Accuracy of coronary computed tomography angiography for bioresorbable scaffold luminal investigation: a comparison with optical coherence tomography

To establish the accuracy of coronary computed tomography angiography (CTA) for in-scaffold quantitative evaluation with optical coherence tomography (OCT) as a reference. The translucent backbone of the bioresorbable scaffold allow us to evaluate non-invasively the coronary lumen with coronary CTA. In the ABSORB first-in-man studies, coronary CTA was shown to be feasible for quantitative luminal assessment. Nevertheless, a comparison with an intravascular modality with higher resolution has never been performed. In the ABSORB Cohort B trial, 101 patient with non-complex lesions were treated with the fully biodegradable vascular scaffold. For this analysis, all patients who underwent coronary CTA at 18 months and OCT within ±180 days were included. Coronary CTA and OCT data were analysed at an independent core laboratory for quantitative cross-sectional luminal dimensions. The primary objective was the accuracy and precision of coronary CTA for in-scaffold minimal lumen area assessment, with OCT as a reference. Among the 101 patients of the ABSORB Cohort B trial, 35 underwent both OCT and coronary CTA. The feasibility of quantitative evaluation was 74%. In the scaffolded segment, coronary CTA underestimated minimal lumen area by 9.8% (accuracy 0.39 mm², precision 1.0 mm², 95% limits of agreement ?1.71 to 2.50 mm²). A similar level of agreement was observed in the non-scaffolded segment. Compared to OCT, coronary CTA appears to be accurate for the estimation of in-scaffold luminal areas, with no difference compared to the non-scaffolded region.     

Evaluation with in vivo optical coherence tomography and histology of the vascular effects of the everolimus-eluting bioresorbable vascular scaffold at two years following implantation in a healthy porcine coronary artery model: implications of pilot results for future pre-clinical studies

To quantify with in vivo OCT and histology, the device/vessel interaction after implantation of the bioresorbable vascular scaffold (BVS). We evaluated the area and thickness of the strut voids previously occupied by the polymeric struts, and the neointimal hyperplasia (NIH) area covering the endoluminal surface of the strut voids (NIH_EV), as well as the NIH area occupying the space between the strut voids (NIH_BV), in healthy porcine coronary arteries at 2, 3 and 4?years after implantation of the device. Twenty-two polymeric BVS were implanted in the coronary arteries of 11 healthy Yucatan minipigs that underwent OCT at 2, 3 and 4?years after implantation, immediately followed by euthanasia. The areas and thicknesses of 60 corresponding strut voids previously occupied by the polymeric struts and the size of 60 corresponding NIH_EV and 49 NIH_BV were evaluated with both OCT and histology by 2 independent observers, using a single quantitative analysis software for both techniques. At 3 and 4?years after implantation, the strut voids were no longer detectable by OCT or histology due to complete polymer resorption. However, analysis performed at 2?years still provided clear delineation of these structures, by both techniques. The median [ranges] areas of these strut voids were 0.04 [0.03?C0.16] and 0.02 [0.01?C0.07] mm² by histology and OCT, respectively. The mean (±SD) thickness by histology and OCT was 220?±?40?and 120?±?20???m, respectively. The median [ranges] NIH_EV by histology and OCT was 0.07 [0.04?C0.20] and 0.03 [0.01?C0.08] mm², while the mean (±SD) NIH_BV by histology and OCT was 0.13?±?0.07?and 0.10?±?0.06?mm². Our study indicates that in vivo OCT of the BVS provides correlated measurements of the same order of magnitude as histomorphometry, and is reproducible for the evaluation of certain vascular and device-related characteristics. However, histology systematically gives larger values for all the measured structures compared to OCT, at 2?years post implantation.     

