Stent-specific fat attenuation index is associated with target vessel revascularization after PCI.

OBJECTIVES: To explore the clinical relevance of stent-specific perivascular fat attenuation index (FAI) in patients with stent implantation. METHODS: A total of 162 consecutive patients who underwent coronary computed tomography angiography (CCTA) following stent implantation were retrospectively included. The stent-specific FAI at 2 cm adjacent to the stent edge was calculated. The endpoints were defined as target vessel revascularization (TVR) on the stented vessel after CCTA and readmission times due to chest pain after stent implantation. Binary logistic regression analysis for TVR and ordinal regression models were conducted to identify readmission times (0, 1, and ≥ 2) with generalized estimating equations on a per-stent basis. RESULTS: On a per-stent basis, 9 stents (4.5%) experienced TVR after PCI at a median 30 months' follow-up duration. Stent-specific FAI differed significantly among subgroups of patients with stent implantation and different readmission times (p = 0.002); patients with at least one readmission had higher stent-specific FAI than those without readmission (p < 0.001). Bifurcated stents (odds ratio [OR]: 11.192, p = 0.001) and stent-specific FAI (OR: 1.189, p = 0.04) were independently associated with TVR. With no readmission as a reference, stent-specific FAI (OR: 0.984, p = 0.007) was an independent predictor for hospital readmission times ≥ 2 (p = 0.003). CONCLUSION: Non-invasive stent-specific FAI derived from CCTA was found to be associated with TVR, which was a promising imaging marker for functional assessment in patients who underwent stent implantation. CLINICAL RELEVANCE STATEMENT: Noninvasive fat attenuation index adjacent to the stents edge derived from CCTA, an imaging marker reflecting the presence of inflammation acting on the neointimal tissue at the sites of coronary stenting, might be relevant clinically with target vessel revascularization. KEY POINTS: • Non-invasive stent-specific FAI derived from CCTA was associated with TVR (OR: 1.189 [95% CI: 1.007-1.043], p = 0.04) in patients who underwent stent implantation. • Stent-specific FAI significantly differed among a subgroup of patients with chest pain after stent implantation and with different readmission times (p = 0.002); the patients with at least one readmission had higher stent-specific FAI than those without readmission (p < 0.001). • Non-invasive stent-specific FAI derived from CCTA could be used as an imaging maker for the functional assessment of patients following stent implantation.

Prediction value of pericoronary fat attenuation index for coronary in-stent restenosis.

OBJECTIVES: As a novel imaging marker, pericoronary fat attenuation index (FAI) reflects the local coronary inflammation which is one of the major mechanisms for in-stent restenosis (ISR). We aimed to validate the ability of pericoronary FAI to predict ISR in patients undergoing percutaneous coronary intervention (PCI). MATERIALS AND METHODS: Patients who underwent coronary CT angiography (CCTA) before PCI within 1 week between January 2017 and December 2019 at our hospital and had follow-up invasive coronary angiography (ICA) or CCTA were enrolled. Pericoronary FAI was measured at the site where stents would be placed. ISR was defined as ≥ 50% diameter stenosis at follow-up ICA or CCTA in the in-stent area. Multivariable analysis using mixed effects logistic regression models was performed to test the association between pericoronary FAI and ISR at lesion level. RESULTS: A total of 126 patients with 180 target lesions were included in the study. During 22.5 months of mean interval time from index PCI to follow-up ICA or CCTA, ISR occurred in 40 (22.2%, 40/180) stents. Pericoronary FAI was associated with a higher risk of ISR (adjusted OR = 1.12, p = 0.028). The optimum cutoff was - 69.6 HU. Integrating the dichotomous pericoronary FAI into current state of the art prediction model for ISR improved the prediction ability of the model significantly (△area under the curve = + 0.064; p = 0.001). CONCLUSION: Pericoronary FAI around lesions with subsequent stent placement is independently associated with ISR and could improve the ability of current prediction model for ISR. CLINICAL RELEVANCE STATEMENT: Pericoronary fat attenuation index can be used to identify the lesions with high risk for in-stent restenosis. These lesions may benefit from extra anti-inflammation treatment to avoid in-stent restenosis. KEY POINTS: • Pericoronary fat attenuation index reflects the local coronary inflammation. • Pericoronary fat attenuation index around lesions with subsequent stents placement can predict in-stent restenosis. • Pericoronary fat attenuation index can be used as a marker for future in-stent restenosis.

Matrix-Binding, N-Cadherin-Targeting Chimeric Peptide Inhibits Intimal Thickening but Not Endothelial Repair in Balloon-Injured Carotid Arteries.

