Long-term clinical outcomes after drug-eluting and bare-metal stenting in Massachusetts

The Effect of Drug-Eluting Stents on Target Lesion Revascularization in Native Coronary Arteries: Results from the NORSTENT Randomized Study

BACKGROUND

The NORSTENT trial randomized 9,013 patients to percutaneous coronary intervention (PCI) with a drug-eluting stent (DES) or bare-metal stent (BMS) with 5-year follow-up. No difference was found in the composite primary outcome of death from any cause and nonfatal spontaneous myocardial infarction after a median of 5 years of follow-up. Secondary outcomes included repeat revascularizations, which were reduced by DES. We report the occurrence of target lesion revascularization (TLR) in time and across demographic and clinical subgroups in patients with lesions in native coronary arteries (n = 8,782).

RESULTS

Clinically driven TLR was performed on 488 (5.6%) of the 8,782 patients during 5 years of follow-up. Male gender, older age, visible thrombus in the lesion, and larger stent diameter were associated with less TLR; multivessel disease and longer stents were associated with a higher risk of TLR. There was a substantial and highly significant reduction of the risk of any TLR after 5 years in the DES group (hazard ratio [HR] 0.44, 95% confidence interval [CI] 0.36-0.52], p < 0.001). The effect of DES on TLR was limited in time to the first 2 years in the study with no evidence of a later rebound effect. The reduction in TLR after DES insertion was consistent across subgroups defined by gender, age, diabetes status, renal function, and lesion and stent characteristics. The number needed to treat with DES (vs. BMS) to prevent 1 TLR ranged from 4 to 110 across clinically relevant subgroups.

CONCLUSION

DES have a time-limited effect on the rate of TLR, but with a substantial and highly significant reduction in the first 2 years after the procedure. This effect was found to be consistent across all important clinical subgroups.

Nonparametric Bayesian Instrumental Variable Analysis: Evaluating Heterogeneous Effects of Coronary Arterial Access Site Strategies

Percutaneous coronary interventions (PCIs) are nonsurgical procedures to open blocked blood vessels to the heart, frequently using a catheter to place a stent. The catheter can be inserted into the blood vessels using an artery in the groin or an artery in the wrist. Because clinical trials have indicated that access via the wrist may result in fewer post procedure complications, shortening the length of stay, and ultimately cost less than groin access, adoption of access via the wrist has been encouraged. However, patients treated in usual care are likely to differ from those participating in clinical trials, and there is reason to believe that the effectiveness of wrist access may differ between males and females. Moreover, the choice of artery access strategy is likely to be influenced by patient or physician unmeasured factors. To study the effectiveness of the two artery access site strategies on hospitalization charges, we use data from a state-mandated clinical registry including 7,963 patients undergoing PCI. A hierarchical Bayesian likelihood-based instrumental variable analysis under a latent index modeling framework is introduced to jointly model outcomes and treatment status. Our approach accounts for unobserved heterogeneity via a latent factor structure, and permits nonparametric error distributions with Dirichlet process mixture models. Our results demonstrate that artery access in the wrist reduces hospitalization charges compared to access in the groin, with a higher mean reduction for male patients.

In-stent restenosis of drug-eluting stents: clinical presentation and outcomes in a real-world scenario

BACKGROUND

Drug-eluting stents (DES) have substantially reduced the incidence of coronary in-stent restenosis (ISR), but the problem persists. Clinical presentation and outcomes of DES-ISR in a real-world scenario remains underreported.

RESULTS

In this retrospective study, we examined medical records of 191 consecutive patients with DES-ISR (210 ISR lesions) hospitalized between January 2013 and December 2017. ISR clinical presentation was classified as acute coronary syndrome (ACS) or non-ACS. Clinical, angiographic features and 1-year outcomes [composite of death, myocardial infarction (MI) and repeat-target lesion revascularization] for these two groups were compared. The mean age of study population was 61 ± 10 years and 81.2% were males. ACS was the dominant clinical presentation mode occurring in 118 (61.8%) patients. MI was seen in 66 (34.6%) patients. Female gender (odds ratio, 2.71; 95% confidence interval [CI], 1.13-6.52; P = 0.026) and chronic kidney disease (odds ratio, 3.85; 95% CI, 1.05-14.20; P = 0.043) correlated significantly with ACS ISR presentation. A majority [104 (54.5%)] of patients underwent percutaneous coronary intervention (PCI), of whom 72 (69.2%) received a new DES. The rest either underwent CABG (26.2%) or received medical therapy (19.4%). Patients presenting with ACS had a significantly worse clinical outcome at 1-year follow-up (ACS versus non-ACS presentation: hazard ratio [HR], 2.66; 95% CI, 1.09-6.50; P = 0.032).