In-stent fractional flow reserve variations and related optical coherence tomography findings: the FFR–OCT co-registration study

We sought to assess in-stent variations in fractional flow reserve (FFR) in patients with previous percutaneous coronary intervention (PCI) and to associate any drop in FFR with findings by optical coherence tomography (OCT) imaging. Suboptimal post-PCI FFR values were previously associated with poor outcomes. It is not known to which extent in-stent pressure loss contributes to reduced FFR. In this single-arm observational study, 26 patients who previously underwent PCI with drug-eluting stent or scaffold implantation were enrolled. Motorized FFR pullback during continuous intravenous adenosine infusion and OCT assessments was performed. Post-PCI FFR?<?0.94 was defined as suboptimal. At a median of 63 days after PCI (interquartile range: 59–64 days), 18 out of 26 patients (72%) had suboptimal FFR. The in-stent drop in FFR was significantly higher in patients with suboptimal FFR vs. patients with optimal FFR (0.08?±?0.07 vs. 0.01?±?0.02, p?<?0.001). Receiver operating characteristic curve analysis showed that an in-stent FFR variation of >?0.03 was associated with suboptimal FFR. In patients with suboptimal FFR, the OCT analyses revealed higher mean neointimal area (respectively: 1.06?±?0.80 vs. 0.51?±?0.23 mm²; p?=?0.018) and higher neointimal thickness of covered struts (respectively 0.11?±?0.07 vs. 0.06?±?0.01 mm; p?=?0.021). Suboptimal FFR values following stent-implantation are mainly caused by significant in-stent pressure loss during hyperemia. This finding is associated to a larger neointimal proliferation.     

Predictors of acute scaffold recoil after implantation of the everolimus-eluting bioresorbable scaffold: an optical coherence tomography assessment in native coronary arteries

This study investigated the predictors of acute recoil after implantation of everolimus-eluting BRS based on optical coherence tomography (OCT). Thirty-nine patients (56 scaffolds) were enrolled. Acute absolute recoil by quantitative coronary angiography was defined as the difference between the mean diameter of the last inflated balloon (X) and the mean lumen diameter of BRS immediately after balloon deflation (Y). Acute percent recoil was defined as (X???Y)?×?100/X. Plaque eccentricity (PE) and plaque composition (PC) were assessed by OCT. PC was classified into two different types: calcific (score?=?1), fibrous and lipid (score?=?0). Based on the mean acute scaffold recoil value of the present study, scaffolds were divided into two groups: the low acute recoil group (LAR, n?=?34) and the high acute recoil group (HAR, n?=?22). Acute percent and absolute recoil were 6.4?±?3.0?% and 0.19?±?0.11 mm. PE, PC score and scaffold/artery ratio were significantly higher in HAR than in LAR. In multivariate logistic regression analysis, PE?>?1.49, PC score (score 1) and scaffold/artery ratio >1.07 were significant positive predictors for the occurrence of acute scaffold recoil (OR 10.7, 95?% CI 2.2–51.4, p?<?0.01; OR 5.6, 95?% CI 1.9–22.0, p?=?0.04; OR 12.4, 95?% CI 2.6–65.4, p?<?0.01, respectively). Acute recoil of BRS is influenced by BRS sizing as well as OCT-derived plaque characteristics.     

Very early tissue coverage after drug-eluting stent implantation: an optical coherence tomography study

The aim of this study was to evaluate neointimal coverage in the very early phase after second-generation drug-eluting stent (DES) implantation using optical coherence tomography (OCT). Patients who underwent staged percutaneous coronary intervention within 30 days after DES implantation were enrolled. OCT was performed to observe DES previously implanted. The median time interval from implantation to OCT examination was 21.5 days. A total of 10,625 struts of 54 stents (52 everolimus-eluting stents and 2 zotarolimus-eluting stents) in 42 lesions were analyzed. Strut tissue coverage was observed in 71.1?±?19.2?% of the struts, malapposed struts in 2.56?±?3.37?%, strut tissue coverage at the side branch orifice in 10.6?±?17.2?%, and struts with protrusion in 0.95?±?3.46?%. Mean tissue thickness on the covered struts was 39.8?±?14.2 µm. The percentage of stent coverage was significantly lower in the overlapping segments than in the non-overlapping segments (48.4?±?17.5?% vs. 74.4?±?20.2?%, P?<?0.05). Most of the stent struts were covered by tissue within 30 days after second-generation DES implantation. However, the percentage of strut coverage was lower in the overlapping segments than in the non-overlapping segments, suggesting that very early interruption of dual antiplatelet therapy might result in increased risk of stent thrombosis, even in second-generation DES.     

