Search

Background: Struts have been considered as covered when tissue overlying the struts is >0 μm by optical coherence tomography (OCT). However, there is no confirmatory study to validate this definition by histology which is the gold standard. The aim of the present study was to assess the appropriate cutoff value of neointimal thickness of stent strut coverage by OCT with histology confirmation., Methods: We performed ex vivo OCT imaging of human coronary arteries with stents at autopsy. A total of 46 stents in 39 vessels from 25 patients were examined in this study, and a total of 165 cross-sectional images were co-registered with histology to determine the optimal cutoff value for strut coverage by OCT which was defined as luminal endothelial cells with 2 abluminal layers of smooth muscles cells and matrix. Considering the resolution of OCT is 10 to 20 μm, the cutoff values were assessed at ≥20, ≥40, and ≥60 μm., Results: A total of 2235 struts were reviewed by histology, 1216 were considered as well-matched struts which were analyzed in this study. By histology, 160 struts were identified as uncovered, while 1056 struts were covered. The OCT assessment without consideration of neointimal thickness yielded a poor specificity of 37.5% and sensitivity 100%. Of 3 cutoff values, the cutoff value of ≥40 μm yielded the best sensitivity (99.3%), specificity (91.0%), positive predictive value (98.6%), and negative predictive value (95.6%) as compared with ≥20 and ≥60 μm., Conclusions: Neointimal thickness ≥40 μm by OCT yielded the most accurate cutoff value to identify stent strut coverage validated by histology.

Objectives: The aim of this study was to explore the pathology of in-stent chronic total occlusion (IS-CTO) in bare-metal (BMS) versus drug-eluting stents (DES)., Background: Despite a relatively high prevalence of IS-CTO, little is known about the underlying etiology and histopathologic characteristics of the occlusion., Methods: From CVPath Institute's stent registry of human native coronary arteries, the authors identified 56 lesions (32 BMS and 24 DES) from 54 patients with IS-CTO. Sections of stented coronary arteries were examined for histological features of IS-CTO. The underlying mechanisms of IS-CTO were determined along with the histopathological characteristics., Results: The pathological prevalence of IS-CTO was significantly higher in BMS versus DES cases at autopsy (11.7% vs. 5.9%; p = 0.01). The most frequent etiology of IS-CTO was acute thrombotic occlusion (51% in BMS vs. 67% in DES), followed by restenosis (31% vs. 8%) and neoatherosclerotic rupture (9% vs. 4%). The proximal lumen pattern was abrupt in 67% of BMS and in 57% of DES, whereas the distal lumen was tapered in 68% of BMS and in 74% of DES. BMS showed longer fibrous cap of IS-CTO than DES in both proximal (4.6 mm vs. 1.6 mm; p = 0.06) and distal (5.3 mm vs. 2.0 mm; p = 0.06)., Conclusions: At autopsy, IS-CTO was observed more frequently in BMS versus DES, with acute thrombotic occlusion being the most frequent cause, followed by restenosis (especially in BMS) and neoatherosclerotic rupture. Our findings shed new light upon the frequency, mechanisms, and pathology of IS-CTO., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to identify histological features that correlate with terms commonly used to describe optical coherence tomographic (OCT) and optical frequency-domain imaging (OFDI) images of stented vessels, by means of a histopathological validation study using stented human coronary arteries., Background: OCT imaging and OFDI are used to evaluate vascular responses to stent implantation. Descriptive terms such as "peristrut low attenuation" and "heterogeneous" have been used to describe neointimal characteristics that may have clinical relevance. However, only limited histopathological correlations are available., Methods: Using the CVPath stent registry, 19 cases were identified in whom implantation duration was >30 days and OCT imaging or OFDI and histological findings were available. Consecutive OCT or OFDI frames (n = 1,063) of stented coronary arteries were categorized according to their predominant imaging features in 1-mm intervals. Coregistration of OCT or OFDI frames and histopathological cross sections was performed in 111 frames., Results: Seven distinct OCT or OFDI patterns were found: homogenous (45%), layered (15%), high intensity with high attenuation (14%), intraluminal protruding masses (8%), peristrut low attenuation (7%), heterogeneous (2%), and honeycomb (1%). Histopathologically, the homogenous pattern correlated most often with smooth muscle cells within collagenous/proteoglycan matrix and less often with organized thrombus. The layered pattern correlated with healed neointimal rupture or erosion, peristrut neovascularization, or smooth muscle cells within collagen/proteoglycan matrix. High intensity with high attenuation correlated with superficial macrophage accumulation in the majority of cases, but with other histological findings in 30% of cases. The diagnostic accuracy was greater in restenotic lesions. The only OCT or OFDI finding that had a single histological feature was the honeycomb pattern., Conclusions: This study suggests a lack of correlation between OCT image patterns and distinct histological tissue characteristics., (Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: The study interrogated an autopsy registry to investigate the histopathologic features of early stent thrombosis (ST) in patients presenting with acute coronary syndrome (ACS)., Background: The occurrence of early ST following percutaneous coronary intervention (PCI) for ACS remains a clinical problem despite advances in stent technology in both bare-metal and drug-eluting stents., Methods: Sixty-seven stented coronary lesions from 59 patients who presented with ACS and died within 30 days were included. Stented segments were cross sectioned at 3 to 4 mm intervals and evaluated by light microscopy, and morphometric analysis was performed., Results: Early ST (<30 days of PCI) was identified in 34 (58%) of the 59 patients. Early ST was dependent on the underlying plaque morphology and underlying thrombus burden: presence of necrotic core prolapse was more frequent in thrombosed lesions compared with patent lesions (70% vs. 43%, p = 0.045) and maximal underlying thrombus thickness was significantly greater in thrombosed versus patent lesions. All 3 patients with false lumen stenting had ST. Detailed analysis revealed that the percent of necrotic core prolapse, medial tear, or incomplete apposition was significantly greater in the early ST compared with patent group (28% vs.11%, p < 0.001; 27% vs. 15% p = 0.004; and 34% vs. 18% p = 0.008, respectively). Multivariate analysis revealed that maximal depth of strut penetration, % strut with medial tear, and % struts with incomplete apposition were the primary indicators of early ST., Conclusions: The current autopsy study highlights the impact of thrombus burden and suboptimal stent implantation in unstable lesions as a trigger of early ST, suggesting that improvement in implantation technique and refinement of stent design may improve clinical outcomes of ACS patients., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