CONCLUSIONS

DES-ISR presents most commonly as ACS. Female gender and chronic kidney disease seem to be associated with ACS presentation. ACS presentation of ISR is associated with worse 1-year outcomes. Early identification of those with ACS risk and closer follow-up may improve outcomes.

Danhong injection mobilizes endothelial progenitor cells to repair vascular endothelium injury via upregulating the expression of Akt, eNOS and MMP-9

BACKGROUD

Endothelial progenitor cells (EPCs) have been characterized as one of the key effectors of endothelial healing. The effect of Danhong injection (DHI), the most widely prescribed Chinese medicine for coronary heart disease (CHD), on EPCs mobilization remains unclear.

PURPOSE

We aimed to assess the effect of DHI on EPCs mobilization to repair percutaneous coronary intervention (PCI) induced vascular injury, and to investigate the characteristics and potential mechanism of DHI on EPCs mobilization.

METHOD

Forty-two patients with CHD underwent PCI and received stent implantation were enrolled in a Phase II clinical trials. All patients received routine western medical treatment after PCI, patients of DHI group received DHI in addition. The levels of CECs, cytokines (vWF, IL-6, CRP) and EPCs were analyzed at baseline, post-PCI and after treatment. To investigate the characteristics of DHI on EPCs mobilization, 12 healthy volunteers received intravenous infusion of DHI once and the other 12 received for 7 days. EPCs enumeration were done at a series of time points. At last we tested the effect of DHI and three chemical constituents of DHI (danshensu; lithospermic acid, LA; salvianolic acid D, SaD) on EPCs level and expression of Akt, eNOS and MMP-9 in bone marrow cells of myocardial infarction (MI) mice.

RESULTS

In the DHI group the angina symptoms were improved, the levels of cytokines and CECs were reduced; while EPCs population was increased after treatment. In the phase I clinical trials, EPCs counts reached a plateau phase in 9 h and maintained for more than 10 h after a single dose. After continuous administration, EPCs levels plateaued on the 3rd or 4th day, and maintain till 1 day after the withdrawal, then its levels gradually declined. DHI treatment induced a timely dependent mobilization of EPCs. DHI promoted EPCs mobilization via upregulating the expression of Akt, eNOS and MMP-9 in BM. LA and SaD have played a valuable role in EPCs mobilization.

CONCLUSION

These initial results demonstrated that DHI is effective in alleviating endothelial injury and promoting endothelial repair through enhancing EPCs mobilization and revealed the effect feature and possible mechanisms of DHI in mobilizing EPCs.

Bayesian propensity scores for high-dimensional causal inference: A comparison of drug-eluting to bare-metal coronary stents

High-dimensional data provide many potential confounders that may bolster the plausibility of the ignorability assumption in causal inference problems. Propensity score methods are powerful causal inference tools, which are popular in health care research and are particularly useful for high-dimensional data. Recent interest has surrounded a Bayesian treatment of propensity scores in order to flexibly model the treatment assignment mechanism and summarize posterior quantities while incorporating variance from the treatment model. We discuss methods for Bayesian propensity score analysis of binary treatments, focusing on modern methods for high-dimensional Bayesian regression and the propagation of uncertainty. We introduce a novel and simple estimator for the average treatment effect that capitalizes on conjugacy of the beta and binomial distributions. Through simulations, we show the utility of horseshoe priors and Bayesian additive regression trees paired with our new estimator, while demonstrating the importance of including variance from the treatment regression model. An application to cardiac stent data with almost 500 confounders and 9000 patients illustrates approaches and facilitates comparison with existing alternatives. As measured by a falsifiability endpoint, we improved confounder adjustment compared with past observational research of the same problem.