Neointimal response to everolimus-eluting bioresorbable scaffolds implanted at bifurcating coronary segments: insights from optical coherence tomography

Heterogeneity of neointimal thickness is observed after drug-eluting stents implantation in bifurcation lesions (BL). We evaluated the vascular response of everolimus-eluting bioresorbable scaffold (BRS) struts deployed at BL using optical coherence tomography (OCT). 50 patients (64 scaffolds) underwent follow-up OCT after BRS implantation. Cross-sectional areas of each BL with a side branch more than 1.5 mm were analyzed using OCT every 200 µm. All images were divided into three regions according to shear stress: the 1/2 circumference of the vessel opposite to the ostium (OO), the vessel wall adjacent to the ostium (AO) and the side-branch ostium (SO). The %uncovered strut and the averaged neointimal thickness (NIT) were calculated. Overall, there were significant differences in both NIT and %uncovered strut among the three regions (OO, 119.2?±?68.5 μm vs. AO, 94.2?±?35.7 μm vs. SO, 80.5?±?41.4 μm, p?=?0.03; OO, 0.4?%vs. AO, 1.4?%vs. SO, 4.8?%, p?=?0.02). Scaffolds were divided into two groups: a large-ratio side-branch group (LRSB; n?=?32) and a small-ratio side-branch group (SRSB; n?=?32), based on the median value of the ratio of the diameter of side branch ostium (Ds) to that of the main branch (Dm). In the LRSB alone, there were significant differences in both NIT and %uncovered strut among the three regions (OO, 128.0?±?61.1 μm vs. AO, 97.3?±?34.3 μm vs. SO, 75.9?±?39.4 μm, p?<?0.01; OO, 0.3?% vs. AO, 2.3?% vs. SO, 8.7?%, p?<?0.01). After BRS implantation in BL, neointimal response was pronounced at the vessel wall opposite to the side branch ostium, especially in those with large side branches.     

Optical coherence tomography findings of very late stent thrombosis after drug-eluting stent implantation

Previous optical coherence tomography (OCT) studies in patients with drug-eluting stents (DESs)-related very late stent thrombosis (VLST) were scarce. Therefore, we investigated OCT findings of VLST after implantation of DESs. Using OCT, we analyzed the status of stent struts and neointimal characteristics in 18?patients who developed VLST after DES implantation. These results were compared to those in 57?patients with neointimal hyperplasia causing?>40% diameter stenosis. Lipid-laden neointima was defined as a region with marked signal attenuation and a diffuse border. Four (22.2%) of 18 patients with VLST had ruptured and lipid-laden neointima inside DESs without uncovered or malapposed stent struts. In the remaining 14 patients who developed VLST without neointimal rupture, uncovered and malapposed struts were observed in nine and seven patients, respectively, and lipid-laden neointima in four patients. Lipid-laden neointima was more frequently observed in four patients with neointimal rupture than in 14 patients without neointimal rupture (100% vs. 28.6%, respectively, P?=?0.023). Of 57 patients with neointimal hyperplasia, eight (14.0%) had lipid-laden neointima. Time to OCT study after DES implantation was significantly longer in the eight patients with lipid-laden neointima than in 49 patients without lipid-laden neointima (45.5?±?17.7?months vs. 11.7?±?7.2?months, respectively, P?<?0.001). Lipid-laden neointima was detected in some patients with neointimal hyperplasia?>?1?year after DES implantation. In addition to uncovered or malapposed struts, rupture of lipid-laden neointima inside DESs was identified in some patients with DES-related VLST.     

