Defining coronary restenosis. Newer clinical and angiographic paradigms

Efficacy of paclitaxel-coated versus uncoated balloon angioplasty for revascularization of coronary in-stent restenosis: a meta-analysis and metaregression

BACKGROUND

Treatment of in-stent restenosis (ISR) accounts for 10% of percutaneous coronary interventions in the USA. Paclitaxel-coated balloons (PCBs) are an alternative to uncoated balloons (UCBs) for ISR.

METHODS

We systematically searched PubMed, Scopus, and Cochrane Central for studies comparing PCB with UCB in treating ISR. Outcomes included late lumen loss, binary restenosis, target lesion revascularization (TLR), and major adverse cardiovascular events (MACE).

RESULTS

Eight trials including 1410 patients [PCB in 865 (61%), follow-up 6 months to 10 years) were identified. Angiographic outcomes of late lumen loss [mean difference: -0.50 mm; 95% confidence interval (CI): -0.66 to -0.33; P < 0.01] and binary restenosis [relative risk (RR): 0.22; 95% CI: 0.13-0.40; P < 0.01] at 6-8 months were lower with PCB. TLR at 6 months (RR: 0.16; 95% CI: 0.06-0.40; P < 0.001) and 1 year (RR: 0.45; 95% CI: 0.31-0.66; P < 0.001), MACE at 6 months (RR: 0.25; 95% CI: 0.16-0.38; P < 0.001), MACE at 3-5 years (RR: 0.54; 95% CI: 0.37-0.80; P = 0.002), and TLR at 3-5 years (RR: 0.51; 95% CI: 0.29-0.90; P = 0.021) were lower with PCB. Meta-regression revealed that ISR lesions in the left anterior descending artery were associated with lower rates of binary restenosis while the opposite was observed for left circumflex lesions.

CONCLUSION

Revascularization of coronary ISR with PCB is associated with reduced late lumen loss, binary restenosis, TLR, CCE, and MACE. PCB may be a preferred strategy for coronary ISR.

Pre-Percutaneous Coronary Intervention C-Reactive Protein Levels and In-Stent Restenosis: A Systematic Review and Meta-Analysis

Introduction

C-reactive protein (CRP) is an inflammatory biomarker, implicated in the pathogenesis of atherosclerotic lesion formation, plaque rupture, and coronary thrombosis. The relationship between preprocedural CRP levels and subsequent development of in-stent restenosis (ISR) after percutaneous coronary intervention (PCI) however remains uncertain. Against this background, we performed a systematic review and meta-analysis, investigating the association between baseline CRP levels and the incidence of ISR after PCI.

Methods

Relevant published studies were identified following a PubMed, EMBASE, MEDLINE, Scopus and Web of Knowledge databases search until April 30, 2024. To be included, studies had to be original research with: (i) angiographically determined ISR group, (ii) angiographically or clinically determined no-ISR group, and (iii) CRP levels measured before the index PCI procedure for both groups. The mean difference in baseline CRP levels and associated 95% confidence interval (CI) between the ISR and no-ISR groups was ascertained for each included study. The pooled standard mean difference (SMD) and its 95% CI was derived after pooling study-level results using a random effects model, employing a Z-test. Begg's funnel plots and Egger's test were used for publication bias assessment.

Results

Out of a total of 1018 unique results, 19 studies, with a total sample size of 4744 patients (1154 restenosis cases/3590 controls), were included for quantitative synthesis. ISR group had higher baseline CRP levels (SMD = 0.41, 95% CI = 0.16, 0.66 mg/L, p = 0.001) in comparison to the no-ISR group. No evidence of publication bias was detected either visually by Begg's funnel plots or by Egger's test (p = 0.08). Our leave-one-out sensitivity analysis further attested our obtained associations.

Conclusions

The present systematic review and meta-analysis suggests a significant association of elevated pre-PCI CRP with subsequent angiographically confirmed ISR. These results warrant further validation in dedicated large cohorts, ideally in a prospective setting.

Diagnostic performance of CCTA and CTP imaging for clinically suspected in-stent restenosis: A meta-analysis

AIMS

The objective of this study is to conduct a meta-analysis to assess the diagnostic performance of Coronary Computed Tomography Angiography (CCTA) and a hybrid approach that incorporates Computed Tomography Perfusion (CTP) in addition to CCTA (CCTA ​+ ​CTP) for the detection of in-stent restenosis (ISR), as defined by angiography.

METHODS

A comprehensive search of articles identified 18,513 studies. After removing duplicates, title/abstract screening, and full-text review, 17 CCTA and 3 CCTA ​+ ​CTP studies were included. Only studies using ≥64-slices multidetector computed tomography (CT) were considered eligible.

RESULTS

The per-patient ISR prevalence was 43 ​%, with 92 ​% of stents fully interpretable with CCTA. Meta-analysis exhibited a per-stent CCTA (n ​= ​2674) sensitivity of 90 ​% (95 ​% CI; 84-94 ​%), specificity of 89 ​% (95 ​% CI; 86-92 ​%), positive likelihood ratio of 7.17 (95 ​% CI; 5.24-9.61), negative likelihood ratio of 0.17 (95 ​% CI; 0.10-0.25), and diagnostic odds ratio of 45.7 (95 ​% CI; 22.71-82.43). Additional sensitivity analyses revealed no influence of stent diameter or strut thickness on the diagnostic yield of CCTA. The per-stent diagnostic performance of CCTA ​+ ​CTP (n ​= ​752) did not show differences compared to CCTA.

CONCLUSIONS

With currently utilized scanners, CCTA and CCTA ​+ ​CTP demonstrated high diagnostic performance for in-stent restenosis evaluation. Consequently, a history of previous stent implantation should not be an argument to preclude using these methods in clinically suspected patients.

Intravascular imaging and functional assessment for coronary in-stent restenosis: Current status and future directions

Despite significant advancements in drug-eluting stent technology, in-stent restenosis (ISR) still occurs in approximately 10 % of patients undergoing percutaneous coronary intervention, remaining a significant global health concern. The mechanisms underlying ISR are complex and multifactorial, yet recent innovations in intravascular imaging and functional assessment have substantially advanced our understanding, enabling more targeted and personalized therapies. This review synthesizes the latest insights into ISR, emphasizing the pivotal roles of advanced imaging modalities, such as optical coherence tomography (OCT) and intravascular ultrasound, and functional assessments like quantitative flow ratio and optical flow ratio in guiding ISR management. Additionally, we explore the clinical implications of in-stent neoatherosclerosis and calcified nodules as key pathological mechanisms influencing restenosis progression and patient outcomes. The review also highlights the significance of OCT-based ISR classifications in refining treatment approaches. By integrating these diagnostic and therapeutic advances, this work provides clinicians and researchers with an updated foundation and actionable insights for optimizing ISR management through tailored, imaging-guided strategies.