In-Stent Restenosis of Drug-Eluting Stents Compared With a Matched Group of Patients With De Novo Coronary Artery Stenosis

Drug-eluting stents (DES) significantly reduced the incidence of in-stent restenosis (ISR). However, ISR still exists in the contemporary DES era. Previously deemed to be a benign process, ISR leads to complex presentation and intervention. This study aimed to compare the presentation and outcome of DES-ISR versus de novo lesions. We performed a retrospective analysis of 11,666 patients receiving percutaneous coronary intervention from 2003 to 2017 and divided them into 2 groups by de novo stenosis and ISR. They were matched based on common cardiovascular risk factors at a 4:1 ratio, respectively. After matching, a total of 1,888 patients with 3,126 de novo lesions and 472 patients with 508 ISR lesions were analyzed. Patients with ISR presented more often with unstable angina (61% vs 45%, p <0.001) and less often with myocardial infarction (6% vs 14%, p <0.001). One-year composite major adverse cardiovascular event, defined as death, Q-wave myocardial infarction, and target vessel revascularization, was 10% in the de novo group and 17% in the ISR group (hazard ratio 1.98, 95% confidential interval 1.58 to 2.46, p <0.001). After adjusting for myocardial infarction presentation, hazard ratio of major adverse cardiovascular events was still higher for the ISR group at 1 year (2.03, 95% confidential interval 1.62 to 2.55, p <0.001). ISR of DES remains a therapeutic challenge and leads to complex presentation and worse outcomes compared with matched de novo patients. These data show that DES-ISR demands better appreciation and prevention with more precise stent technique and should motivate the continued development of fully bioresorbable scaffolds.

Cleaved high-molecular-weight kininogen inhibits neointima formation following vascular injury

Cleaved high-molecular-weight kininogen (HKa) or its peptide domain 5 (D5) alone exert anti-adhesive properties in vitro related to impeding integrin-mediated cellular interactions. However, the anti-adhesive effects of HKa in vivo remain elusive. In this study, we investigated the effects of HKa on leukocyte recruitment and neointima formation following wire-induced injury of the femoral artery in C57BL/6 mice. Local application of HKa significantly reduced the accumulation of monocytes and also reduced neointimal lesion size 14 days after injury. Moreover, C57BL/6 mice transplanted with bone marrow from transgenic mice expressing enhanced green fluorescence protein (eGFP) showed a significantly reduced accumulation of eGFP+-cells at the arterial injury site and decreased neointimal lesion size after local application of HKa or the polypeptide D5 alone. A differentiation of accumulating eGFP+-cells into highly specific smooth muscle cells (SMC) was not detected in any group. In contrast, application of HKa significantly reduced the proliferation of locally derived neointimal cells. In vitro, HKa and D5 potently inhibited the adhesion of SMC to vitronectin, thus impairing their proliferation, migration, and survival rates. In conclusion, application of HKa or D5 decreases the inflammatory response to vascular injury and exerts direct effects on SMC by impeding the binding of integrins to extracellular matrix components. Therefore, HKa and D5 may hold promise as novel therapeutic substances to prevent neointima formation.

Early and aggressive ISR with a polymer- and carrier-free drug-coated stent system

The LEADERS FREE trial concluded that the polymer free drug-coated BioFreedom™ stent appeared to be both safer and more effective than bare-metal stents (BMS) with an ISR rate comparable to traditional DES without the need for prolonged DAPT. We implanted 45 BioFreedom™ stents in 34 patients over a 4-month period. 4 patients represented early (106–238 days after the implant procedure) with angina symptoms and severe ISR was detected in all patients. The rate of severe and early ISR detected in our patient population of 11.8% is comparable to that of traditional BMS. Further studies are warranted.

Association between plasma BMP-2 and in-stent restenosis in patients with coronary artery disease

OBJECTIVE

This study aimed to assess the association between plasma bone morphogenetic protein-2 (BMP-2) level and in-stent restenosis in patients with coronary artery disease.

METHODS

A total of 96 patients who underwent percutaneous coronary intervention (PCI) and were followed up after PCI were enrolled in this study. 47 patients diagnosed with in-stent restenosis (ISR) were recruited to ISR group and 49 patients without ISR were recruited to Control group according to the results of coronary angiography (CAG). Baseline characteristic data were collected, and plasma BMP-2 level was evaluated. The results were analyzed using logistic regression.