BACKGROUND: Treatment of occluded vessels can involve angioplasty, stenting, and bypass grafting, which can be limited by restenosis and thrombosis. Drug-eluting stents attenuate restenosis, but the current drugs used are cytotoxic, causing smooth muscle cell (SMC) and endothelial cell (EC) death that may lead to late thrombosis. N-cadherin is a junctional protein expressed by SMCs, which promotes directional SMC migration contributing to restenosis. We propose that engaging N-cadherin with mimetic peptides can act as a cell type-selective therapeutic strategy to inhibit polarization and directional migration of SMCs without negatively impacting ECs. METHODS: We designed a novel N-cadherin-targeting chimeric peptide with a histidine-alanine-valine cadherin-binding motif, combined with a fibronectin-binding motif from Staphylococcus aureus. This peptide was tested in SMC and EC culture assays of migration, viability, and apoptosis. Rat carotid arteries were balloon injured and treated with the N-cadherin peptide. RESULTS: Treating scratch-wounded SMCs with the N-cadherin-targeting peptide inhibited migration and reduced polarization of wound-edge cells. The peptide colocalized with fibronectin. Importantly, EC junction, permeability, or migration was not impacted by peptide treatment in vitro. We also demonstrated that the chimeric peptide persisted for 24 hours after transient delivery in the balloon-injured rat carotid artery. Treatment with the N-cadherin-targeting chimeric peptide reduced intimal thickening in balloon-injured rat carotid arteries at 1 and 2 weeks after injury. Reendothelialization of injured vessels after 2 weeks was unimpaired by peptide treatment. CONCLUSIONS: These studies show that an N-cadherin-binding and fibronectin-binding chimeric peptide is effective in inhibiting SMC migration in vitro and in vivo and limiting neointimal hyperplasia after balloon angioplasty without affecting EC repair. These results establish the potential of an advantageous SMC-selective strategy for antirestenosis therapy.

Comparative efficacy of drug-eluting balloon and drug-eluting stent for treatment of in-stent restenosis: a systematic review and meta-analysis.

OBJECTIVE: To compare the efficacy of drug-eluting stents and drug-eluting balloons in treating in-stent restenosis. METHODS: The systematic review was conducted from January to February 2022, and comprised literature search on PubMed, ProQuest, Cochrane Library and Google Scholar databases with relevant key words to locate randomised controlled trials and observational studies published between 2000 and 2022 that compared drugeluting balloons and drug-eluting stents in the treatment of in-stent restenosis. The outcomes were all-cause death, cardiovascular death, major adverse cardiovascular events, myocardial infarction, stent thrombosis, stroke and target vessel revascularisation. The pooled risk ratio for each outcome was analysed. Data was analysed using Review Manager 5.1. RESULTS: Of the 1,105 studies identified, 11(0.99%) were analysed in detail; 7(63.6%) randomised controlled trials and 4(36.4%) observational studies. There were 2,437 patients with in-stent restenosis. There was no significant difference between drug-eluting balloons and drugeluting stents with respect to all-cause death, cardiovascular death, stroke, stent thrombosis, myocardial infarction and major adverse cardiovascular events (p>0.05). Drug-eluting stents significantly caused more target vessel revascularisation compared to drugeluting balloons (p=0.004). CONCLUSIONS: Except for target vessel revascularisation, the drug-eluting balloons and drug-eluting stents had no difference in terms of clinical outcomes related to in-stent restenosis patients.

Management of Restenosis after Stenting in Left Main Coronary Artery Disease.

Background: The optimal alternative treatment strategy to coronary artery bypass graft surgery (CABG) for in-stent restenosis (ISR) in left main (LM) coronary artery disease remains uncertain. Methods: We retrospectively screened all intervention reports from an intervention database and extracted those mentioning an LM stent. We then manually confirmed reports involving LM ISR and divided them into two groups, those in which the patient received a new drug-eluting stent (new-DES) strategy, and those in which the patient received a drug-coated balloon (DCB) only. A composite endpoint of major adverse cardiovascular events (MACEs) and each individual endpoint were compared. We also performed a brief analysis of similar designed studies. Results: Between the new-DES (n = 40) and DCB-only (n = 22) groups, during median respective follow-up times of 581.5 and 642.5 days, no significant statistical differences were detected in MACEs (50.0% vs. 50.0%, p = 0.974), cardiovascular death (27.5% vs. 13.6%, p = 0.214), nonfatal myocardial infarction (30.0% vs. 31.8%, p = 0.835), or target lesion revascularization (35.0% vs. 45.5%, p = 0.542). We analyzed four similar studies and found comparable MACE findings (odds ratio: 0.85, 95% CI: 0.44-1.67). Conclusions: Our findings support both DCB angioplasty and repeat DES implantation for LMISR lesions in patients who were clinically judged to be unsuitable for CABG; the treatments achieved comparable clinical results in terms of MACEs in the medium term.