The SYNTAX score stratifies risk among drug-eluting stent-treated patients and is based on lesion characteristics alone. The Clinical SYNTAX Score (CSS) combines the SYNTAX score with age, ejection fraction, and creatinine clearance. We assessed its ability to stratify long-term outcomes in sirolimus-eluting stents (SES)-treated patients. Between August 2004 and March 2005, 249 patients were treated with SES. Clinical follow-up was evaluated at more than 5 years. The CSS was available for 206 patients. More than 5-year clinical follow-up data (mean 2114 ± 107 days) and CSS (range 1-322, mean 35.3 ± 49.9, median 17.5) were available for 201 patients. We divided these scores into tertiles: CSS-LOW ≤ 9.5, 9.5 < CSS-MID ≤ 28, and CSS-HIGH > 28. CSS-HIGH was associated with a higher death rate (CSS-LOW 9.0 %, CSS-MID 11.9 %, CSS-HIGH 41.8 %; log-rank p < 0.001) and major adverse cardiovascular events (MACE) (CSS-LOW 29.8 %, CSS-MID 35.8 %, CSS-HIGH 61.2 %; log-rank p = 0.004). Independent predictors for death were hemodialysis [hazard ratio (HR) 3.82; p < 0.001], age (HR 1.67; p = 0.003), ejection fraction (HR 0.98, p = 0.012) and CSS (HR 1.73, p = 0.028), and those for MACE were hemodialysis (HR 2.53, p = 0.002) and CSS (HR 1.40, p = 0.028). Areas under the curve for the SYNTAX score and CSS for death were 0.60 and 0.78 (p < 0.001), whereas those for MACE were 0.58 and 0.68 (p < 0.001), respectively. The CSS predicts long-term outcomes among SES-treated patients better than the SYNTAX score.

Aims The aim of our study was to investigate chronic total occlusion (CTO) in human coronary arteries to clarify the difference between CTO with prior coronary artery bypass graft (CABG) and those without prior CABG. Methods and results A total of 95 CTO lesions from 82 patients (61.6 ± 14.0 years, male 87.8%) were divided into the following three groups: CTO with CABG (n = 34) (CTO+CABG), CTO without CABG—of long-duration (n = 49) (LD-CTO) and short-duration (n = 12) (SD-CTO). A histopathological comparison of the plaque characteristics of CTO, proximal and distal lumen morphology, and negative remodelling between groups was performed. A total of 1127 sections were evaluated. Differences in plaque characteristics were observed between groups as follows: necrotic core area was highest in SD-CTO (18.6%) (LD-CTO: 7.8%; CTO+CABG: 4.5%; P = 0.02); calcified area was greatest in CTO+CABG (29.2%) (LD-CTO: 16.8%; SD-CTO: 12.1%; P = 0.009); and negative remodelling was least in SD-CTO [remodelling index (RI) 0.86] [CTO+CABG (RI): 0.72 and LD-CTO (RI): 0.68; P < 0.001]. Approximately 50% of proximal lumens showed characteristics of abrupt closure, whereas the majority of distal lumen patterns were tapered (79%) (P < 0.0001). Conclusion These pathological differences in calcification, negative remodelling, and presence of necrotic core along with proximal and distal tapering, which has been associated with greater success, help explain the differences in success rates of percutaneous coronary intervention in CTO patients with and without CABG. [ABSTRACT FROM PUBLISHER]