Sinus of Valsalva Pseudoaneurysm: An Unusual Cause of Complete Heart Block

We present a case of a young man with complete atrioventricular block and aneurysm of the right sinus of Valsalva penetrating the interventricular septum and causing severe aortic regurgitation. Chest trauma and inflammatory or infectious diseases are potential causes. Bentall-de Bono surgical repair was performed. Anatomopathologic analysis demonstrated fibrosis, hyalinization, and extensive myxoid material. (Level of Difficulty: Beginner.).

Ioxaglate Versus IoDixanol for the Prevention of Contrast-Induced Nephropathy: The IDPC Trial

BACKGROUND

Despite the potential benefits of percutaneous procedures for the assessment and treatment of coronary artery disease, these interventions require the use of iodine contrast, which might lead to contrast-induced nephropathy (CIN) and increased risk of dialysis and major adverse cardiac events (MACE).

AIMS

We sought to compare two different iodine contrasts (low vs. iso-osmolar) for the prevention of CIN among high-risk patients.

METHODS

This is a single-center, randomized (1:1) trial comparing consecutive patients at high risk for CIN referred to percutaneous coronary diagnostic and/or therapeutic procedures with low (ioxaglate) vs. iso-osmolarity (iodixanol) iodine contrast. High risk was defined by the presence of at least one of the following conditions: age >70 years, diabetes mellitus, non-dialytic chronic kidney disease, chronic heart failure, cardiogenic shock, and acute coronary syndrome (ACS). The primary endpoint was the occurrence of CIN, defined as a >25% relative increase and/or >0.5 mg/dL absolute increase in creatinine (Cr) levels compared with baseline between the 2nd and 5th day after contrast media administration.

RESULTS

A total of 2,268 patients were enrolled. Mean age was 67 years. Diabetes mellitus (53%), non-dialytic chronic kidney disease (31%), and ACS (39%) were highly prevalent. The mean volume of contrast media was 89 ml ± 48.6. CIN occurred in 15% of all patients, with no significant difference regarding the type of contrast used (iso = 15.2% vs. low = 15.1%, P>.99). Differences were not observed in specific subgroups such as diabetics, elderly, and ACS patients. At 30-day follow-up, 13 patients in the iso-osmolarity group and 11 in low-osmolarity group required dialysis (P =.8). There were 37 (3.3%) deaths in the iso-osmolarity cohort vs. 29 (2.6%) in the low-osmolarity group (P =.4).

CONCLUSION

Among patients at high risk for CIN, the incidence of this complication was 15%, and independent of the use of low- or iso-osmolar contrast.

Serial Assessment of Coronary Artery Healing of a Biodegradable Polymer Drug-Eluting Stent at 1, 2, and 3 Months by Optical Coherence Tomography (OCT)-The REPAIR Trial

BACKGROUND

Although first-generation drug-eluting stent (DES) devices have effectively achieved their main goal of reducing restenosis, their safety has been limited by suboptimal polymer biocompatibility, delayed stent endothelialization, and local drug toxicity, which ultimately prompted the development of new-generation DES options carrying biocompatible or even biodegradable polymers.

AIMS

We sought to assess the vessel-healing pattern of the novel sirolimus-eluting Inspiron DES (Scitech Medical) using serial optical coherence tomography (OCT) and assuming the hypothesis that this thin-strut (75-μm), biodegradable-polymer DES promotes a faster healing, with very early strut coverage.

METHODS

This is a prospective, multicenter, open-label, single-arm study enrolling 68 patients who underwent percutaneous coronary intervention guided by OCT. These patients were consecutively assigned into 3 groups. The first group had its OCT imaging follow-up performed at 3 months, the second group at 2 months, and the third group at 1 month.

RESULTS

Mean age was 59.5 years, 70.6% were male, 41.2% had type 2 diabetes, and 29.4% presented with acute coronary syndrome. A total of 72 lesions were treated and 1.06 stents were implanted per patient. OCT assessment of the stents at 1, 2, and 3 months showed a strut coverage of 90.41%, 93.96%, and 97.21%, respectively (P=.04).

