scattered microcalcification appeared as homogeneous low intensity areas with indiscriminant borders. Calcified nodule, a high‐backscattering protruding mass with an irregular surface, also appeared as a low intensity area with a diffuse border. The ROC analysis identified calcium thicknesses <893 µm as cut points for the prediction of measurable calcification (72% sensitivity and 91% specificity, area under the curve = 0.893, P < 0.001). Conclusion Our study demonstrated the potential capability of OFDI to characterize various types of coronary calcifications, which may contribute to the understanding of the pathogenesis of coronary atherosclerosis.

Navifocus WR is the promising intravascular ultrasound for navigating the guidewire into true lumen during the coronary intervention for chronic total occlusion

We describe an initial clinical chronic total occlusion (CTO) case in which CTO-specific intravascular ultrasound (IVUS): Navifocus WR was useful for navigating the second guidewire into the true lumen under the IVUS observation from the subintimal space.

Strut Coverage After Paclitaxel-Eluting Stent Implantation in the Superficial Femoral Artery

In the superficial femoral artery (SFA), quantitative analysis for vascular healing response after self-expanding nitinol bare metal stent (BMS) or drug-eluting stent (DES) implantation is limited. The purpose of this study was to evaluate the endothelial strut coverage after nitinol paclitaxel-

Impact of analysis interval size on the quality of optical frequency domain imaging assessments of stent implantation for lesions of the superficial femoral artery.

This study aimed to investigate the influence of analysis interval size on optical frequency domain imaging (OFDI) assessment of stent therapy for lesions of the superficial femoral artery (SFA). Background. No consensus or validating data are available with respect to the methodology of intravascular imaging analysis for the peripheral arteries. Methods. OFDI was performed for 30 SFA lesions, during endovascular therapy and at the 6‐month follow‐up. Initially, lumen and stent borders were traced at 1‐mm axial intervals. Volumes were calculated using a PC‐based software, and the volume index (VI) was defined as the volume divided by the stent length. Two additional OFDI analyses were performed using 2‐mm and 5‐mm intervals, thereby reducing the number of cross‐sectional image frames analyzed. Results. The mean stent length was 89.7 ± 35.2 mm. The mean difference in baseline minimum lumen area (MLA) was 0.4 mm2 between MLA values from the 1‐mm and 2‐mm interval analyses, and 2.2 mm2 between MLA values from the 1‐mm and 5‐mm interval analyses. In volumetric analysis, there were excellent correlations and good agreements for stent, lumen, and neointimal VI measurements obtained on the basis of different analysis intervals. Conclusions. Using large intervals in OFDI analyses of SFA lesions resulted in few differences in measurement variability of volumetric parameters. However, planar analysis for MLA assessment can be susceptible to high variability when large intervals are applied.

Impact of stent diameter on vascular response after self-expanding paclitaxel-eluting stent implantation in the superficial femoral artery ☆

BACKGROUND The optimal sizing of self-expanding paclitaxel-eluting stents (PES) in the treatment for superficial femoral artery (SFA) lesions is unclear. This study sought to investigate the influence of PES diameter on stent patency in SFA lesions using optical frequency domain imaging (OFDI). METHODS A total of 20 de novo SFA lesions were randomized 1:1 to receive either self-expanding PES with a nominal diameter of 6mm or 8mm. Follow-up angiography and OFDI was scheduled six months after stent implantation, and volumetric OFDI analysis was performed to evaluate vascular response to the stents. Volume index (VI) was defined as the volume divided by the stent length. The primary end point was lumen VI at the 6-month follow-up. Secondary end point was minimum lumen diameter (MLD) by quantitative vascular angiography (QVA) at the follow-up. RESULTS Stent length was 78.0±23.9mm in the 6-mm group and 70.0±23.6mm in the 8-mm group (p=0.46). Baseline QVA data were also similar between the two groups. MLD immediately after stent implantation was similar between the two groups (4.2±0.5mm in the 6-mm group and 3.9±0.5mm in the 8-mm group, p=NS). At the 6-month follow-up, MLD was greater in the 8-mm group compared to the 6-mm group (4.0±1.0mm vs. 3.2±0.4mm, p<0.05). Stent VI was larger in the 8-mm group (28.4±6.7mm3/mm vs. 22.2±1.2mm3/mm, p=0.01). Neointimal VI was similar between the two groups (5.8±2.9mm3/mm vs. 5.2±2.6mm3/mm, p=0.68). Lumen VI was greater in the 8-mm group (23.2±7.6mm3/mm vs. 17.3±2.6mm3/mm, p=0.04). CONCLUSIONS Chronic stent enlargement resulted in greater lumen area after implantation of self-expanding PES with a large diameter at the mid-term follow-up. Stent diameter might be important for stent patency in procedure with PES for SFA lesions.