Is coronary artery tortuosity a predisposing factor for drug-eluting stent restenosis?

BACKGROUND: Coronary artery tortuosity (CAT) is a relatively common finding on coronary angiography and may be associated with impaired left ventricular relaxation and coronary ischemia However, the significance of CAT remains unknown. This study aimed to investigate whether the severity of tortuosity in the targeted coronary segment is a predictor of stent restenosis. METHODS: The study included a total of 637 patients undergoing drug-eluting stent implantation due to stable or unstable angina and who had no native coronary artery stenosis on their last coronary angiogram. The patients were separated into two groups: 312 patients with in-stent restenosis and 325 patients without in-stent restenosis. All patients underwent computed tomography (CT) coronary angiography after invasive angiography and CAT was calculated using the computer software. RESULTS: Patients with in-stent restenosis had higher CAT than those without restenosis (1.25 ± 0.11 vs. 1.11 + 0.07, p < 0.001). Multivariate Cox regression analysis showed that the tortuosity index (hazard ratio [HR]: 1.246 95% confidence interval [CI]: 1.127-1.376 p < 0.001) and the circumflex lesion (HR: 1.437 95% CI: 1.062-1.942 p = 0.019) were independently associated with in-stent restenosis. With the threshold value of severe tortuosity set at 1.15, the prediction of could be made with 81% sensitivity and 80% specificity. CONCLUSION: The severity of tortuosity is proportional to coronary in-stent stenosis in patients with stable and unstable angina pectoris undergoing drug-eluting stent implantation for a severe single coronary artery.

Combined use of intravascular lithotripsy and brachytherapy: A new approach for the treatment of recurrent coronary in-stent restenosis.

Treatment of coronary in-stent restenosis (ISR) is challenging and often requires combination of multiple treatment modalities. Coronary intravascular lithotripsy (IVL) has been successfully used for treating stent under-expansion, but is not currently commercially available in the United States. We present three recurrent coronary ISR cases in which multiple treatment modalities (high-pressure balloon inflation, plaque modification balloons, and laser with contrast injection) failed. These patients were treated with a combination of IVL (peripheral IVL catheter used off-label in the coronary arteries) and brachytherapy. Due to the high IVL balloon profile, delivery via femoral or radial access was challenging, requiring 7-8 French guide catheters. IVL was performed delivering 4-8 treatments of 20 pulses each with a favorable final angiographic and intravascular ultrasound result. All patients were angina free 1 month after the procedure.

Feasibility and prognostic role of machine learning-based FFRCT in patients with stent implantation.

OBJECTIVES: To investigate the feasibility and prognostic implications of coronary CT angiography (CCTA) derived fractional flow reserve (FFRCT) in patients who have undergone stents implantation. METHODS: Firstly, the feasibility of FFRCT in stented vessels was validated. The diagnostic performance of FFRCT in identifying hemodynamically in-stent restenosis (ISR) in 33 patients with invasive FFR ≤ 0.88 as reference standard, intra-group correlation coefficient (ICC) between FFRCT and FFR was calculated. Secondly, prognostic value was assessed with 115 patients with serial CCTA scans after PCI. Stent characteristics (location, diameter, length, etc.), CCTA measurements (minimum lumen diameter [MLD], minimum lumen area [MLA], ISR), and FFRCT measurements (FFRCT, ΔFFRCT, ΔFFRCT/stent length) both at baseline and follow-up were recorded. Longitudinal analysis included changes of MLD, MLA, ISR, and FFRCT. The primary endpoint was major adverse cardiovascular events (MACE). RESULTS: Per-patient accuracy of FFRCT was 0.85 in identifying hemodynamically ISR. FFRCT had a good correlation with FFR (ICC = 0.84). 15.7% (18/115) developed MACE during 25 months since follow-up CCTA. Lasso regression identified age and follow-up ΔFFRCT/length as candidate variables. In the Cox proportional hazards model, age (hazard ratio [HR], 1.102 [95% CI, 1.032-1.177]; p = 0.004) and follow-up ΔFFRCT/length (HR, 1.014 [95% CI, 1.006-1.023]; p = 0.001) were independently associated with MACE (c-index = 0.856). Time-dependent ROC analysis showed AUC was 0.787 (95% CI, 0.594-0.980) at 25 months to predict adverse outcome. After bootstrap validation with 1000 resamplings, the bias-corrected c-index was 0.846. CONCLUSIONS: Noninvasive ML-based FFRCT is feasible in patients following stents implantation and shows prognostic value in predicting adverse events after stents implantation in low-moderate risk patients. KEY POINTS: • Machine-learning-based FFRCT is feasible to evaluate the functional significance of in-stent restenosis in patients with stent implantation. • Follow-up △FFRCT along with the stent length might have prognostic implication in patients with stent implantation and low-to-moderate risk after 2 years follow-up. The prognostic role of FFRCT in patients with moderate-to-high or high risk needs to be further studied. • FFRCT might refine the clinical pathway of patients with stent implantation to invasive catheterization.