CONCLUSION

The Inspiron DES showed an early strut healing pattern, with >90% of the struts covered by neointima within the first month and with almost all struts covered by the third month.

Healing and early stent coverage after ultrathin strut biodegradable polymer-coated sirolimus-eluting stent implantation: SiBi optical coherence tomography study

AIMS

The aim of SiBi study was to evaluate the early vascular healing and neointimal coverage after implantation of ultrathin (60 μm) biodegradable polymer-coated Tetriflex (Sahajanand Medical Technologies Pvt. Ltd., Surat, India) sirolimus-eluting stent (SES) using optical coherence tomography (OCT) at 4 to 6 weeks after implantation.

METHODS

SiBi was a single-center, observational, investigator-initiated study. From January 15, 2018 to April 15, 2018, total 29 consecutive patients who had consented and underwent OCT examination at 4-6 weeks after Tetriflex SES implantation were enrolled. All OCT images were analyzed at an independent core laboratory by analysts who were blinded to patient and procedural information.

RESULTS

Of 29 patients, four patients were excluded, as those OCT images were technically inadequate for analysis. Therefore, 25 patients were included in final OCT analysis. Average OCT analysis was performed after 35.3 ± 5 days of Tetriflex implantation. Total 14,024 stent struts in 1,520 cross sections were analyzed. Strut tissue coverage was observed in 91.26 ± 5.53% of struts and malapposed struts were seen in 0.89 ± 1.67%. The mean neointimal hyperplasia (NIH) thickness on the covered struts was 50 ± 30 μm.

CONCLUSION

A large percentage of struts were found to be covered with thin layer of NIH evenly distributed along the stent length at around 1 month from stent implantation. The results of this pilot study serve as ethical and scientific backbone to conduct an adequately powered clinical trial to evaluate outcomes of short dual-antiplatelet therapy in context of ultrathin strut stent.

Optical Coherence Tomography Versus Intravascular Ultrasound and Angiography to Guide Percutaneous Coronary Interventions: The iSIGHT Randomized Trial

[Figure: see text].

Twelve-month clinical and imaging outcomes of the uncaging coronary DynamX bioadaptor system

AIMS

We aimed to assess the safety and efficacy of the DynamX Novolimus-Eluting Coronary Bioadaptor System, a novel device that initially acts as a second-generation drug-eluting stent, but after six months frees the vessel through uncaging elements.

METHODS AND RESULTS

This multicentre study enrolled 50 patients with single de novo lesions. In-device acute lumen gain was 1.61±0.34 mm, and device and procedure success was 100%. Up to 12 months, two target lesion failures occurred: both were cardiac deaths (day 255 and day 267 post procedure). No definite or probable device thrombosis was observed. Mean late lumen loss was 0.12±0.18 mm in-device and 0.11±0.16 mm in-segment. Per intravascular ultrasound, the mean device area and mean vessel area increased significantly by 5% and 3%, respectively, while the mean lumen area was maintained. Stationary optical coherence tomography in seven patients demonstrated restoration of cyclic pulsatility, with an approximate lumen area variance of 11% between systole and diastole.

CONCLUSIONS

The DynamX bioadaptor showed drug-eluting stent-like acute performance and safety and efficacy up to one year. Positive remodelling with an increase of vessel and device area while maintaining the mean lumen area was demonstrated. Long-term follow-up and randomised trials are required to assess the benefit of this device on events beyond one year.

Comparison of neointimal coverage between ultrathin biodegradable polymer-coated sirolimus-eluting stents and durable polymer-coated everolimus-eluting stents: 6 months optical coherence tomography follow-up from the TAXCO study

Aim

The TAXCO study was designed to compare the degree of neointimal coverage and the prevalence of malapposition at 6 months subsequent to implantation of ultrathin biodegradable polymer‐coated sirolimus‐eluting stents (SES) and durable polymer‐coated everolimus‐eluting stents (EES) of thin strut thickness using optical coherence tomography (OCT).