Peculiarities of in-Stent Thrombosis and Restenosis in Coronary Arteries Post-COVID-19: A Systematic Review of Clinical Cases and Case Series

Background

One of the most serious complications of coronary artery stenting is restenosis and in-stent thrombosis; their prevalence can reach 20-25%. Stent thrombosis can be acute (up to 24 hours), subacute (24 hours to 30 days), late (30 days to 1 year), and very late (> 1 year after previous stenting). In the patients with COVID-19 in intensive care units, the proportion of those with elevated troponin levels reached 25%.

Objective

Evaluation of the association between COVID-19 and the development of in-stent thrombosis and restenosis of the coronary arteries based on the analysis of clinical cases and case series.

Materials and Methods

We searched the PubMed and Scopus databases for relevant case reports and case series of stent restenosis and in-stent thrombosis associated with coronavirus infection (CVI) published between 2020 and the present. Thirty-eight full-text publications were screened and manually checked for analysis. We found 10 publications describing cases of thrombosis and restenosis of stents associated with coronavirus infection, of which only 2 were case series. In total, we analyzed 22 cases.

Results

In the structure of in-stent restenosis and thrombosis, 59.1% were very late, 9.1% were late; 18.2% were considered subacute events, and 13.6% were acute events. All cases were angiographically confirmed. The main location of restenosis or thrombosis was the left coronary artery (LAD) (51.1%), thrombosis of the right coronary artery (RCA) occurred in 27.3%, and location in circumflex artery was in 22.7%. All patients had COVID-19 confirmed by a PCR test or the presence of immunoglobulins G and M. In fourteen patients (54.5%), an X-ray examination showed the presence of bilateral polysegmental infiltration.

Conclusion

Analysis of publications demonstrates the association between restenosis and in-stent thrombosis in patients with coronary arteries disease (CAD) and coronavirus infection.

Comparison of Outcome After Percutaneous Coronary Intervention for De Novo and In-Stent Restenosis Indications

In-stent restenosis (ISR) still occurs after percutaneous coronary intervention (PCI). Few studies have compared the outcomes of PCI for de novo stenosis with those of PCI for ISR, and the results are conflicting. The present study aimed to conduct this comparison. Using patient-level data from the randomized all-comer SORT OUT studies III to X, we included all patients with previous PCI and either an ISR or a de novo lesion as the study target lesion. Outcomes of interest were major adverse cardiac events (MACE) and target lesion revascularization (TLR) after 5 years. Of the 2,928 patients with a previous PCI included in the SORT OUT studies, 491 (17%) were treated for ISR and 2,437 (83%) for a de novo stenosis. Baseline characteristics did not differ significantly. At 5 years, MACE occurred in 148 patients (32%) in the ISR group and 654 patients (28%) in the de novo stenosis group (crude and adjusted hazard ratio 1.16 [95% confidence interval (CI) 0.97 to 1.38] and 1.16 [95% CI 0.97 to 1.38]). The risk of TLR was higher in the ISR group compared with the de novo stenosis group (crude and adjusted hazard ratio 1.64 [95% CI 1.24 to 2.17] and 1.71 [95% CI 1.27 to 2.30]). In conclusion, the risk of MACE was similar between PCI for ISR and PCI for de novo lesions after 5 years. However, the risk of TLR was higher in the ISR group compared with the de novo stenosis group.

Meta-Analysis Comparing Drug-Coated Balloon Versus Plain Old Balloon Angioplasty for In-Stent Restenosis of Coronary Arteries

Despite the advent of newer stents, in-stent restenosis has been a persistent and formidable challenge. Trials have demonstrated the superiority of drug-coated balloons over plain old balloon angioplasty. A recent AGENT IDE PRESTO (Prevention of REStenosis with Tranilast and its Outcomes) trial highlighted the need for a more comprehensive understanding; therefore, we conducted a meta-analysis to elucidate their respective clinical outcomes. A literature search was conducted by 2 investigators (SS and MH) using MEDLINE (EMBASE and PubMed) using a systematic search strategy by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) until November 1, 2023. CRAN-R software was used for statistical analysis. The quality assessment was performed using the Cochrane Risk of Bias tool (Supplementary Table 5). We included 6 studies with a total of 1,171 patients. Our analysis showed decreased odds of multiple outcomes with statistically significant results, including target vessel revascularization (odds ratio [OR] 0.33, confidence interval [CI] 0.19 to 0.57), target vessel failure (OR 0.30, CI 0.09 to 0.99), target lesion revascularization (OR 0.22, CI 0.10 to 0.46), restenosis (OR 0.1343, CI 0.06 to 0.27), and major adverse cardiac events (OR 0.2 CI 0.12 to 0.37). Although myocardial infraction and all-cause mortality showed decreased odds with all-cause mortality at 0.8 (95% CI 0.363 to 2.09), and myocardial infarction at 0.6 (95% CI 0.0349 to 1.07), the reductions did not reach statistical significance. Our analysis by scrutinizing 6 randomized controlled trials favored drug-coated balloons over plain old balloon angioplasty. However, extensive research for deeper understanding cannot be overemphasized.

The Effect of Angiotensin Receptor Blockers on In-Stent Restenosis After Stent Implantation: A Meta-Analysis

AIM

Angiotensin receptor blockers (ARBs) have been shown to inhibit restenosis in vitro and in vivo, but the evidence found in humans is inconsistent. This study aimed to evaluate the effectiveness of ARBs in preventing in-stent restenosis after percutaneous coronary intervention (PCI).

METHOD

Databases including the Cochrane Library, MEDLINE, Web of Science, EMBASE, and CNKI were searched to collect randomised controlled trials on ARBs inhibiting restenosis that were published before October 2022. A total of 1,056 patients enrolled in eight trials were included in the study.

RESULTS

The ARBs group showed lower target lesion revascularisation than the control group (RR 0.54; 95% CI 0.34-0.86; p=0.01), but the restenosis incidence between these two groups was not statistically significant (RR 0.85; 95% CI 0.65-1.11; p>0.05).

CONCLUSION

This study found that ARBs might have a potential effect on reducing target lesion revascularisation after PCI in coronary heart disease patients but has no impact on angiographic restenosis.

Diagnostic Performance of Machine Learning-Derived Radiomics Signature of Pericoronary Adipose Tissue in Coronary Computed Tomography Angiography for Coronary Artery In-Stent Restenosis

RATIONALE AND OBJECTIVES

Coronary inflammation can alter the perivascular fat phenotype. Hence, we aimed to assess the diagnostic performance of radiomics features of pericoronary adipose tissue (PCAT) in coronary computed tomography angiography (CCTA) for in-stent restenosis (ISR) after percutaneous coronary intervention.