Is a covered stent justifiable in the treatment of coronary artery perforation? An observational analysis of long-term results of two different covered stent types.

OBJECTIVES: In this retrospective observational study, we investigate outcome of patients treated with or without covered stent (CS) implantation in the management of coronary artery perforation (CAP) during coronary intervention. BACKGROUND: CSs have shown to be effective devices to achieve acute hemostasis in large CAP. However, doubts have been raised regarding their long-term outcome. METHODS: Data of 19 061 PCI procedures during a 10-year period were reviewed. Fifty-five cases of large CAP were withheld (Ellis type 2, 3 or cavity spilling). All medical and procedural records of these cases were retrospectively reviewed. RESULTS: Twenty-four (43.6%) patients were treated with CS implantation (15 polytetrafluoroethylene and 9 pericardium CSs). Twenty-six (47.3%) patients were managed without CS implantation, of whom five had unsuccessful delivery of a CS (stent delivery failure 17.2%). Although significantly more Ellis type-3 perforations were present in the CS group compared to the Non-CS group (75.0% vs 45.2%; P = 0.03), in-hospital mortality was not significantly different (8.3% vs 6.4%; [P = 0.79]). We observed a high rate of CS restenosis (29.2%) but a lower rate of CS thrombosis (4.2%). Despite these observations, 5-year MACE and all-cause mortality were not significantly different between CS and Non-CS group (respectively, 58.8% vs 50.0% (P = 0.26) and 26.7% vs 13.3% (P = 0.36)). CONCLUSION: Although deliverability of CSs was not flawless and a high rate of CS restenosis appeared, short- and long-term outcome were comparable between patients treated with or without CS. Therefore, CSs are justifiable in the treatment of CAP.

Interferon Regulatory Factor 4 Inhibits Neointima Formation by Engaging Krüppel-Like Factor 4 Signaling.

BACKGROUND: The mechanisms underlying neointima formation remain unclear. Interferon regulatory factors (IRFs), which are key innate immune regulators, play important roles in cardiometabolic diseases. However, the function of IRF4 in arterial restenosis is unknown. METHODS: IRF4 expression was first detected in human and mouse restenotic arteries. Then, the effects of IRF4 on neointima formation were evaluated with universal IRF4-deficient mouse and rat carotid artery injury models. We performed immunostaining to identify IRF4-expressing cells in the lesions. Smooth muscle cell (SMC)-specific IRF4-knockout (KO) and -transgenic (TG) mice were generated to evaluate the effects of SMC-IRF4 on neointima formation. We used microarray, bioinformatics analysis, and chromatin immunoprecipitation assay to identify the downstream signals of IRF4 and to verify the targets in vitro. We compared SMC-IRF4-KO/Krüppel-like factor 4 (KLF4)-TG mice with SMC-IRF4-KO mice and SMC-specific IRF4-TG/KLF4-KO mice with SMC-specific IRF4-TG mice to investigate whether the effect of IRF4 on neointima formation is KLF4-dependent. The effect of IRF4 on SMC phenotype switching was also evaluated. RESULTS: IRF4 expression in both the human and mouse restenotic arteries is eventually downregulated. Universal IRF4 ablation potentiates neointima formation in both mice and rats. Immunostaining indicated that IRF4 was expressed primarily in SMCs in restenotic arteries. After injury, SMC-IRF4-KO mice developed a thicker neointima than control mice. This change was accompanied by increased SMC proliferation and migration. However, SMC-specific IRF4-TG mice exhibited the opposite phenotype, demonstrating that IRF4 exerts protective effects against neointima formation. The mechanistic study indicated that IRF4 promotes KLF4 expression by directly binding to its promoter. Genetic overexpression of KLF4 in SMCs largely reversed the neointima-promoting effect of IRF4 ablation, whereas ablation of KLF4 abolished the protective function of IRF4, indicating that the protective effects of IRF4 against neointima formation are KLF4-dependent. In addition, IRF4 promoted SMC dedifferentiation. CONCLUSIONS: IRF4 protects arteries against neointima formation by promoting the expression of KLF4 by directly binding to its promoter. Our findings suggest that this previously undiscovered IRF4-KLF4 axis plays a key role in vasculoproliferative pathology and may be a promising therapeutic target for the treatment of arterial restenosis.