Methods

The TAXCO study included a total of 42 patients who gave consent and underwent OCT examination between August 2017 and September 2017. Of 42, five patients' OCT examinations were of insufficient quality for quantitative analysis. Thus, the OCT analysis group consisted of 37 patients. Among them, 16 patients were treated with Xience (Abbott Vascular) and 21 with Tetriflex (Sahajanand Medical Technologies Pvt. Ltd., Surat, India), 6 (±1) months earlier at our institution. The OCT was performed using a C7 Dragonfly™ imaging catheter (St. Jude Medical Inc.). All OCT images were analyzed at an independent core laboratory (Cardiovascular Research Center, São Paulo, Brazil) by analysts who were blinded to patient and procedural information.

Results

A total of 763 crosssections (6,882 struts) were analyzed in Xience group, and 1,127 crosssections (9,968 struts) in Tetriflex group. At 6 months, on per‐lesion basis, no significant differences were observed between Xience group and Tetriflex group in mean percentage of uncovered struts (1.87 ± 3.86 vs. 2.42 ± 3.46, p = .137) and malapposed struts (0.05 ± 0.2 vs. 0.21 ± 0.69, p = .302). Strut‐level neointimal thickness also did not differ between Xience group and Tetriflex group (0.18 ± 0.12 vs. 0.14 ± 0.08 mm, p = .286).

Conclusion

This OCT study found no significant difference in strut coverage and neointimal thickness at 6 months after implantation of biodegradable polymer‐coated Tetriflex, when compared with durable polymer‐coated Xience.

Diagnostic Accuracy of 320-Row Computed Tomography for Characterizing Coronary Atherosclerotic Plaques: Comparison with Intravascular Optical Coherence Tomography

BACKGROUND/PURPOSE

This study sought to determine the diagnostic accuracy of 320-row computed tomography (320CT) for characterizing coronary atherosclerotic plaques in comparison with optical coherence tomography (OCT).

METHODS/MATERIALS

From 32 patients, 42 coronary segments were evaluated and co-registered by both 320CT and OCT. 320CT vulnerable plaque characteristics included low attenuation plaque (LAP) (<30HU), napkin-ring sign (NRS), positive remodeling (PR) and spotty calcification (SC). The presence of macrophage, neovascularization and cholesterol crystals was also determined by OCT.

RESULTS

Minimal lumen area was 2.78 ± 1.23 mm by OCT and 3.29 ± 1.49 mm by 320CT (p < 0.001). Noncalcified plaques were classified accordingly by both methods in 88.2% of the cases (p = 0.005). There was no association between any 320CT plaque type and OCT fibroatheroma (p = 0.62). The combination of 2 or more of the 320CT vulnerable plaque characteristics was associated with the presence of macrophage (74.2 vs. 25.8%; p = 0.034) and cholesterol crystals (85.7 vs. 14.3%; p = 0.04), but not with neovascularization (p = 0.65). The presence of all four characteristics demonstrated an accuracy of 75.1% for detecting OCT fibroatheroma.

CONCLUSIONS

320CT is useful for non-invasive evaluation of calcified and noncalcified tissue characteristics of coronary atheroma. The combination of all four 320CT vulnerable plaque characteristics provided the highest accuracy for detecting fibroatheromas.

SUMMARY

320CT is useful for non-invasive evaluation of calcified and noncalcified tissue characteristics of coronary atheroma. The combination of all 320CT vulnerable plaque characteristics (low attenuation plaque (<30HU), napkin-ring sign, positive remodeling and spotty calcification) provided the highest accuracy for detecting fibroatheromas compared to optical coherence tomography.

Serial Assessment of Strut Coverage of Biodegradable Polymer Drug-Eluting Stent at 1, 2, and 3 Months After Stent Implantation by Optical Frequency Domain Imaging: The DISCOVERY 1TO3 Study (Evaluation With OFDI of Strut Coverage of Terumo New Drug Eluting Stent With Biodegradable Polymer at 1, 2, and 3 Months)

BACKGROUND

To assess the vessel-healing pattern of Ultimaster drug-eluting stent using optical frequency domain imaging. Our hypothesis is that biodegradable polymer-based drug-eluting technology allows complete very early strut coverage.