MATERIALS AND METHODS

In this study, 165 patients with 214 eligible vessels were included, and ISR was found in 79 vessels. After evaluating clinical and stent characteristics, peri-stent fat attenuation index, and PCAT volume, 1688 radiomics features were extracted from each peri-stent PCAT segmentation. The eligible vessels were randomly categorized into training and validation groups in a ratio of 7:3. After performing feature selection using Pearson's correlation, F test, and least absolute shrinkage and selection operator analysis, radiomics models and integrated models that combined selected clinical features and Radscore were established using five different machine learning algorithms (logistic regression, support vector machine, random forest, stochastic gradient descent, and XGBoost). Subgroup analysis was performed using the same method for patients with stent diameters of ≤ 3 mm.

RESULTS

Nine significant radiomics features were selected, and the areas under the curves (AUCs) for the radiomics model and the integrated model were 0.69 and 0.79, respectively, for the validation group. The AUCs of the subgroup radiomics model based on 15 selected radiomics features and the subgroup integrated model were 0.82 and 0.85, respectively, for the validation group, which showed better diagnostic performance.

CONCLUSION

CCTA-based radiomics signature of PCAT has the potential to identify coronary artery ISR without additional costs or radiation exposure.

Prevalence, Management and Outcomes of Percutaneous Coronary Intervention for Coronary In-Stent Restenosis: Insights From the France PCI Registry

BACKGROUND

Despite the evolution of stent technology, there is a non-negligible risk of in-stent restenosis (ISR) after Percutaneous coronary intervention (PCI). Large-scale registry data on the prevalence and clinical management of ISR is lacking.

METHODS

The aim was to describe the epidemiology and management of patients with ≥1 ISR lesions treated with PCI (ISR PCI). Data on characteristics, management and clinical outcomes were analyzed for patients undergoing ISR PCI in the France-PCI all-comers registry.

RESULTS

Between January 2014 and December 2018, 31,892 lesions were treated in 22,592 patients, 7.3 % of whom underwent ISR PCI. Patients undergoing ISR PCI were older (68.5 vs 67.8; p < 0.001), and more likely to have diabetes (32.7 % vs 25.4 %, p < 0.001), chronic coronary syndrome or multivessel disease. ISR PCI concerned drug eluting stents (DES) ISR in 48.8 % of cases. Patients with ISR lesions were more frequently treated with DES than drug eluting balloon or balloon angioplasty (74.2 %, 11.6 % and 12.9 %, respectively). Intravascular imaging was rarely used. At 1 year, patients with ISR had higher target lesion revascularization rates (4.3 % vs. 1.6 %; HR 2.24 [1.64-3.06]; p < 0.001).

CONCLUSIONS

In a large all-comers registry, ISR PCI was not infrequent and associated with worse prognosis than non-ISR PCI. Further studies and technical improvements are warranted to improve the outcomes of ISR PCI.

Coronary Drug-Coated Balloons for De Novo and In-Stent Restenosis Indications

Drug-coated balloons are approved outside the United States, not only for the treatment of peripheral arteries but also for coronary arteries. This review describes the technological basics, the scenarios of clinical application, and the current available data from clinical trials for the different coronary indications.

Nanoparticle coatings for controlled release of quercetin from an angioplasty balloon

Peripheral artery disease (PAD) is a systemic vascular disease of the legs that results in a blockage of blood flow from the heart to the lower extremities. Now one of the most common causes of mortality in the U.S., the first line of therapy for PAD is to mechanically open the blockages using balloon angioplasty. Coating the balloons with antiproliferative agents can potentially reduce vessel re-narrowing, or restenosis after surgical intervention, but current drug-coated balloons releasing chemotherapy agents like paclitaxel have in some cases shown increased mortality long-term. Our aim was to design a novel drug-coated balloon using a polymeric nanodelivery system for a sustained release of polyphenols that reduce restenosis but with reduced toxicity compared to chemotherapy agents. Poly (lactic-co-glycolic acid) (PLGA) nanoparticles with entrapped quercetin, a dimethoxy quercetin (rhamnazin), as well as quercetin covalently attached to PLGA, were developed. Balloon catheters were coated with polymeric nanoparticles using an ultrasonic method, and nanoparticle characteristics, drug loading, coating uniformity and drug release were determined. The adhesion of nanoparticles to vascular smooth muscle cells and the antiproliferative effect of nano-delivered polyphenols were also assessed. Of the nanoparticle systems tested, those with covalently attached quercetin provided the most sustained release over a 6-day period. Although these particles adhered to cells to a smaller extent compared to other nanoparticle formulations, their attachment was resistant to washing. These particles also exhibited the greatest anti-proliferative effect. In addition, their attachment was not altered when the cells were grown in calcifying conditions, and in PAD tissue calcification is typically a condition that impedes drug delivery. Moreover, the ultrasonic coating method generated a uniform balloon coating. The polymeric nanoparticle system with covalently attached quercetin developed herein is thus proposed as a promising platform to reduce restenosis post-angioplasty.

Intravascular imaging in coronary stent restenosis: Prevention, characterization, and management

Despite the introduction of drug-eluting stents to combat the neointimal hyperplasia that occurred after BMS implantation, in-stent restenosis is still encountered in a significant number of patients, particularly as increasingly complex lesions are tackled by percutaneous coronary intervention. Many biological and mechanical factors interplay to produce restenosis, some of which are avoidable. Intravascular imaging provided unique insights into various forms of stent-related mechanical issues that contribute to this phenomenon. From a practical perspective, intravascular imaging can therefore help to optimize the stenting procedure to avert these issues. Moreover, once the problem of restenosis eventuates, imaging can guide the management by tackling the underlying identified mechanism. Finally, it can be used to evaluate the re-intervention results. Nevertheless, with the emergence of different treatment options, more evidence is needed to define patient/lesion-specific characteristics that may help to tailor treatment selection in a way that improves clinical outcomes.

Management of in-stent restenosis

In-stent restenosis (ISR) remains the most common cause of stent failure after percutaneous coronary intervention (PCI). Recent data suggest that ISR-PCI accounts for 5-10% of all PCI procedures performed in current clinical practice. This State-of-the-Art review will primarily focus on the management of ISR but will begin by briefly discussing diagnosis and classification. We then move on to detail the evidence base underpinning the various therapeutic strategies for ISR before finishing with a proposed ISR management algorithm based on current scientific data.

Random forest vs. logistic regression: Predicting angiographic in-stent restenosis after second-generation drug-eluting stent implantation

As the rate of percutaneous coronary intervention increases, in-stent restenosis (ISR) has become a burden. Random forest (RF) could be superior to logistic regression (LR) for predicting ISR due to its robustness. We developed an RF model and compared its performance with the LR one for predicting ISR. We retrospectively included 1501 patients (age: 64.0 ± 10.3; male: 76.7%; ISR events: 279) who underwent coronary angiography at 9 to 18 months after implantation of 2nd generation drug-eluting stents. The data were randomly split into a pair of train and test datasets for model development and validation with 50 repeats. The predictive performance was assessed by the area under the curve (AUC) of the receiver operating characteristic (ROC). The RF models predicted ISR with larger AUC-ROCs of 0.829 ± 0.025 compared to 0.784 ± 0.027 of the LR models. The difference was statistically significant in 29 of the 50 repeats. The RF and LR models had similar sensitivity using the same cutoff threshold, but the specificity was significantly higher in the RF models, reducing 25% of the false positives. By removing the high leverage outliers, the LR models had comparable AUC-ROC to the RF models. Compared to the LR, the RF was more robust and significantly improved the performance for predicting ISR. It could cost-effectively identify patients with high ISR risk and help the clinical decision of coronary stenting.