Effect of diabetes mellitus on long-term outcomes after repeat drug-eluting stent implantation for in-stent restenosis.

BACKGROUND: Whether diabetes mellitus (DM) is a predictor of long-term adverse clinical outcomes after repeat drug eluting stent (DES) implantation for DES in-stent restenosis (ISR) remains controversial. We sought to evaluate the effect of DM on the long-term clinical outcomes in patients undergoing repeat DES implantation for DES-ISR lesions. METHODS: In the present study, 254 patients with DES-ISR were divided into DM or non-DM groups according to the presence or absence of DM. All patients received repeat 2nd generation DES implantation for DES-ISR. The occurrences of major adverse cardiac events (MACEs) over a 2-year follow-up period were compared between the two groups. MACEs were defined as cardiac death, myocardial infarction (MI), and target lesion revascularization (TLR). MACE free survival was investigated with Kaplan-Meier curve analysis. Cox regression analysis was used to identify factors associated with MACEs. RESULTS: Baseline clinical characteristics were similar between groups, except for the prevalence of early restenosis (lower) in the DM group. Differences in angiographic and procedural characteristics were not significant between groups. The rates of 2-year MACE (30.9 vs. 26.0%; P = 0.453) and TLR (24.7 vs. 19.7%; P = 0.411) were similar between groups. MACE-free survival and TLR-free survival were also similar between groups (P = 0.441 and P = 0.807). Subgroup analysis suggested a significant difference in the MACE (39.0 vs.15.3%, P < 0.001) and TLR occurrence (30.5 vs.8.2%, P < 0.001) and TLR-free survival (lower in early subgroup, P < 0.001) between early and late occurrence of ISR in the non-DM group of patients but not in the DM group. After adjustment for all significant clinical variables, Cox regression analysis indicated that DM was not associated with MACEs (hazard ratio [HR] 1.531, 95% confidence interval [CI] 0.882-2.658, P =0.130). Non-focal type ISR and early ISR were predictors of MACEs (HR 2.671, 95% CI 1.468-4.858,P = 0.001; HR 4.703, 95% CI 2.725-8.117, P < 0.001, respectively). CONCLUSIONS: Patients with DM have similar 2-year clinical outcomes to patients without DM when repeat 2nd generation DES was used for treatment of DES-ISR. DM is not the predictor of long-term prognosis in patients undergoing repeat 2nd generation DES for DES-ISR.

Neoatherosclerosis and Late Thrombosis After Percutaneous Coronary Intervention: Translational Cardiology and Comparative Medicine from Bench to Bedside.

Neoatherosclerosis is a form of accelerated atherosclerosis that occurs within stented segments of the coronary vessel late or very late after drug-eluting stent (DES) implantation via percutaneous coronary intervention (PCI). This proliferation of neointima with a formation of new atheromatous plaque within stent struts lacking re-endothelialization can provoke thrombotic occlusion and lead to catastrophic acute coronary events. Knowing that coronary artery disease is the leading single cause of mortality worldwide and that there is a constant trend of increase in PCI procedures, it is reasonable to conclude that late thrombotic events and neoatherosclerosis post-PCI remain an important therapeutic challenge. For these reasons, early identification of patients at risk through the means of advanced imaging methods or preventive solutions available through novel technological solutions in DES design that target pro-inflammatory pathways and enable optimized arterial healing are central strategies in prevention and treatment of in-stent neoatherosclerosis and thrombosis. Due to this, pre-clinical studies performed on animal models are crucial building blocks that enable the objective and scientific assessment of innovative technological and therapeutic solutions before they are introduced to early stages of human clinical trials. A comparative medicine approach allows designing and executing experiments in animal models with a high degree of similarity with human coronary anatomy possibly promising the translation of encouraging findings to human clinical studies. The aim of this review is to provide contemporary insights on the pathophysiology of neoatherosclerosis and in-stent thrombosis and emergence of novel biomedical and technological solutions used to counter them.

Influence of Sex on Long-Term Outcomes After Implantation of Bare-Metal Stent: A Multicenter Report From the Coronary Revascularization Demonstrating Outcome Study-Kyoto (CREDO-Kyoto) Registry Cohort-1.