Intravascular imaging comparison of two metallic limus-eluting stents abluminally coated with biodegradable polymers: IVUS and OCT results of the DESTINY trial

We sought to compare, by means of IVUS and OCT imaging, the performance of a novel sirolimus-eluting drug-eluting stent (DES) with biodegradable polymer (Inspiron?) to the Biomatrix? DES. From the DESTINY trial, a total of 70 randomized patients (2:1) were enrolled in the IVUS substudy (Inspiron?, n?=?46; Biomatrix?: n?=?20) while 25 patients were evaluated with OCT (Inspiron?, n?=?19; Biomatrix?: n?=?06) at 9-month follow-up. The main endpoints were % of neointimal tissue obstruction (IVUS) and neointimal stut coverage (OCT) at 9 months. Patients treated with both DES had very little NIH formation at 9 months either by IVUS (% of NIH obstruction of 4.9?±?4.1?% with Inspiron? vs. 2.7?±?2.9?% with Biomatrix?, p?=?0.03) or by OCT (neointimal thickness of 144.2?±?72.5 µm Inspiron? vs. 115.0?±?53.9 µm with Biomatrix?, p?=?0.45). Regarding OCT strut-level assessment, again both devices showed excellent 9-month performance, with high rates of strut coverage (99.49?±?1.01?% with Inspiron? vs. 97.62?±?2.21?% with Biomatrix?, p?<?0.001) and very rare malapposition (0.29?±?1.06?% with Inspiron? vs. 0.53?±?0.82?% with Biomatrix?, p?=?0.44). Patients with any uncovered struts were more frequently identified in the Biomatrix? group (9.78?±?7.13 vs. 2.29?±?3.91?%, p?<?0.001). In the present study, midterm IVUS and OCT evaluations showed that both new generation DES with biodegradable polymer were effective in terms of suppressing excessive neointimal response, with very high rates of apposed and covered struts, suggesting a consistent and benign healing pattern.     

Fusion of optical coherence tomographic and angiographic data for more accurate evaluation of the endothelial shear stress patterns and neointimal distribution after bioresorbable scaffold implantation: comparison with intravascular ultrasound-derived reconstructions

Intravascular ultrasound (IVUS)-based reconstructions have been traditionally used to examine the effect of endothelial shear stress (ESS) on neointimal formation. The aim of this analysis is to compare the association between ESS and neointimal thickness (NT) in models obtained by the fusion of optical coherence tomography (OCT) and coronary angiography and in the reconstructions derived by the integration of IVUS and coronary angiography. We analyzed data from six patients implanted with an Absorb bioresorbable vascular scaffold that had biplane angiography, IVUS and OCT investigation at baseline and 6 or 12 months follow-up. The IVUS and OCT follow-up data were fused separately with the angiographic data to reconstruct the luminal morphology at baseline and follow-up. Blood flow simulation was performed on the baseline reconstructions and the ESS was related to NT. In the OCT-based reconstructions the ESS were lower compared to the IVUS-based models (1.29 ± 0.66 vs. 1.87 ± 0.66 Pa, P = 0.030). An inverse correlation was noted between the logarithmic transformed ESS and the measured NT in all the OCT-based models which was higher than the correlation reported in five of the six IVUS-derived models (?0.52 ± 0.19 Pa vs. ?0.10 ± 0.04, P = 0.028). Fusion of OCT and coronary angiography appears superior to IVUS-based reconstructions; therefore it should be the method of choice for the study of the effect of the ESS on neointimal proliferation.     

Early vascular healing after titanium–nitride–oxide-coated stent versus platinum–chromium everolimus-eluting stent implantation in patients with acute coronary syndrome