The Impact of Subclinical Hyperthyroidism on Cardiovascular Prognosis in Patients Undergoing Percutaneous Coronary Intervention

CONTEXT

Limited studies have focused on the impact of subclinical hyperthyroidism (SHyper) on poor prognosis in patients with known coronary artery disease (CAD).

OBJECTIVE

We implemented the present study to explore the association between SHyper and adverse cardiovascular events in CAD patients who underwent drug-eluting stent implantation.

METHODS

We consecutively recruited 8283 CAD patients undergoing percutaneous coronary intervention (PCI). All subjects were divided into 2 groups according to their thyroid function: group 1 (euthyroidism group, n = 7942) and group 2 (SHyper group, n = 341). After 1:4 propensity score (PS) matching, 1603 patients (332 SHyper group and 1271 euthyroidism group) were selected. The primary endpoint was major adverse cardiovascular events (MACEs), a composite of cardiac mortality, nonfatal myocardial infarction (MI), and target vessel revascularization (TVR).

RESULTS

Kaplan-Meier (K-M) survival analyses suggested that there was no significant difference in the primary endpoint and secondary endpoints (MACE: 11.4% vs 8.8%, log-rank P = .124; cardiac death: 1.2% vs 0.9%, log-rank P = .540; nonfatal MI: 5.7% vs 4%, log-rank P = .177; and TVR: 6% vs 4.7%, log-rank P = .303) in the PS-matched population. Cox regression analysis indicated that SHyper was not an independent risk factor for MACEs (HR 1.33, 95% CI 0.92-1.92, P = .127).

CONCLUSION

SHyper is not independently associated with adverse cardiovascular events in CAD patients undergoing PCI. More studies should be implemented in the future to assess the long-term predictive value of SHyper with thyrotropin levels <0.1 mIU/L for CAD patients undergoing PCI.

Non-Fasting Hypertriglyceridemia as an Independent Risk Factor for Coronary In-Stent Restenosis after Primary Bare Metal Stent Implantation in Patients with Coronary Artery Disease

After a percutaneous coronary intervention (PCI) in patients with coronary artery disease (CAD), in-stent neoatherosclerosis may pose a risk of in-stent restenosis (ISR). To clarify whether non-fasting hypertriglyceridemia contributes to ISR, we examined the relationship between non-fasting hypertriglyceridemia (i.e., triglyceride (TG) level ≥ 200 mg/dL) and ISR after stenting with a bare metal stent (BMS) post-primary PCI in patients with CAD by means of a single-site retrospective analysis. A total of 1,039 patients with CAD were enrolled, and 86 patients (112 lesions) were evaluated for BMS-ISR 3-6 months post-primary PCI. The percentage of patients with non-fasting hypertriglyceridemia was significantly higher in the ISR (+) group than in the ISR (-) group (P < 0.009). The follow-up period and number of patients in the ISR (+) group were significantly smaller than those in the ISR (-) group (P < 0.001). There were no significant between-group differences in the other baseline patient characteristics before the primary PCI or at the time of the follow-up coronary angiography. However, at the follow-up period, the ISR (+) group had significantly lower diastolic blood pressure and high-density lipoprotein cholesterol levels (P = 0.015) and significantly higher TG levels (P = 0.012) than the ISR (-) group. A multiple logistic regression analysis demonstrated that non-fasting hypertriglyceridemia and a follow-up period of ≥ 6 months were independent risk factors for ISR after primary PCI in patients with BMS implantation for stenotic CAD (P = 0.006), with an adjusted odds ratio of 8.232 (1.201-56.410) and 0.006 (95% confidence interval < 0.001-0.045), respectively. Non-fasting hypertriglyceridemia may be an additional independent risk factor for BMS-ISR after primary PCI in patients with CAD.

Coronary In-Stent Restenosis: Predictors and Treatment

BACKGROUND

Despite the use of modern drug-eluting stents (DES), in-stent restenosis (ISR) may still occur in as many as 2-10% of percutaneous coronary interventions (PCI) in certain lesion/patient subsets. ISR causes increased morbidity after stent implantation; acute myocardial infarction is a frequent correlate to a clinical ISR, arising in 5-10% of cases. Compared to de novo stenosis, patients with ISR also present more frequently with symptoms of unstable angina pectoris (45% versus 61%). In this article, we discuss the risk factors for ISR and the corresponding diagnostic measures and effective treatment strategies.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, with special attention to current international guidelines and specialist society recommendations.

RESULTS

The type of implanted stent, the presence of diabetes mellitus, previous bypass surgery, and small vessel caliber are predictors for ISR. In their guidelines, the European specialist societies (ESC/EACTS) recommend repeated PCI with DES implantation or drug-coated balloon (DCB) angioplasty as the methods of choice for the treatment of ISR. This approach is supported by evidence from meta-analyses. The RIBS-IV trial showed that revascularization treatment of the target lesion is needed less often after everolimus-eluting stent (EES) implantation than after DCB dilatation (11 [7.1%] versus 24 [15.6%]; p = 0.015; hazard ratio: 0.43; 95% confidence interval: [0.21; 0.87]).

CONCLUSION

Because the pathogenesis of ISR is multifactorial, differentiated risk stratification is necessary. The identification of patient-, stent-, and lesion-related predictors is particularly important, as the most effective way to combat ISR is to prevent it.

Mechano-chemo-biological Computational Models for Arteries in Health, Disease and Healing: From Tissue Remodelling to Drug-eluting Devices

This review aims to highlight urgent priorities for the computational biomechanics community in the framework of mechano-chemo-biological models. Recent approaches, promising directions and open challenges on the computational modelling of arterial tissues in health and disease are introduced and investigated, together with in silico approaches for the analysis of drug-eluting stents that promote pharmacological-induced healing. The paper addresses a number of chemo-biological phenomena that are generally neglected in biomechanical engineering models but are most likely instrumental for the onset and the progression of arterial diseases. An interdisciplinary effort is thus encouraged for providing the tools for an effective in silico insight into medical problems. An integrated mechano-chemo-biological perspective is believed to be a fundamental missing piece for crossing the bridge between computational engineering and life sciences, and for bringing computational biomechanics into medical research and clinical practice.