BACKGROUND: Female sex was reported to be associated with lower risk for midterm restenosis and repeat revascularization after bare-metal stent implantation. However, the influence of sex on very long-term outcomes after bare-metal stent implantation has not been yet reported. METHODS AND RESULTS: Among the 9877 patients in the multicenter Coronary Revascularization Demonstrating Outcome study in Kyoto (CREDO-Kyoto) registry cohort-1, bare-metal stent implantation was performed in 5313 patients (men, n=3742 and women, n=1571). Follow-up was completed in 4515 patients (85.0%) at 10 years (duration, 10.3 ± 3.1 [0.0-14.1] years). The cumulative incidence of target-lesion revascularization (TLR) was 27% at 1 year and 34% at 10 years (0.8%/y beyond 1 year). Non-target-lesion revascularization (non-TLR) was the dominant coronary revascularization beyond 1 year (13% at 1 year and 31% at 10 years [2.0%/y beyond 1 year]). Cumulative incidence of stent thrombosis was low (1.2% at 1 year and 1.9% at 10 years). Women were older and had greater prevalence of cardiovascular risk factors than men. The cumulative 10-year incidences of and adjusted risk for TLR were significantly higher in men than in women (36% versus 30%, P<0.001; adjusted hazard ratio, 1.29; 95% confidence interval, 1.15-1.46; P<0.001). The higher risk of men relative to women for TLR was consistent regardless of age (<75 years and ≥ 75 years). Men in comparison with women were also associated with significantly higher adjusted risks for all-cause death, myocardial infarction, stroke, coronary artery bypass grafting, TLR, and non-TLR. CONCLUSIONS: TLR and stent thrombosis continued to occur without attenuation up to 10 years after bare-metal stent implantation. Men in comparison with women were associated with higher adjusted 10-year risks for all-cause death, myocardial infarction, stroke, coronary artery bypass grafting, TLR, and non-TLR.

Drug-Coated Balloon Versus Standard Balloon for Superficial Femoral Artery In-Stent Restenosis: The Randomized Femoral Artery In-Stent Restenosis (FAIR) Trial.

BACKGROUND: Drug-coated balloon angioplasty (DCBA) was shown to be superior to standard balloon angioplasty (POBA) in terms of restenosis prevention for de novo superficial femoral artery disease. For in-stent restenosis, the benefit of DCBA over POBA remains uncertain. METHODS AND RESULTS: One hundred nineteen patients with superficial femoral artery in-stent restenosis and chronic limb ischemia were recruited over 34 months at 5 German clinical sites and prospectively randomized to either DCBA (n=62) or POBA (n=57). Mean lesion length was 82.2±68.4 mm. Thirty-four (28.6%) lesions were totally occluded; 30 (25.2%) were moderately or heavily calcified. Clinical and duplex ultrasound follow-up was conducted at 6 and 12 months. The primary end point of recurrent in-stent restenosis assessed by ultrasound at 6 months was 15.4% (8 of 52) in the DCBA and 44.7% (21 of 47) in the POBA group (P=0.002). Freedom from target lesion revascularization was 96.4% versus 81.0% (P=0.0117) at 6 months and 90.8% versus 52.6% (P<0.0001) at 12 months, respectively. At 12 months, clinical improvement by ≥1 Rutherford category without the need for target lesion revascularization was observed in 35 of 45 DCBA patients (77.8%) and 23 of 44 POBA patients (52.3%; P=0.015). No major amputation was needed. Two patients in the DCBA and 3 patients in the POBA group died. No death was procedure related. CONCLUSIONS: DCBA for superficial femoral artery in-stent restenosis is associated with less recurrent restenosis and a better clinical outcome than POBA without an apparent difference in safety. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01305070.

Local MicroRNA Modulation Using a Novel Anti-miR-21-Eluting Stent Effectively Prevents Experimental In-Stent Restenosis.

OBJECTIVE: Despite advances in stent technology for vascular interventions, in-stent restenosis (ISR) because of myointimal hyperplasia remains a major complication. APPROACH AND RESULTS: We investigated the regulatory role of microRNAs in myointimal hyperplasia/ISR, using a humanized animal model in which balloon-injured human internal mammary arteries with or without stenting were transplanted into Rowett nude rats, followed by microRNA profiling. miR-21 was the only significantly upregulated candidate. In addition, miR-21 expression was increased in human tissue samples from patients with ISR compared with coronary artery disease specimen. We systemically repressed miR-21 via intravenous fluorescein-tagged-locked nucleic acid-anti-miR-21 (anti-21) in our humanized myointimal hyperplasia model. As expected, suppression of vascular miR-21 correlated dose dependently with reduced luminal obliteration. Furthermore, anti-21 did not impede reendothelialization. However, systemic anti-miR-21 had substantial off-target effects, lowering miR-21 expression in liver, heart, lung, and kidney with concomitant increase in serum creatinine levels. We therefore assessed the feasibility of local miR-21 suppression using anti-21-coated stents. Compared with bare-metal stents, anti-21-coated stents effectively reduced ISR, whereas no significant off-target effects could be observed. CONCLUSION: This study demonstrates the efficacy of an anti-miR-coated stent for the reduction of ISR.