Data on early vascular healing response of novel stent designs are scarce. In this randomized prospective trial, we sought to compare early neointimal coverage of cobalt–chromium-based titanium–nitride–oxide-coated bioactive stents (CoCr-BAS) versus platinum–chromium everolimus-eluting stents (PtCr-EES) at 2-month follow-up in patients with acute coronary syndrome (ACS). Forty patients with ACS were randomized to receive either CoCr-BAS (n?=?19) or PtCr-EES (n?=?21). Neointimal strut coverage and strut apposition were examined by optical coherence tomography; and coronary flow reserve (CFR), fractional flow reserve (FFR) and index of microcirculatory resistance (IMR) were assessed using a coronary pressure wire at 2 months. Two patients in the PtCr-EES underwent OCT out of the time frame of the study, and were excluded from analysis. At 63?±?8 days, 302 cross-sections (3412 struts) were analysed in the CoCr-BAS group, and 324 cross-sections (3460 struts) in the PtCr-EES group. Median [IQR] neointimal thickness was 203 [108] µm and 42.2 [41] µm for CoCr-BAS and PtCr-EES, respectively (p?<?0.001). Median [IQR] percentage of uncovered struts was 1.2 [2.8] % versus 11.3 [17.7] %, respectively (p?<?0.001). Flow measurements were comparable between the two groups (p?>?0.05 for all). CoCr-BAS showed earlier and more adequate neointimal coverage of struts at 2 months, compared with PtCr-EES, but with more neointimal hyperplasia. Functional healing as assessed by CFR, FFR, and IMR was similar between the two stent arms.     

Healing score of the Xinsorb scaffold in the treatment of de novo lesions: 6-month imaging outcomes

The objectives of this study are to assess the healing score (HS) and neointimal thickness of the Xinsorb scaffold, and explore the relationships between the implanted patterns, neointimal thickness, and HS. The Xinsorb bioresorbable sirolimus-eluting scaffold is the first domestically designed and fabricated bioresorbable scaffold in China. The 6-month follow-up found it to be safe and effective in the treatment of single de novo coronary lesions. The Xinsorb scaffolds were implanted in 30 patients with symptomatic ischemic coronary disease. A 6-month follow-up was performed in a subset of 19 patients; the HS and neointimal thickness were evaluated by optical coherence tomography. Struts were classified as ApposedCovered, ApposedUncovered, MalapposedCovered, MalapposedUncovered, jailing and presence of intraluminal masses. The implanted pressure, implanted duration, and post-expansion pressure were recorded during the operation. We evaluated the relationship between the HS or neointimal thickness and the implanted pressure, holding time, and post-expansion pressure. The device and procedure success rates were both 100%. No major adverse cardiac or scaffold-thrombus related events occurred. At 6 months, 12,295 struts were analyzed to determine the HS (6.23) and neointimal thickness (0.1021?±?0.05718 mm) in the Xinsorb scaffolds. There was a strong negative relationship between the HS and the implantation duration (Pearson r = ? 0.518, p?=?0.023). A significant negative relationship also existed between the HS and post-dilatation (Pearson r = ? 0.631, p?=?0.004). The Xinsorb scaffold HS appears negative correlated with the implanted duration and post-dilatation. We will further evaluate the HS of randomized controlled trial of the Xissorb scaffold.     

Comparative assessment of three drug eluting stents with different platforms but with the same biodegradable polymer and the drug based on quantitative coronary angiography and optical coherence tomography at 12-month follow-up

The aim of this study was to compare neointima proliferation in three drug-eluting stents (DES) produced by the same company (Balton, Poland) which are covered with a biodegradable polymer and elute sirolimus (concentration: 1.0 and 1.2 µg/mm²), but have different stent platforms and strut thickness: stainless steel Prolim^® (115 µm) and BiOSS LIM^® (120 µm) and cobalt-chromium Alex^® (70 µm). We analyzed data of patients with quantitative coronary angiography (QCA) and optical coherence tomography (OCT) at 12 months from BiOSS LIM Registry, Prolim Registry and Alex OCT clinical trial. There were 56 patients enrolled, in whom 29 Prolim^® stents were deployed, in 11—BiOSS LIM^® and in 16—Alex stents. The late lumen loss was the smallest in Prolim^® subgroup (0.26?±?0.17 mm) and did not differ from Alex^® subgroup (0.28?±?0.47 mm). This parameter was significantly bigger in BiOSS^® subgroup (0.38?±?0.19 mm; p?<?0.05). In OCT analysis there was no statistically significant difference between Prolim^® and Alex^® subgroups in terms of mean neointima burden (24.6?±?8.6 vs. 19.27?±?8.11%) and neointima volume (28.16?±?15.10 vs. 24.51?±?17.64 mm³). In BiOSS^® group mean neointima burden (30.9?±?6.2%) and mean neointima volume (44.9?±?4.9 mm³) were significantly larger. The morphological analysis revealed that in most cases in all groups the neointima was homogenous with plaque presence only around stent struts. In the QCA and OCT analysis regular DES (Prolim^® and Alex^®) obtained similar results, whereas more pronounced response from the vessel wall was found in the BiOSS^® subgroup.     