Periodontitis Is Associated With Risk of Conventional Stent Restenosis: Pilot Case-Control Study

Objectives: Percutaneous coronary angioplasty with stent implantation has been established as the main form of treatment of atherosclerosis. However, 16 to 44% of patients may evolve with stent restenosis. Periodontitis is an inflammatory condition associated with bacterial infection, that may lead to periodontal tissue destruction and tooth loss. This study aimed to evaluate the association between stent restenosis and periodontitis.

Materials and Methods: Coronary angiography exams presenting stent imaging with and without restenosis were analyzed. Patients meeting the inclusion and exclusion criteria were selected and allocated in 2 groups: case (restenosis) and control (without restenosis). We evaluated if systemic and periodontal variables were predictors of restenosis (primary outcome) using a multivariable stepwise logistic regression. Additionally, we compared clinical and periodontal conditions between the control and case groups (secondary outcomes) using Chi-square test and ANOVA test.

Results: Data from 49 patients (case n = 15; control n = 34) were analyzed. The results showed that stages III and IV periodontitis and lack of physical activity were significant predictors of stent restenosis (OR 5.82 and 5.98, respectively). Comparisons regarding the diagnosis of periodontal conditions between control and case groups did not present significant differences in the incidence of periodontitis and alveolar bone loss.

Conclusion: Stages III and IV periodontitis increased the incidence of stent restenosis. These findings suggest that advanced stages of periodontal disease might lead to the occurrence of negative outcomes after coronary angioplasty with stent placement.

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.

Risk prediction of in-stent restenosis among patients with coronary drug-eluting stents: current clinical approaches and challenges

Introduction: In-stent restenosis (ISR) has been one of the biggest limitations to the success of percutaneous coronary intervention for the treatment of coronary artery disease (CAD). The introduction of drug-eluting stent (DES) was a revolution in the treatment of CAD because these devices drastically reduced ISR to very low levels (<5%). Subsequently, newer generation DES treatments have overcome the drawbacks of first-generation DES, i.e. delayed endothelialization, and late stent thrombosis. However, the issue of late ISR, including neoatherosclerosis after DES implantation especially in high-risk patients and complex lesions, still exists as a challenge to be overcome.Areas covered: We discuss the mechanisms of ISR development including neoatherosclerosis, past and current clinical status of ISR, and methods to predict and overcome this issue from pathological and clinical points of view.Expert opinion: The initial drawbacks of first-generation DES, such as delayed endothelial healing and subsequent risk of late stent thrombosis, have been improved upon by the current generation DES. To achieve better long-term clinical outcomes, further titration of drug-release and polymer degradation profile, strut thickness as well as material innovation are needed.

The Impact of the Triglyceride-Glucose Index on Poor Prognosis in NonDiabetic Patients Undergoing Percutaneous Coronary Intervention

BACKGROUND

The triglyceride-glucose index (TyG index) is a valuable marker for predicting adverse cardiovascular events in diabetic patients. However, for nondiabetic patients, whether the TyG index is independently related to poor prognosis remains unclear. This cohort study assessed the association of the TyG index with future cardiovascular risk in nondiabetic subjects who received percutaneous coronary intervention (PCI).

METHODS

We consecutively enrolled 5,489 nondiabetic patients who underwent PCI. All experimental subjects were divided into three groups based on their TyG index, which was determined by the equation ln (fasting triglyceride (mg/dl) × fasting blood glucose (mg/dl)/2). The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE), including all-cause death, nonfatal myocardial infarction (MI), nonfatal stroke, and target vessel revascularization (TVR).

RESULTS

A total of 386 MACCE were documented during a median 29-month follow-up. The Kaplan-Meier survival results indicated that among the three groups, there was no obvious difference in any endpoints. Further Cox regression analyses suggested that the TyG index was not independently related to adverse cardiovascular outcomes for nondiabetic patients who underwent PCI (HR: 0.77, 95% CI 0.56-1.16, P = 0.210 for MACCE). Subgroup analysis suggested that the TyG index was independently relevant to MACCE for patients with low-density lipoprotein cholesterol (LDL-C) lower than 1.8 mmol/L.

CONCLUSION

The TyG index is not an effective predictive factor for adverse cardiovascular prognosis in nondiabetic patients who underwent PCI. However, in subjects with LDL-C lower than 1.8mmol/L, it may predict future cardiovascular risk.

MiR-93-5p is a novel predictor of coronary in-stent restenosis

Aims

MicroRNAs (miRNAs), small non-coding RNAs, have been implicated as regulators of multiple phases of atherothrombosis, and some reports have suggested altered levels in coronary artery in-stent restenosis (ISR). We recently demonstrated that miR-93-5 p was able to discriminate between patients with stable coronary artery disease (CAD) and those with no CAD, after adjusting for traditional risk factors (RFs). Thus, we wanted to determine if circulating miRNAs could predict coronary ISR.

Objective

To determine if circulating miRNAs have diagnostic capability for determining ISR in a cohort of matched patients with and without ISR.

Approach and results

To determine if miRNA plasma levels are elevated in coronary ISR, we conducted a study comprising 78 patients (39 with no ISR and 39 with ISR) and measured plasma miRNAs in each. We then determined the predictive ability of differential miRNAs, adjusting for Framingham Heart Study (FHS) RFs, and stent length and diameter, to discriminate between ISR and no ISR. After correction for multiple testing, two miRNAs—miR425-5p and miR-93-5 p—were differential between patients with ISR and patients without ISR. Only miR-93-5 p remained a strong independent predictor of ISR after correction for FHS RFs (OR 6.30, p=0.008) and FHS RFs plus stent length and diameter (OR 4.80, p=0.02) and improved discriminatory power for ISR over FHS RFs alone in receiver operator characteristic curve analysis.

Conclusion

This novel finding that miR-93-5 p independently predicts ISR extends our recent observation that miR-93-5 p predicted CAD after adjustment for traditional CAD RFs. These data suggest further potential diagnostic utility.

Effectiveness and Safety of Compound Chinese Medicine plus Routine Western Medicine in In-Stent Restenosis: A Meta-Analysis and Systematic Review

Objective

To examine the effects and safety of oral compound Chinese medicine (CCM) plus routine western medicine (RWM) in in-stent restenosis (ISR).

Methods

Various electronic databases (CBM, CNKI, VIP, Wanfang, PubMed, EMBASE, and Cochrane Library) were searched until April 2017. The quality of the included studies was evaluated, and meta-analyses were performed using RevMan5.3 and STATA 12.0 software. Moreover, funnel plot and Egger's publication bias plots were analysed to identify publication bias and adverse reactions were reported. A sensitive analysis was carried out according to the quality score.