Right Sinus of Valsalva Aneurysm Causing Acute Myocardial Infarction

Received July 1, 2015; revised manuscript received August 26, 2015; accepted August 27, 2015; released online September 28, 2015 Time for primary review: 9 days Division of Cardiovascular Medicine and Coronary Heart Disease, Department of Internal Medicine (A.S., K.F., M.S., T.I., K.M., H.T., T.H., T.S., M.N., T.M., M.I.), Department of Surgical Pathology (H.H.), Department of Cardiovascular Surgery (M.R., Y.M.), Hyogo College of Medicine, Nishinomiya, Japan Mailing address: Masaharu Ishihara, MD, PhD, Professor, Division of Coronary Heart Disease, Department of Internal Medicine, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya 663-8501, Japan. E-mail: ishifami@fb3.so-net.ne.jp ISSN-1346-9843 doi: 10.1253/circj.CJ-15-0709 All rights are reserved to the Japanese Circulation Society. For permissions, please e-mail: cj@j-circ.or.jp Right Sinus of Valsalva Aneurysm Causing Acute Myocardial Infarction

Impact of low tissue backscattering by optical coherence tomography on endothelial function after drug-eluting stent implantation

This study evaluated the impact of optical coherence tomography (OCT)-derived low-backscattered tissue on mid-term coronary endothelial function after drug-eluting stent (DES) implantation. Although OCT enables detailed in vivo evaluation of neointimal tissue characterization after DES implantation, its association with physiological vascular healing response is unclear. Thirty-three stable angina pectoris patients underwent OCT examination and endothelial function testing with intracoronary infusion of incremental doses of acetylcholine 8-month after DES implantation in a single lesion of the left anterior descending artery. Neointimal tissue was classified into two patterns based on the predominant OCT light backscatter: high backscatter and low backscatter. Although the presence of uncovered or malapposed stent strut was not associated with the degree of vasoconstriction, the degree of vasoconstriction was significantly greater in the DES with low-backscattered neointima than in the DES without low-backscattered neointima (− 32.1 ± 25.7 vs. − 4.1 ± 20.1%, p = 0.003). Moreover, there was an inverse linear relationship between low backscatter tissue index and degree of vasoconstriction after acetylcholine infusion (r = 0.50 and p = 0.003). The endothelium-dependent vasomotor response after 8-month of DES was impaired in patients with low neointimal tissue backscatter on OCT imaging. OCT assessment of low-backscattered tissue may be used as surrogate markers for impairment of endothelial function after DES.

Iatrogenic Injury of Right Coronary Artery During Tricuspid Annuloplasty

coronary artery (Figure 1A,B). Under a standard cardiopulmonary bypass approach with intermittent cold blood cardioplegia, left sided maze procedure and mitral valve replacement with a 25-mm Magna Mitral Ease Heart Valve (Edwards Lifesciences, Irvine, CA, USA) were performed. Snares were placed A 71-year-old woman with refractory heart failure resulting from rheumatic mitral valve disease, severe tricuspid regurgitation, and atrial fibrillation was referred for surgery. Preoperative coronary arteriography showed a stenotic lesion in the proximal segment of the left ascending coronary artery and an intact right