Neointimal coverage and vasodilator response to titanium-nitride-oxide-coated bioactive stents and everolimus-eluting stents in patients with acute coronary syndrome: insights from the BASE-ACS trial

Incomplete stent endothelialization is associated with late and very late stent thrombosis. In a post hoc analysis of the BASE-ACS trial, we sought to assess neointimal coverage and coronary flow reserve (CFR) 9 months after implantation of titanium-nitride-oxide-coated bioactive stents (BAS) versus everolimus-eluting stents (EES) in patients with acute coronary syndrome (ACS). In the BASE-ACS trial, 827 patients with ACS were randomized to receive either BAS or EES. In the current study, we examined neointimal growth and strut coverage by optical coherence tomography and CFR by trans-thoracic echocardiography in 28 consecutive non-diabetic patients with the culprit lesion in the left anterior descending coronary artery. The primary endpoints were binary stent strut coverage and CFR at 9-month follow-up. A total of 13 patients were included in the BAS group (2,033 struts); 15 in the EES group (2,898 struts). Binary stent strut coverage was higher and malapposed struts lower with BAS versus EES (99.4 vs 89.2, and 0.2 vs 4.6 %, respectively, p < 0.001 for both). Neointimal hyperplasia thickness was greater with BAS versus EES (274.2 vs 100.1 μm, respectively, p < 0.001). CFR was lower with EES versus BAS (2.2 ± 0.8 vs 3.0 ± 0.5, respectively, p = 0.001). Abnormal CFR (<2.5) were detected in 10 patients in the EES group versus one in the BAS group (p = 0.002). The current study demonstrated that in patients with ACS, BAS resulted in improved neointimal stent strut coverage and better coronary vasodilator function as compared with EES at 9-month follow-up.     

Inhibition of neointimal proliferation after bare metal stent implantation with low-pressure drug delivery using a paclitaxel-coated balloon in porcine coronary arteries

A variety of mechanical and laser-based methods remove or shift atherosclerotic plaques and reopen the artery to its original lumen. Subsequent treatment with drug-coated balloons (DCB) may smooth the vessel wall but does not require high-pressure inflation. We investigated the efficacy of paclitaxel-coated balloons inflated with only 2 atm after bare metal stent implantation in coronary arteries of 24 pigs. Angiography and histomorphometry was performed on day 28. DCB inflated with 2 atm caused similar reduction of late lumen loss (LLL) as high-pressure inflation with 12 atm (0.89 ± 0.58 vs. 0.72 ± 0.39 mm, p = 0.34). Both DCB treatments significantly (p < 0.01) reduced LLL versus uncoated balloons (1.50 ± 0.51 mm). Treatment with low-pressure DCB resulted in less maximal intimal thickness (0.45 ± 0.15 vs. 0.67 ± 0.25 mm) and neointimal area (2.93 ± 0.73 vs. 3.82 ± 1.27 mm²) than treatment with uncoated balloons (p < 0.05). In conclusion, low-pressure treatment with DCB was similarly effective as high-pressure treatment justifying clinical trials in vessels which will benefit from inhibition of neointimal proliferation but may not tolerate high inflation pressure.     