Results

In all, 40 RCTs involving 4536 patients were selected for this review. The pooled estimates of three studies showed that the benefit to the number of ISRs (NoR) was more substantial for CCM plus RWM than for RWM alone (RR 0.24, 95% CI 0.10 to 0.57, P = 0.001; I² = 0%, P = 0.81). The rate of ISR was significantly lower for CCM plus RWM than for the same RWM alone (RR 0.44, 95% CI 0.37 to 0.53, P < 0.00001; I² = 0%, P = 0.95). CCM plus RWM benefitted the rate of ISR when a CM placebo plus RWM was used as the control intervention (RR 0.34, 95% CI 0.20 to 0.57, P < 0.0001; I² = 0%, P = 0.95). The difference of adverse reactions was not significant. For secondary outcomes, the CCM plus RWM group did not reduce the rates of revascularization and cardiac death, but it did reduce the rate of recurrent angina over the results observed in the RWM alone group. In addition, funnel plot and Egger's publication bias plot indicated that there was publication bias. The association between the use of CCM plus RWM and RWM alone remained significant after the sensitivity analysis excluding studies with low quality score (quality score ⩽ 4) with a pooled RR of 0.41 (95% CI, 0.34–0.50).

Conclusion

Oral CCM plus RWM clearly benefitted patients with percutaneous coronary intervention (PCI) because it prevented and treated ISR better than was observed for either RWM alone or a CM placebo plus RWM.

Therapeutic Options for In-Stent Restenosis

PURPOSE OF REVIEW

In-stent restenosis (ISR) is a complex disease process that became apparent shortly after the introduction of stents into clinical practice. This review seeks to define in-stent restenosis (ISR) as well as to summarize the major treatment options that have been developed and studied over the past two decades.

RECENT FINDINGS

Recent developments in drug-coated balloons and bioresorbable vascular scaffolds have added new potential treatments for ISR. Two recent network meta-analyses performed a head-to-head comparison of all the various treatment modalities in order to identify the best approach to management of ISR. Current data suggests that repeat stenting with second-generation drug-eluting stents is most likely to lead to the best angiographic and clinical outcomes. In situations where repeat stenting is not preferable, drug-coated balloon therapy seems to be a reasonably effective alternative.

Current Management of In-Stent Restenosis

Despite the advent of the drug-eluting stents (DES) and improved stent design, in-stent restenosis (ISR) remains a challenging problem. The currently available options for treatment of ISR include angioplasty alone, repeat stenting with DES or drug-coated balloons. Several recent studies have compared the available options for treating ISR in an attempt to identify the preferred therapeutic strategy. In this review, we will discuss the currently available therapeutic strategies for the management of patients with ISR and the evidence supporting their use.

Evolution of the degradation mechanism of pure zinc stent in the one-year study of rabbit abdominal aorta model

In the present study, pure zinc stents were implanted into the abdominal aorta of rabbits for 12 months. Multiscale analysis including micro-CT, scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM) and histological stainings was performed to reveal the fundamental degradation mechanism of the pure zinc stent and its biocompatibility. The pure zinc stent was able to maintain mechanical integrity for 6 months and degraded 41.75 ± 29.72% of stent volume after 12 months implantation. No severe inflammation, platelet aggregation, thrombosis formation or obvious intimal hyperplasia was observed at all time points after implantation. The degradation of the zinc stent played a beneficial role in the artery remodeling and healing process. The evolution of the degradation mechanism of pure zinc stents with time was revealed as follows: Before endothelialization, dynamic blood flow dominated the degradation of pure zinc stent, creating a uniform corrosion mode; After endothelialization, the degradation of pure zinc stent depended on the diffusion of water molecules, hydrophilic solutes and ions which led to localized corrosion. Zinc phosphate generated in blood flow transformed into zinc oxide and small amounts of calcium phosphate during the conversion of degradation microenvironment. The favorable physiological degradation behavior makes zinc a promising candidate for future stent applications.

Restenosis of the Coronary Arteries: Past, Present, Future Directions

Restenosis is a pathologic response to vascular injury, characterized by neointimal hyperplasia and progressive narrowing of a stented vessel segment. Although advances in stent design have led to a dramatic reduction in the incidence of restenosis, it continues to represent the most common cause of target lesion failure following percutaneous coronary intervention. Efforts to maximize restenosis prevention, through careful consideration of modifiable risk factors and an individualized approach, are critical, as restenosis, once established, can be particularly difficult to treat. Novel approaches are on the horizon that have the potential to alter the natural history of this stubborn disease.

A potential marker of bare metal stent restenosis: monocyte count - to- HDL cholesterol ratio

Background

Oxidation and inflammation play significant roles in the pathogenesis of coronary artery diseases. Monocyte count to high-density lipoprotein (HDL) cholesterol ratio (MHR) is a new marker and has revealed as an indicator of inflammation in the literature. The present study aimed to search the effect of MHR on in-stent restenosis (ISR) in patients with stable or unstable angina pectoris undergoing bare-metal stent (BMS) implantation.

Methods

A total of 468 consecutive stable or unstable angina pectoris patients (mean age 60.3 ± 10.1 and 70 % men) who had undergone successful BMS implantation were included the study. Serum samples were obtained before the procedure.

Results

The mean period between two coronary angiography procedures was 14 ± 7.9 months. The baseline MHR levels were significantly higher in patients that had ISR (odds ratio, 3.64; 95 % confidence interval, 2.45- 4.84; P < 0.001). Stent diameter, the time between the two coronary angiographic studies, uric acid and MHR levels emerged as independent predictors of ISR.

Conclusions

Our results indicate that elevated MHR is an independent and powerful predictor of ISR in patients with stable or unstable angina pectoris who underwent successful BMS implantation.

Analytical modeling of drug dynamics induced by eluting stents in the coronary multi-layered curved domain

Pharmacokinetics induced by drug eluting stents (DES) in coronary walls is modeled by means of a one-dimensional multi-layered model, accounting for vessel curvature and non-homogeneous properties of the arterial tissues. The model includes diffusion mechanisms, advection effects related to plasma filtration through the walls, and bio-chemical drug reactions. A non-classical Sturm-Liouville problem with discontinuous coefficients is derived, whose closed-form analytical solution is obtained via an eigenfunction expansion. Soundness and consistency of the proposed approach are shown by numerical computations based on possible clinical treatments involving both hydrophilic and hydrophobic drugs. The influence of the main model parameters on drug delivery mechanisms is analyzed, highlighting the effects induced by vessel curvature and yielding comparative indications and useful insights into the concurring mechanisms governing the pharmacokinetics.

Clinical Coronary In-Stent Restenosis Follow-Up after Treatment and Analyses of Clinical Outcomes

BACKGROUND

Clinical in-stent restenosis (CISR) is the main limitation of coronary angioplasty with stent implantation.

OBJECTIVE

Describe the clinical and angiographic characteristics of CISR and the outcomes over a minimum follow-up of 12 months after its diagnosis and treatment.