Arterial stiffness in patients with coronary artery disease: relation with in-stent restenosis following percutaneous coronary intervention.

BACKGROUND: Coronary artery disease (CAD) is one of the most important issues in modern medicine due to its high mortality and prevalence. An early detection and prevention can reduce morbidity and mortality. Arterial stiffness is a potent and independent predictor of CAD. We aimed to investigate the arterial stiffness in CAD patients undergoing the coronary angiography. Also, we investigated a possible correlation between arterial stiffness and in-stent restenosis (ISR), an important limitation of percutaneous coronary intervention (PCI). METHODS: The study included 160 patients undergoing coronary angiography, treated either with PCI or with CABG. The pulse wave velocity (PWV) and augmentation index (AIx) were measured by the Arteriograph. RESULTS: PWV in the CAD group (12.24 ± 2.78 m/s) was significantly higher compared to the control group (8.27 ± 1.89 m/s). PWV in ISR and left main (LM) stenosis group (14.03 ± 3.15 and 13.89 ± 2.95 m/s) was significantly higher compared to the control and CAD groups. Peripheral and central AIx were significantly higher in CAD group (1.38 ± 30.63 % and 38.35 ± 15.52 %) than in control group (-11.35 ± 26.74 % and 26.91 ± 10.62 %). Patients with LM stenosis have significantly higher values of peripheral and central AIx (23.37 ± 23.77 % and 49.71 ± 12.02 %) than the CAD and ISR group. CONCLUSIONS: The study confirmed a positive correlation between arterial stiffness measures, PWV and AIx, and CAD. Also, this study showed the correlation between PWV and ISR which can help to select more appropriate stent.

Association between cholesterol efflux capacity and coronary restenosis after successful stent implantation.

The measurement of high-density lipoprotein (HDL) functionality could be useful for identifying patients who have an increased risk of coronary restenosis after stent implantation. In the present study, we elucidates whether HDL functionality can predict restenosis. The participants included 48 consecutive patients who had stable angina and were successfully implanted with a drug-eluting stent (DES) or bare-metal stent. Follow-up coronary angiography was performed after 6-8 months of stenting. Cholesterol efflux and the anti-inflammatory capacity of HDL were measured before stenting (at baseline) and at follow-up. The mean age was 64 ± 11 years and the body mass index was 24 ± 3 kg/m(2). While HDL cholesterol (HDL-C) significantly increased from baseline to follow-up, there was no significant association between HDL-C level at baseline and in-stent late loss. Cholesterol efflux capacity was significantly increased from baseline to follow-up. The efflux capacity at baseline was negatively correlated with in-stent late loss, whereas the anti-oxidative activity of HDL at baseline was not associated with in-stent late loss. We analyzed the predictors of in-stent late loss using independent variables (efflux capacity and anti-oxidative capacity at baseline in addition to age, gender, HDL-C and low-density lipoprotein cholesterol at baseline, hypertension, diabetes mellitus, smoking, lesion length and DES implantation, history of myocardial infarction and prior percutaneous coronary intervention) by a multiple regression analysis. The efflux capacity at baseline was only independently associated with in-stent late loss. In conclusion, cholesterol efflux capacity at baseline could predict coronary restenosis in patients with successful stent implantation.

Activation of CXCR7 limits atherosclerosis and improves hyperlipidemia by increasing cholesterol uptake in adipose tissue.