Paclitaxel-coated balloon treatment for functionally nonsignificant residual coronary lesions after balloon angioplasty

There is limited data on the efficacy of paclitaxel-coated balloon (PCB) compared to stents for de novo coronary lesions. The purpose of this study was to compare the efficacy of PCB treatment with stent implantation for de novo coronary lesions after successful plain old balloon angioplasty (POBA) guided by fractional flow reserve (FFR). In 200 patients scheduled for elective percutaneous coronary intervention (PCI) for de novo lesions, FFR was measured after POBA (POBA–FFR). If POBA–FFR was ≥?0.75, patients were treated with PCB (PCB group, n?=?78) or stent (Stent group, n?=?73). If POBA–FFR was <?0.75, stent was implanted as planned (Reference group, n?=?42). The primary endpoint was late lumen loss at 9 months and the secondary endpoint was adverse cardiac events (cardiac death, myocardial infarction, target lesion thrombosis, or repeat revascularization) at 12 months follow-up. There was no between-group differences in the POBA–FFR (0.87?±?0.05 in PCB, 0.89?±?0.06 in stent, p?=?0.101). At 9 months, late lumen loss was significantly lower in the PCB group compared to the Stent group (0.05?±?0.33 vs. 0.59?±?0.76 mm, p?<?0.001). Adverse cardiac events were not different between the PCB, Stent and Reference groups (2.6, 5.5, and 9.5% respectively; p?=?0.430 for PCB vs. Stent group; p?=?0.229 for the reference vs. both other groups). PCB treatment guided by POBA–FFR showed excellent 9 months angiographic and functional results, as well as comparable 12 months clinical outcomes, compared with stent implantation for de novo coronary lesions.     

Early detection of left ventricular diastolic dysfunction using conventional and speckle tracking echocardiography in a large animal model of metabolic dysfunction

Left ventricular (LV) diastolic dysfunction is one of the important mechanisms responsible for symptoms in patients with heart failure. The aim of the current study was to identify parameters that may be used to detect early signs of LV diastolic dysfunction in diabetic pigs on a high fat diet, using conventional and speckle tracking echocardiography. The study population consisted of 16 healthy Göttingen minipigs and 18 minipigs with experimentally induced metabolic dysfunction. Echocardiography measurements were performed at baseline and 3-month follow-up. The ratio of peak early (E) and late filling velocity (E/A ratio) and the ratio of E and the velocity of the mitral annulus early diastolic wave (E/Em ratio) did not change significantly in both groups. Peak untwisting velocity decreased in the metabolic dysfunction group (? 30.1?±?18.5 vs. ? 23.4?±?15.5 °/ms) but not in controls (? 38.1?±?23.6 vs. ? 42.2?±?23.0 °/ms), being significantly different between the groups at the 3-month time point (p?<?0.05). In conclusion, whereas E/A ratio and E/Em ratio did not change significantly after 3 months of metabolic dysfunction, peak untwisting velocity was significantly decreased. Hence, peak untwisting velocity may serve as an important marker to detect early changes of LV diastolic dysfunction.     

Assessment of an asymmetrical coating stent with sirolimus released from ablumial matrix in porcine model

Background

Delayed endothelialization contributes to stent thrombosis of current drug-eluting stents. The asymmetrical coating technique provides an anti-proliferative effect abluminally without affecting luminal endothelialization. Layer-by-layer self-assembled chitosan/heparin (C/H LBL) has been proved to promote re-endothelialization. A novel stent system, C/H LBL coated luminally and sirolimus released abluminally (C/H LBL-SES), was fabricated.

Methods

Bare metal stents (BMS), traditionally circumferential sirolimus-eluting stents (SES), and C/H LBL-SES were implanted into porcine coronary arteries. At the 7, 14 and 28?days follow-up (FU), angiography, intravascular ultrasound (IVUS), vasomotor function induced by acetylcholine (Ach), scanning-electron microscopy and histopathology were performed. Remodeling index (RI) was based on IVUS and defined as cross-sectional area (CSA) of vessel at in-stent segment divided by CSA of reference vessel and expressed as a percentage with a normal range from 0.95 to 1.05.