METHODS AND RESULTS

The DISCOVERY 1TO3 study (Evaluation With OFDI of Strut Coverage of Terumo New Drug Eluting Stent With Biodegradable Polymer at 1, 2, and 3 Months) is a prospective, single-arm, multicenter study. A total of 60 patients with multivessel disease requiring staged procedure at 1 month were treated with Ultimaster. Optical frequency domain imaging was acquired at baseline, 1, 2, and 3 months. The primary end point is optical frequency domain imaging-assessed strut coverage at 3 months. Mean age of patients was 67.2±9.9 years, and 73.3% were male, and 36.7% presented with acute coronary syndrome. A total of 132 lesions were treated, with average 1.4 lesions per patient treated at baseline and 1.1 lesions treated at 1 month. Strut coverage at 3 months of single implanted stents (n=71, primary end point) was 95.2±5.2% and of combined single and overlapped stents was 95.4±4.9%. Strut coverage of combined single and overlapped stents at 1 (n=49) and 2 months (n=38) was 85.1±12.7% and 87.9±10.8%, respectively. The median neointimal hyperplasia thickness was 0.04, 0.05, and 0.06 mm, whereas mean neointimal hyperplasia obstruction was 4.5±2.4%, 5.2±3.4%, and 6.6±3.3% at 1, 2, and 3 months, respectively.

CONCLUSIONS

Nearly complete strut coverage was observed in this complex population very early after implantation of Ultimaster drug-eluting stent.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01844843.

CKD-EPI versus Cockcroft-Gault formula for predicting contrast-induced nephropathy following percutaneous coronary intervention in patients without significant renal impairment

INTRODUCTION

Individuals with glomerular filtration rate (GFR) ≥60 ml/min/1.73 m² estimated by the Cockcroft-Gault formula (CG) who undergo percutaneous coronary intervention (PCI) frequently develop contrast-induced nephropathy (CIN). This study aimed to assess whether individuals with significant renal impairment assessed by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula, but not by CG, more often develop CIN following PCI than those without renal impairment by either formula.

METHODS

In this cross-sectional study analyzing patients with baseline CG GFR ≥60 ml/min/1.73 m² before PCI, subjects were divided into two groups according to CIN occurrence. Baseline CKD-EPI GFR was calculated for all patients.

RESULTS

We analyzed 140 patients. Baseline GFR was 87.5±21.3 and 77.1±15.0 ml/min/1.73 m² for CG and CKD-EPI, respectively. CIN occurred in 84.6% of individuals with baseline CKD-EPI GFR <60 ml/min/1.73 m² vs. 51.1% of those without. Males and those with higher body mass index were more likely to present baseline CKD-EPI GFR <60 ml/min/1.73 m² (p=0.021). Non-ionic contrast agent use and baseline CKD-EPI GFR ≥60 ml/min/1.73 m² were protective factors against CIN. Greater amounts of contrast agent and acute coronary syndrome were associated with higher CIN risk. In subjects with serum creatinine <1.0 mg/dl, GFR was more likely to be overestimated by CG, but not by CKD-EPI (sensitivity 100.0%; specificity 52.0%).

CONCLUSION

In patients undergoing PCI without renal dysfunction by CG, a finding of CKD-EPI GFR <60 ml/ min/1.73 m² was associated with a higher probability of CIN, especially among men and those with higher body mass index.

Impact of the Occlusion Duration on the Performance of J-CTO Score in Predicting Failure of Percutaneous Coronary Intervention for Chronic Total Occlusion

OBJECTIVES

The present study examined the association between Multicenter CTO Registry in Japan (J-CTO) score in predicting failure of percutaneous coronary intervention (PCI) correlating with the estimated duration of chronic total occlusion (CTO).

BACKGROUND

The J-CTO score does not incorporate estimated duration of the occlusion.