METHODS

We analyzed in 110 consecutive patients with CISR the clinical presentation, angiographic characteristics, treatment and combined primary outcomes (cardiovascular death, nonfatal acute myocardial infarction [AMI]) and combined secondary (unstable angina with hospitalization, target vessel revascularization and target lesion revascularization) during a minimal follow-up of one year.

RESULTS

Mean age was 61 ± 11 years (68.2% males). Clinical presentations included acute coronary syndrome (ACS) in 62.7% and proliferative ISR in 34.5%. CISR was treated with implantation of drug-eluting stents (DES) in 36.4%, Bare Metal Stent (BMS) in 23.6%, myocardial revascularization surgery in 18.2%, balloon angioplasty in 15.5% and clinical treatment in 6.4%. During a median follow-up of 19.7 months, the primary outcome occurred in 18 patients, including 6 (5.5%) deaths and 13 (11.8%) AMI events. Twenty-four patients presented a secondary outcome. Predictors of the primary outcome were CISR with DES (HR = 4.36 [1.44-12.85]; p = 0.009) and clinical treatment for CISR (HR = 10.66 [2.53-44.87]; p = 0.001). Treatment of CISR with BMS (HR = 4.08 [1.75-9.48]; p = 0.001) and clinical therapy (HR = 6.29 [1.35-29.38]; p = 0.019) emerged as predictors of a secondary outcome.

CONCLUSION

Patients with CISR present in most cases with ACS and with a high frequency of adverse events during a medium-term follow-up.

Effects of probucol on restenosis after percutaneous coronary intervention: a systematic review and meta-analysis

BACKGROUND

Restenosis after percutaneous coronary intervention (PCI) is a remained clinical problem which limits long-term success of PCI. Although there was recognition that probucol in treating restenosis after percutaneous transluminal coronary angioplasty, the efficacy of probucol on restenosis after stent-implantation is controversial. So this meta-analysis was conducted to investigate the association between probucol and late restenosis.

METHODS

Articles were assessed by four trained investigators, with divergences resolved by consensus. PubMed, EMBASE, ScienceDirect and the Cochrane Central Register of clinical trials were searched for pertinent studies. Inclusion criteria were random allocated to treatment and a comparison of probucol-treated patients and control patients (not treated with lipid-lowering drug) undergoing PCI.

RESULTS

Fifteen studies with 859 subjects were analyzed. Major outcome, binary angiographic restenosis defined as >50% stenosis upon follow-up angiography, was significantly decreased with probucol treatment (RR = 0.59 [0.43, 0.80] among vessels, P = 0.0007; and RR = 0.52 [0.40, 0.68] among patients, P<0.00001). Probucol also increased the minimal luminal diameter (SMD = 0.45 [0.30, 0.61], P<0.00001) and decreased late loss upon follow-up after 6 months (SMD = -0.41 [-0.60, -0.22], P<0.0001). Moreover, there was a significantly lower incidence of major adverse cardiac events (MACE) in the probucol group than control group (RR = 0.69 [0.51, 0.93], P = 0.01).

CONCLUSION

Probucol is more than a lipid-lowering drug. It is also effective in reducing the risk of restenosis and incidence of MACE after PCI.

Prognostic role of restenosis in 10 004 patients undergoing routine control angiography after coronary stenting

AIM

Routine control angiography is a valuable tool with high-sensitivity in detecting restenosis after coronary stenting. However, the prognostic role of restenosis is still controversial. We investigated the impact of restenosis on 4-year mortality in patients undergoing routine control angiography after coronary stenting.

METHODS AND RESULTS

All the patients undergoing successful implantation of coronary stents for de novo lesions from 1998 to 2009 and routine control angiography after 6-8 months at two centres in Munich, Germany were studied. Restenosis was defined as diameter stenosis ≥50% in the in-segment area at follow-up angiography. The primary outcome was 4-year mortality. The study included 10 004 patients with 15 004 treated lesions. Restenosis was detected in 2643 (26.4%) patients. Overall, there were 702 deaths during the follow-up. Of these, 218 deaths occurred among patients with restenosis and 484 deaths occurred among patients without restenosis [unadjusted hazard ratio: HR: 1.19; (95% confidence interval CI: 1.02-1.40); P = 0.03]. The Cox proportional hazards model adjusting for other variables identified restenosis as an independent correlate of 4-year mortality [HR: 1.23; (95% CI: 1.03-1.46); P = 0.02]. Other independent correlates of 4-year mortality were age [for each 10-year increase, HR: 2.34; (95% CI: 2.12-2.60); P < 0.001], diabetes mellitus [HR: 1.68; (95% CI: 1.41-1.99); P < 0.001], current smoking habit [HR: 1.39; (95% CI: 1.09-1.76); P = 0.01], and left ventricular ejection fraction [for each 5% decrease, HR: 1.39; (95% CI: 1.31-1.48); P < 0.001].

CONCLUSIONS

In this large cohort of patients, the presence of restenosis at follow-up angiography after coronary stenting was predictive of 4-year mortality. Whether routine control angiography after coronary stenting is beneficial and influences outcomes should be evaluated by properly designed randomized trials.

Current treatment of in-stent restenosis

Management of patients with in-stent restenosis (ISR) remains an important clinical problem. Although drug-eluting stents (DES) have drastically reduced the incidence of ISR, treatment of DES-ISR is particularly challenging. ISR mainly results from aggressive neointimal proliferation, but recent data also suggest that neoatherosclerosis may play an important pathophysiological role. Intracoronary imaging provides unique insights to unravel the underlying substrate of ISR and may be used to guide repeated interventions. In this paper, we systematically reviewed clinical trial data with currently available therapeutic modalities, including DES and drug-coated balloons, in patients presenting with ISR within bare-metal stents or DES.

Zotarolimus- and paclitaxel-eluting stents in an all-comer population in China: the RESOLUTE China randomized controlled trial

OBJECTIVES

This study sought to compare clinical outcomes and angiographic findings using the Resolute zotarolimus-eluting stent (R-ZES) (Medtronic, Santa Rosa, California) versus the Taxus Liberte paclitaxel-eluting stent (PES) (Boston Scientific, Natick, Massachusetts) in an all-comer Chinese population.

BACKGROUND

Concerns regarding restenosis risk led to new-generation drug-eluting stents (DES) designed for use in patients with complex clinical or lesion characteristics. In-stent late lumen loss (LLL) is a measure of restenosis risk.

METHODS

Patients with an indication for treatment with a DES were randomized in a 1:1 ratio to placement of at least 1 R-ZES or PES with minimal exclusions. The primary endpoint was angiographic in-stent LLL at 9 months post-procedure. Clinical endpoints at 12 months are compared between the 2 stents.