Results

Thirty-eight mini pigs were enrolled and 74 stents (BMS?=?23, C/H LBL?=?28, SES?=?23) were implanted in this study. At 28?days after implantation, the diameter stenosis of C/H LBL-SES by quantitative coronary angiography was 18.8?±?2.5?%, the area stenosis by histomorphometry was 24.2?±?2.9?%, which were comparable to that of SES and superior to BMS. At 14?days, re-endothelialization of C/H LBL-SES was almost completed, while only about 50?% of surface of SES was covered by endothelium. At 7, 14 and 28?days FU, although C/H LBL-SES suffered a greater vasoconstriction induced by Ach infusion than BMS (P?<?0.05), it behaved better than SES (P?<?0.01). No sign of stent malapposition was detected, while RI was within the normal range by IVUS. No acute or subacute thrombotic events occurred in all three groups.

Conclusions

The asymmetrically designed C/H LBL-SES successfully inhibited neointima hyperplasia, while diminishing vasoconstriction after Ach-stress. Endothelialization of C/H LBL-SES was less affected compared with traditionally circumferentially coated SES.     

雷帕霉素洗脱支架与紫杉醇洗脱支架在急性心肌梗死直接经皮冠状动脉介入治疗中的疗效比较

目的 比较雷帕霉素洗脱支架(Firebird)与紫杉醇洗脱支架(Coroflex)在急性ST段抬高型心肌梗死直接经皮冠状动脉介入治疗中的有效性和安全性.方法 连续入选220例急性ST段抬高型心肌梗死患者,随机分入Firebird组(112例)和Coroflex组(108例),分析患者冠状动脉的靶血管特点、手术成功率及术后随访情况.主要终点为术后12个月主要不良心脏事件(包括死亡、心肌梗死和靶血管重建),次要终点为9个月晚期管腔丢失和支架内再狭窄.结果 手术成功率100％;术后9个月冠状动脉造影随访Firebird组与Coroflex组支架内晚期管腔丢失和支架内再狭窄的发生率差异无统计学意义(P＞0.05);术后12个月Firebird组和Coroflex组死亡(2.7％ vs 1.8％,P＞0.05)、心肌梗死(2.7％ vs 1.8％,P＞0.05)、靶血管重建(2.7％ vs 2.8％,P＞0.05)、主要不良心脏事件(4.5％ vs3.7％,P ＞0.05)及支架内血栓形成(2.7％ vs 1.8％,P＞0.05)的发生率差异均无统计学意义.结论 Firebird支架与Coroflex支架在直接经皮冠状动脉介入治疗急性ST段抬高型心肌梗死中的近期疗效和安全性是一致的.     

Long-term (≥2 years) follow-up optical coherence tomographic study after sirolimus- and paclitaxel-eluting stent implantation: comparison to 9-month follow-up results

Many studies have demonstrated that late or very late thrombosis after drug-eluting stent (DES) implantation may be related with incomplete neointimal coverage. We investigated long-term (≥2 years) results of neointimal coverage following sirolimus-eluting stent (SES) and paclitaxel-eluting stent (PES) implantation using optical coherence tomography (OCT). A follow-up angiography with OCT examination was performed in 29 patients with 32 lesions for more than 2 years (group 1; 1,066 ± 381 days) and 101 patients with 104 lesions at 9 months (group 2; 273 ± 33 days) after the index procedure. The status of neointimal coverage and stent apposition was evaluated. The number of stents with completely covered struts was higher (25.0% in group 1 vs. 13.5% in group 2, P = 0.12). The percentage of uncovered struts (5.4 ± 7.5% in group 1 vs. 8.5 ± 11.6% in group 2, P = 0.19) and that of malapposed strut (0.5 ± 1.4% vs. 1.5 ± 4.2%, respectively, P = 0.19) were lower in group 1. While the percentage of uncovered and malapposed struts were quite similar in the PES groups between the two groups (P = 0.54 and 0.65, respectively), there were lower trends in the percentage of uncovered and malapposed struts in the SES group (P = 0.09 and 0.09, respectively). In conclusion, incomplete neointimal coverage was still observed in a majority of DESs and considerable struts were not covered with neointima even at more than 2 years after DES implantation. The pattern of neointimal coverage between 9-month and 2-year appeared to be somewhat different between PES and SES.