METHODS

This was an observational retrospective study that involved all consecutive procedures performed at a single tertiary-care cardiology center between January 2009 and December 2014.

RESULTS

A total of 174 patients, median age 59.5 years (interquartile range [IQR], 53-65 years), undergoing CTO-PCI were included. The median estimated occlusion duration was 7.5 months (IQR, 4.0-12.0 months). The lesions were classified as easy (score = 0), intermediate (score = 1), difficult (score = 2), and very difficult (score ≥3) in 51.1%, 33.9%, 9.2%, and 5.7% of the patients, respectively. Failure rate significantly increased with higher J-CTO score (7.9%, 20.3%, 50.0%, and 70.0% in groups with J-CTO scores of 0, 1, 2, and ≥3, respectively; P<.001). There was no significant difference in success rate according to estimated duration of occlusion (P=.63). Indeed, J-CTO score predicted failure of CTO-PCI independently of the estimated occlusion duration (P=.24). Areas under receiver-operating characteristic curves were computed and it was observed that for each occlusion time period, the discriminatory capacity of the J-CTO score in predicting CTO-PCI failure was good, with a C-statistic >0.70.

CONCLUSION

The estimated duration of occlusion had no influence on the J-CTO score performance in predicting failure of PCI in CTO lesions. The probability of failure was mainly determined by grade of lesion complexity.

Randomized Comparison of Absorb Bioresorbable Vascular Scaffold and Mirage Microfiber Sirolimus-Eluting Scaffold Using Multimodality Imaging

OBJECTIVES

The primary objective of this study was to evaluate the safety and effectiveness of the Mirage (Manli Cardiology, Singapore) bioresorbable microfiber sirolimus-eluting scaffold compared with the Absorb (Abbott Vascular, Santa Clara, California) bioresorbable vascular scaffold in the treatment of stenotic target lesions located in native coronary arteries, ranging from ≥2.25 to ≤4.0 mm in diameter. Secondary objectives were to establish the medium-term safety, effectiveness, and performance of the Mirage device.

BACKGROUND

The current generation of bioresorbable scaffolds has several limitations, such as thick square struts with large footprints that preclude their deep embedment into the vessel wall, resulting in protrusion into the lumen with microdisturbance of flow. The Mirage sirolimus-eluting bioresorbable microfiber scaffold is designed to address these concerns.

METHODS

In this prospective, single-blind trial, 60 patients were randomly allocated in a 1:1 ratio to treatment with a Mirage sirolimus-eluting bioresorbable microfiber scaffold or an Absorb bioresorbable vascular scaffold. The clinical endpoints were assessed at 30 days and at 6 and 12 months. In-device angiographic late loss at 12 months was quantified. Secondary optical coherence tomographic endpoints were assessed post-scaffold implantation at 6 and 12 months.

RESULTS

Median angiographic post-procedural in-scaffold minimal luminal diameters of the Mirage and Absorb devices were 2.38 mm (interquartile range [IQR]: 2.06 to 2.62 mm) and 2.55 mm (IQR: 2.26 to 2.71 mm), respectively; the effect size (d) was -0.29. At 12 months, median angiographic in-scaffold minimal luminal diameters of the Mirage and Absorb devices were not statistically different (1.90 mm [IQR: 1.57 to 2.31 mm] vs. 2.29 mm [IQR: 1.74 to 2.51 mm], d = -0.36). At 12-month follow-up, median in-scaffold late luminal loss with the Mirage and Absorb devices was 0.37 mm (IQR: 0.08 to 0.72 mm) and 0.23 mm (IQR: 0.15 to 0.37 mm), respectively (d = 0.20). On optical coherence tomography, post-procedural diameter stenosis with the Mirage was 11.2 ± 7.1%, which increased to 27.4 ± 12.4% at 6 months and remained stable (31.8 ± 12.9%) at 1 year, whereas the post-procedural optical coherence tomographic diameter stenosis with the Absorb was 8.4 ± 6.6%, which increased to 16.6 ± 8.9% and remained stable (21.2 ± 9.9%) at 1-year follow-up (Mirage vs. Absorb: d_{post-procedure} = 0.41, d_{6 months} = 1.00, d_{12 months} = 0.92). Angiographic median in-scaffold diameter stenosis was significantly different between study groups at 12 months (28.6% [IQR: 21.0% to 40.7%] for the Mirage, 18.2% [IQR: 13.1% to 31.6%] for the Absorb, d = 0.39). Device- and patient-oriented composite endpoints were comparable between the 2 study groups.