RESULTS

A total of 198 patients received a R-ZES, and 202 patients received a PES. Most patients were male; 25.8% and 29.2% of R-ZES and PES patients, respectively, had diabetes. Over 70% of lesions in both cohorts were American College of Cardiology/American Heart Association lesion classification Type B2 and C (B2/C). In-stent LLL was 0.16 ± 0.38 mm for R-ZES and 0.33 ± 0.52 mm for PES at 9 months (p < 0.001; 95% confidence interval [CI]: -0.26 to -0.08). The rates of clinically driven target lesion revascularization were 1.5% for R-ZES and 7.0% for PES (p = 0.011). The rate of target lesion failure was 5.6% for R-ZES and 11% for PES (p = 0.068).

CONCLUSIONS

In an all-comers Chinese population, 9-month in-stent LLL was significantly less with R-ZES compared with PES, which was reflected in lower revascularization rates at 12 months for the R-ZES patients. Results are consistent with previous clinical trials of the R-ZES in all-comer populations. (Resolute Zotarolimus-Eluting Stent Versus the Taxus Liberte Paclitaxel-Eluting Stent for Percutaneous Coronary Intervention in China [R-China RCT]; NCT01334268).

Another view of personalized medicine: optimizing stent selection on the basis of predicted benefit in percutaneous coronary intervention

Drug-eluting stents (DES) decrease the risk of restenosis compared to bare metal stents (BMS) for percutaneous coronary intervention (PCI). However, their use requires patients to take prolonged dual antiplatelet therapy that increases bleeding risk and without which, patients have an increased risk of developing stent thrombosis. In light of these competing risks, understanding which patients derive the greatest benefit of DES compared to BMS is essential for guiding therapy. We review recent efforts to predict the magnitude of the restenosis benefit of DES compared to BMS for individual patients. Understanding and predicting the likelihood of benefit for individual patients is essential to rational decision making with regard to the type of stent to use during PCI and will serve to increase the value of the health care that clinicians deliver.

Systematic Review of Chinese Herbal Medicines for Preventing in-Stent Coronary Restenosis after Percutaneous Coronary Intervention

Percutaneous coronary intervention (PCI) with stent placement is a standard treatment for coronary artery disease (CAD). In-stent restenosis after PCI remains a challenging clinical problem. In China, Chinese herbal medicines (CHMs) are widely used for preventing restenosis. This paper systematically reviewed the literature on the effectiveness and safety of CHMs in preventing restenosis after PCI in patients with CAD. Electronic databases were searched for randomized controlled trials that compared CHMs plus RWM with the same RWM plus placebo in preventing restenosis after PCI. A total of 52 trials (4905 patients) on 34 CHMs met the inclusion criteria and were analyzed. Ten trials had low risk of bias. Methodological quality of included trials was generally poor. Meta-analysis showed that at the end of at least 3 months' followup, CHMs plus RWM could significantly reduce restenosis rate, cardiac mortality, recurrence rate of angina, acute myocardial infarction, numbers of repeat PCI, and numbers of coronary artery bypass graft. Reported adverse events included gastrointestinal upset, granulocytopenia, and increased alanine transaminase (ALT). CHMs may help prevent restenosis, thus reducing cardiac mortality after PCI. Caution should be exercised in drawing a definitive conclusion due to the poor methodological quality of the trials reviewed.

Soluble receptors for advanced glycation end products (sRAGE) as a predictor of restenosis following percutaneous coronary intervention

BACKGROUND

Interaction of advanced glycation end products (AGEs) with their receptor (RAGE) increases expression of inflammatory mediators (tumor necrosis factor alpha [TNF-α] and soluble vascular cell adhesion molecule-1 [sVCAM-1]) and induces oxygen radicals that are implicated in atherosclerosis. Balloon-injury-induced atherosclerosis is associated with increased expression of AGEs and RAGE. The soluble receptor for AGE (sRAGE), which acts as a decoy for RAGE ligands (AGEs), prevents atherosclerosis in this model.

HYPOTHESIS

We evaluated: 1) whether post-percutaneous coronary intervention (PCI) restenosis is associated with low pre-PCI serum sRAGE, high serum AGEs, TNF-α, and sVCAM-1, and high AGE/sRAGE ratio; 2) whether pre-PCI and post-PCI levels of these markers are similar in patients with or without restenosis; and 3) whether sRAGE and AGE/sRAGE ratio have predictive value for post-PCI restenosis.

METHODS

Angiography was performed in 46 patients with non-ST-segment elevation myocardial infarction for assessment of restenosis. Serum sRAGE, AGEs, TNF-α, and sVCAM-1 were measured in these patients and 20 control subjects.

RESULTS

: Nineteen of the 46 patients developed post-PCI restenosis, which was associated with lower sRAGE and higher TNF-α and sVCAM-1 levels, and higher AGE/sRAGE ratio compared with patients without restenosis. Pre-PCI and post-PCI levels of these biomarkers were similar in both groups, except in patients with restenosis, in whom the post-PCI level of sRAGE was lower and TNF-α was higher than the pre-PCI levels. The sensitivity and negative predictive value of sRAGE were 100%, and were higher than those of AGE/sRAGE ratio in identifying post-PCI restenosis.

CONCLUSIONS

Both low serum sRAGE levels and high AGE/sRAGE ratio have predictive value for post-PCI restenosis.

The effect of stent porosity and strut shape on saccular aneurysm and its numerical analysis with lattice Boltzmann method

The analysis of a flow pattern in cerebral aneurysms and the effect of stent strut shapes are presented in this article. The treatment of cerebral aneurisms with a porous stent has recently been proposed as a minimally invasive way to prevent rupture and favor coagulation mechanism inside the aneurism. The efficiency of stent is related to several parameters, including porosity and stent strut shapes. The goal of this article is to study the effect of the stent strut shape and porosity on the hemodynamic properties of the flow inside an aneurysm using a numerical analysis. In this study, we use the concept of flow reduction to characterize the stent efficiency. Also, we use the lattice Boltzmann method (LBM) of a non-Newtonian blood flow. To resolve the characteristics of a highly complex flow, we use an extrapolation method for the wall and stent boundary. To ease the code development and facilitate the incorporation of new physics, a scientific programming strategy based on object-oriented concepts is developed. Reduced velocity, smaller average vorticity magnitude, smaller average shear rate, and increased viscosity are observed when the proposed stent shapes and porosities are used. The rectangular stent is observed to be optimal and to decrease the magnitude of the velocity by 89.25% in the 2D model and 53.92% in the 3D model in the aneurysm sac. Our results show the role of the porosity and stent strut shape and help us to understand the characteristics of stent strut design.

Preventing restenosis in early drug-eluting stent era: recent developments and future perspectives

Restenosis is the major limitation of the successful therapy of percutaneous coronary intervention (PCI) for patients with coronary artery disease. The problem was appreciated in the late 1970s to early 1980s. Only in recent years, anti-restenotic therapy has achieved a breakthrough with the development of drug-eluting stents. Here, we provide an overview about pathological mechanisms of restenosis after PCI. Present therapeutic approaches to overcome restenosis and recent clinical results are revisited, and some major concerns in the post-drug-eluting stent era are discussed.