BACKGROUND: The aim of this study was to determine the role of the chemokine receptor CXCR7 in atherosclerosis and vascular remodeling. CXCR7 is the alternative receptor of CXCL12, which regulates stem cell-mediated vascular repair and limits atherosclerosis via its receptor, CXCR4. METHODS AND RESULTS: Wire-induced injury of the carotid artery was performed in mice with a ubiquitous, conditional deletion of CXCR7 and in mice treated with the synthetic CXCR7 ligand CCX771. The effect of CCX771 treatment on atherosclerosis was studied in apolipoprotein E-deficient (Apoe(-/-)) mice fed a high-fat diet for 12 weeks. Lipoprotein fractions were quantified in the plasma of Apoe(-/-) mice by fast protein liquid chromatography. Uptake of DiI-labeled very low-density lipoprotein to adipose tissue was determined by 2-photon microscopy. We show that genetic deficiency of Cxcr7 increased neointima formation and lesional macrophage accumulation in hyperlipidemic mice after vascular injury. This was related to increased serum cholesterol levels and subsequent hyperlipidemia-induced monocytosis. Conversely, administration of the CXCR7 ligand CCX771 to Apoe(-/-) mice inhibited lesion formation and ameliorated hyperlipidemia after vascular injury and during atherosclerosis. Treatment with CCX771 reduced circulating very low-density lipoprotein levels but not low-density lipoprotein or high-density lipoprotein levels and increased uptake of very low-density lipoprotein into Cxcr7-expressing white adipose tissue. This effect of CCX771 was associated with an enhanced lipase activity and reduced expression of Angptl4 in adipose tissue. CONCLUSIONS: CXCR7 regulates blood cholesterol by promoting its uptake in adipose tissue. This unexpected cholesterol-lowering effect of CXCR7 is beneficial for atherosclerotic vascular diseases, presumably via amelioration of hyperlipidemia-induced monocytosis, and can be augmented with a synthetic CXCR7 ligand.

Pathology of second-generation everolimus-eluting stents versus first-generation sirolimus- and paclitaxel-eluting stents in humans.

BACKGROUND: Clinical trials have demonstrated that the second-generation cobalt-chromium everolimus-eluting stent (CoCr-EES) is superior to the first-generation paclitaxel-eluting stent (PES) and is noninferior or superior to the sirolimus-eluting stent (SES) in terms of safety and efficacy. It remains unclear whether vascular responses to CoCr-EES are different from those to SES and PES because the pathology of CoCr-EES has not been described in humans. METHODS AND RESULTS: A total of 204 lesions (SES=73; PES=85; CoCr-EES=46) from 149 autopsy cases with duration of implantation >30 days and ≤3 years were pathologically analyzed, and comparison of vascular responses was corrected for duration of implantation. The observed frequency of late and very late stent thrombosis was less in CoCr-EES (4%) versus SES (21%; P=0.029) and PES (26%; P=0.008). Neointimal thickness was comparable among the groups, whereas the percentage of uncovered struts was strikingly lower in CoCr-EES (median=2.6%) versus SES (18.0%; P<0.0005) and PES (18.7%; P<0.0005). CoCr-EES showed a lower inflammation score (with no hypersensitivity) and less fibrin deposition versus SES and PES. The observed frequency of neoatherosclerosis, however, did not differ significantly among the groups (CoCr-EES=29%; SES=35%; PES=19%). CoCr-EES had the least frequency of stent fracture (CoCr-EES=13%; SES=40%; PES=19%; P=0.007 for CoCr-EES versus SES), whereas fracture-related restenosis or thrombosis was comparable among the groups (CoCr-EES=6.5%; SES=5.5%; PES=1.2%). CONCLUSIONS: CoCr-EES demonstrated greater strut coverage with less inflammation, less fibrin deposition, and less late and very late stent thrombosis compared with SES and PES in human autopsy analysis. Nevertheless, the observed frequencies of neoatherosclerosis and fracture-related adverse pathological events were comparable in these devices, indicating that careful long-term follow-up remains important even after CoCr-EES placement.

Comparison of scanning electron microscopy and optical coherence tomography for imaging of coronary bifurcation stents.

BACKGROUND: Optical coherence tomography (OCT) is a new intracoronary imaging modality that has excellent resolution and image quality and has been used to image neointimal coverage after stent implantation. OCT has been compared to histologic, intravascular ultrasound, and scanning electron microscopy (SEM) studies. However, OCT has not been compared with SEM for imaging stent coverage over side branches. OBJECTIVE: The aim of this study was to compare OCT with SEM in imaging neointimal coverage over stent struts bridging coronary side-branch ostia. METHODS: Using a balloon-overstretch in-stent restenosis model, we deployed 38 everolimus-eluting stents across coronary bifurcations in nine pigs. We performed OCT immediately after stenting and 4 weeks later; SEM was performed after euthanizing the pigs. OCT images of each stent were compared to the corresponding SEM image. RESULTS: We analyzed OCT frames (n=111) for strut-level neointimal coverage and compared them to corresponding SEM images. The concordance correlation coefficient was 0.809 (95%CI; 0.734-0.864) and 0.951 (95%CI; 0.930-0.966) for covered and uncovered struts, respectively. CONCLUSIONS: In a non-atherosclerotic pig model, we showed strong agreement between OCT and SEM in imaging coverage of stent struts bridging side-branch ostia.