CONCLUSIONS

At 12 months, angiographic in-scaffold late loss was not statistically different between the Mirage and Absorb devices, although diameter stenosis on angiography and on optical coherence tomography was significantly higher with the Mirage than with the Absorb. The technique of implantation was suboptimal for both devices, and future trials should incorporate optical coherence tomographic guidance to allow optimal implantation and appropriate assessment of the new technology, considering the novel mechanical properties of the Mirage.

Role of invasive imaging in acute and long-term assessment of bioresorbable scaffold technology

Fully bioresorbable scaffolds (BRS) represent a novel approach for the percutaneous treatment of coronary artery stenosis, providing temporary vessel scaffolding with drug-eluting capability during the restenosis-prone phase of the vascular healing. Beyond this initial critical period, when mechanical scaffolding support is no longer necessary, the device is bioresorbed, restoring the normal vascular physiology with the aim to eliminate the long-term safety concerns related to permanent metallic implants. Nonetheless, current BRS technology suffers from limited mechanical properties as compared to available metallic platforms, requiring careful attention to lesion preparation, accurate vessel sizing, and implantation technique. Intravascular imaging has played an important role in providing knowledge on the acute effects after BRS deployment, and it helped refine the current technique of BRS implantation. In addition, extensive work with multiple intravascular imaging modalities have also contributed to the understanding of the unique dynamic vascular changes that are experienced in the treated segment from post-implantation up to complete device bioresorption. In this manuscript, we review the role of invasive imaging modalities-from angiography to sound- and light-based techniques-to guide BRS implantation procedures, to assess its acute results postimplantation, and the changes experienced in the long-term until complete bioresorption has ensued. © 2016 Wiley Periodicals, Inc.

Volumetric characterization of human coronary calcification by frequency-domain optical coherence tomography

BACKGROUND

Coronary artery calcification (CAC) presents unique challenges for percutaneous coronary intervention. Calcium appears as a signal-poor region with well-defined borders by frequency-domain optical coherence tomography (FD-OCT). The objective of this study was to demonstrate the accuracy of intravascular FD-OCT to determine the distribution of CAC.

METHODS AND RESULTS

Cadaveric coronary arteries were imaged using FD-OCT at 100-μm frame interval. Arteries were subsequently frozen, sectioned and imaged at 20-μm intervals using the Case Cryo-Imaging automated system(TM). Full volumetric co-registration between FD-OCT and cryo-imaging was performed. Calcium area, calcium-lumen distance (depth) and calcium angle were traced on every cross-section; volumetric quantification was performed offline. In total, 30 left anterior descending arteries were imaged: 13 vessels had a total of 55 plaques with calcification by cryo-imaging; FD-OCT identified 47 (85%) of these plaques. A total of 1,285 cryo-images were analyzed and compared with corresponding co-registered 257 FD-OCT images. Calcium distribution, represented by the mean depth and the mean calcium angle, was similar, with excellent correlation between FD-OCT and cryo-imaging respectively (mean depth: 0.25±0.09 vs. 0.26±0.12mm, P=0.742; R=0.90), (mean angle: 35.33±21.86° vs. 39.68±26.61°, P=0.207; R=0.90). Calcium volume was underestimated in large calcifications (3.11±2.14 vs. 4.58±3.39mm(3), P=0.001) in OCT vs. cryo respectively.

CONCLUSIONS

Intravascular FD-OCT can accurately characterize CAC distribution. OCT can quantify absolute calcium volume, but may underestimate calcium burden in large plaques with poorly defined abluminal borders.

Serial greyscale and radiofrequency intravascular ultrasound assessment of plaque modification and vessel geometry at proximal and distal edges of bare metal and first-generation drug-eluting stents

BACKGROUND

Little is known about the correlation between modifications in plaque composition at stent edges and the changes in vessel geometry. This study sought to evaluate, by serial greyscale intravascular ultrasound (IVUS) and Virtual Histology intravascular ultrasound (VH-IVUS), the modifications in plaque composition at the edges of drug-eluting and bare metal stents and the correlation of these findings with changes in the measurements of vessel, lumen and plaque area at those segments.

METHODS AND RESULTS

Single-centre, prospective and randomised (1:1) evaluation of 40 patients with acute coronary syndrome treated with bare metal (Driver; Medtronic, Santa Clara, CA, USA; n=20 patients) or drug-eluting stents (Cypher; Cordis, Miami Lakes, FL, USA; n=20 patients). IVUS and VH-IVUS assessments were done post-procedure and at nine months. Primary endpoint included the modification in vessel, lumen and plaque area and in the composition of the plaque in the mean time between the baseline and follow-up procedure. At the proximal edge of the vessel treated with the Cypher stent, a trend toward positive vessel remodelling (D=+0.6 mm², p=0.06) was observed while at the distal edge, less plaque growth (D=+0.2 mm² vs. D=+1.1 mm², p<0.001), resulted in a larger lumen area at follow-up. By VH, there was a marked reduction in the percentage of fibrotic tissue and necrotic core at the edges of both stents and a positive correlation was seen between increase in percentage of fibro-fatty component and increase in plaque area (r=0.78, p=0.01).

CONCLUSION

Patients treated with drug-eluting stents (DES) experienced less plaque growth, especially at the distal edge of the stents. Modifications in plaque composition, with increase in fibrofatty tissue component, may partially explain these findings.

Serial Evaluation of Vascular Response After Implantation of a New Sirolimus-Eluting Stent With Bioabsorbable Polymer (MISTENT): an optical coherence tomography and histopathological study

BACKGROUND

Novel vascular scaffolds aim at equipoise between safety and efficacy. Intravascular optical coherence tomography (OCT) allows in-vivo serial assessment of stent-vessel interactions with high resolution and frequent sampling and may complement histology assessment. We investigated the vascular response to a novel absorbable coating sirolimus-eluting stent (AC-SES) by means of serial OCT and histology evaluation in a porcine model.

METHODS

One AC-SES and one bare-metal stent (BMS) were implanted in separate coronary arteries of three Yucatan mini-swine. Serial OCT was performed post procedure and at 3-, 28-, 90-, and 180-day follow-up. Normalized optical density (NOD) was used for the assessment of tissue response over time. Histological evaluation was performed at day 180.

RESULTS

A total of 6408 stent struts were analyzed. OCT revealed 100% of struts covered at 28 days, and a significant difference in NOD from 3 to 28 days (0.64 ± 0.07 vs 0.71 ± 0.05, respectively; P<.001) in the AC-SES group. Neointimal thickness was 0.14 ± 0.08 mm, 0.17 ± 0.11 mm, and 0.16 ± 0.09 mm in the AC-SES group and 0.18 ± 0.10 mm, 0.14 ± 0.09 mm, and 0.10 ± 0.08 mm in the BMS group, while rates of uncovered struts were 0%, 0%, and 3.1% and 1.4%, 7.8%, and 21.5%, respectively, at 28, 90, and 180 days. Minimal inflammation and a mature endothelialization were demonstrated in both groups by histology.

CONCLUSION

OCT serial assessment of vascular response suggested NIH maturation 28 days following AC-SES implantation in pigs. These findings, coupled with histological demonstration of low inflammation scores and complete endothelial coverage as measured at 180 days, suggest a satisfactory healing response to AC-SES.

Assessing the temporal course of neointimal hyperplasia formation after different generations of drug-eluting stents

OBJECTIVES

This study sought to assess the temporal course of neointimal hyperplasia (NIH) formation following implantation of 2 different generations of drug-eluting stents (DES).

BACKGROUND

The amount of NIH following DES implantation correlates with the potency of the antiproliferative drug, its kinetic release, as well as some individual characteristics, as the presence of diabetes mellitus (DM). Recently, some publications have suggested a continuous growth of NIH following DES, which in some cases, might result in late "catch-up."

METHODS

Twenty-five patients with single, de novo lesions were treated with sirolimus-eluting stents (SES) (n = 12) and biolimus-eluting stents (BES) (n = 13) and underwent intravascular ultrasound evaluation immediately after the procedure and at 9-month and 5-year follow-ups. The primary endpoint was the comparison of the percentage of NIH obstruction between mid- and long-term follow-up.

RESULTS

Mean age was 59 years and 28% of patients had DM. Overall, the percentage of NIH obstruction significantly increased from 9 months to 5 years (1.3% at first follow-up vs. 4.8% at second follow-up, p = 0.002). There was no significant difference in the variation of vessel volume (Δ = -0.70 mm(3)/mm BES vs. Δ = 0.18 mm(3)/mm SES, p = 0.56), lumen volume (Δ = 0.40 mm(3)/mm BES vs. Δ = -0.05 mm(3)/mm SES, p = 0.71), and percentage of NIH obstruction (Δ = 3.0% BES vs. Δ = 3.8% SES, p = 0.55) among DES. However, diabetic patients had a marked NIH increase along the years (NIH volume at second follow-up: 10.15 mm(3) DM vs. 5.11 mm(3) non-DM, p = 0.028).

CONCLUSIONS

The present serial intravascular ultrasound assessment supports the occurrence of continuous NIH growth following different generations of DES. These findings seem to be particularly more pronounced among patients with DM.

Optical Coherence Tomography and Fibrous Cap Characterization

The pathophysiology of acute coronary syndromes has long been associated with atherosclerotic plaque rupture. Inflammation, thinning, and disruption of the fibrous cap have been implicated with the final processes leading to plaque rupture, but confirmation of these mechanisms of coronary thrombosis in humans has been hampered by the lack of imaging methods with sufficient resolution to resolve fibrous cap characterization and thickness in vivo. Intravascular optical coherence tomography (OCT) provides images with micron-level axial and lateral resolution, enabling detailed visualization of micro-structural changes of the arterial wall. The present article provides an overview of the potential role of OCT in identifying and characterizing fibrous cap morphology, thickness, and inflammation in human coronary plaques.

Utilization of frequency domain optical coherence tomography and fractional flow reserve to assess intermediate coronary artery stenoses: conciliating anatomic and physiologic information

Fractional flow reserve (FFR) and intravascular imaging respectively provide hemodynamic and anatomical assessments of angiographic intermediate stenoses. Frequency domain optical coherence tomography (FD-OCT) is a promising high-resolution imaging modality, but its clinical use in determining severity of coronary disease has yet to be determined. There, we set out to determine the role of FD-OCT to complement FFR in the evaluation of intermediate coronary artery stenoses. FD-OCT was planned in 176 consecutive interventional procedures at our institution to delineate the proper use of FD-OCT in clinical practice. The decision to use other invasive assessments was at the discretion of the operator. This report describes an early series of the 14 patients who underwent FFR of 18 target stenoses in addition to FD-OCT. FD-OCT was successfully performed without complications in all cases. Fractional flow reserve was <0.80 in four patients, with minimal lumen areas and reference vessel diameters ranging from 1.03 to 3.47 mm(2) and 2.60 to 2.94 mm by FD-OCT, respectively. FD-OCT was important to rule out plaque rupture, erosion and thrombosis and to help guide decision to defer PCI in six patients with acute coronary syndrome and FFR > 0.80. FD-OCT was also valuable to guide PCI strategy in tandem lesions with an FFR < 0.80. This initial experience with FD-OCT suggests a potential complementary role of physiological and anatomical assessment to guide decision making in complex clinical scenarios. Future investigations are warranted to validate these findings and define the role of FD-OCT in assessing intermediate lesions.