RESULTS

There were 47 patients in the ISR group and 49 patients in the Control group. Plasma levels of BMP-2 were higher in the ISR group than in the non-ISR group [20.96 (18.44, 27.05) pg/ml vs. 29.53 (25.03, 34.07) pg/ml, P<0.01]. Furthermore, the ISR group had significantly longer stent lengths and lower stent diameters than the Control group (P<0.01 and P<0.01, respectively). In multivariate analysis, BMP-2 level, diabetes, stent length and stent diameter were independently associated with ISR [odds ratio (OR)=1.11, 95% confidence interval (CI)=1.03-1.18, P<0.01; OR=4.75, 95% CI=(1.44-15.61), P=0.01; OR=1.06, 95% CI=(1.02-1.11), P<0.01; and OR=0.15, 95% CI=(0.02-0.95), P=0.04, respectively].

CONCLUSIONS

Increased BMP-2 levels were independently associated with ISR in patients with coronary artery disease. Plasma BMP-2 may be useful in predicting ISR.

Efficacy of various percutaneous interventions for in-stent restenosis: comprehensive network meta-analysis of randomized controlled trials

BACKGROUND

In-stent restenosis (ISR) remains a difficult problem in interventional cardiology. The relative efficacy and safety of available interventions is not clear. We aimed to perform a network meta-analysis using both direct evidence and indirect evidence to compare all available interventions.

METHODS AND RESULTS

We systematically searched electronic databases for randomized trials comparing ≥2 treatments for ISR. A network meta-analysis was performed using a Bayesian approach. Eleven treatments were compared in 31 studies with 8157 patient-years follow-up. Compared with balloon angioplasty, everolimus-eluting stent (hazard ratio [95% credibility interval], 0.13 [0.048-0.35]), paclitaxel-eluting balloon (0.32 [0.20-0.49]), paclitaxel-eluting cutting balloon (0.054 [0.0017-0.5]), paclitaxel-eluting stent (0.39 [0.24-0.62]), and sirolimus-eluting stent (0.32 [0.18-0.50]) are associated with lower target vessel revascularization. Balloon angioplasty is not different from cutting balloon (0.73 [0.31-1.5]), excimer laser (0.89 [0.29-2.7]), rotational atherectomy (0.96 [0.53-1.7]), and vascular brachytherapy (0.60 [0.35-1.0]). In drug-eluting stent ISR, balloon angioplasty was inferior to everolimus-eluting stent (0.19 [0.049-0.76]), paclitaxel-eluting balloon (0.43 [0.18-0.80]), paclitaxel-eluting stent (0.35 [0.13-0.76]), and sirolimus-eluting stent (0.36 [0.11-0.86]) for target vessel revascularization. There was no difference between treatments in probable or definitive stent thrombosis. The results of binary restenosis and target lesion revascularization were similar. Paclitaxel-eluting cutting balloon, everolimus-eluting stent, and paclitaxel-eluting balloon have the highest probability of being in the top 3 treatments based on low target lesion revascularization, but there was no statistical significant difference between them.

CONCLUSIONS

Balloon angioplasty is inferior to all drug-eluting treatments for ISR, including drug-eluting stent ISR. Drug-eluting stent, particularly everolimus-eluting stent, or paclitaxel-eluting cutting balloon and paclitaxel-eluting balloon should be preferred for treating ISR.

The role of angiographic follow-up after percutaneous coronary intervention

In the early days of coronary angioplasty, follow-up coronary angiography was often performed to assess restenosis. Angiographic restenosis has been shown to be associated with worse clinical outcomes, though the exact causality has yet to be determined. Numerous studies have repeatedly demonstrated that routine follow-up coronary angiography increases the incidence of target lesion revascularization without a clear reduction in mortality or myocardial infarction. Despite the lack of proven benefit of angiographic follow-up, routine follow-up coronary angiography is still being performed in certain countries and facilities. There are several factors that might explain the lack of benefit of angiographic follow-up: 1) lower incidence of stent failure in the current drug-eluting stent era has attenuated the net clinical benefit of follow-up angiography. 2) Angiographic restenosis might not lead to myocardial ischemia. 3) Patients that do have functionally significant restenosis are often referred for coronary angiography due to clinical indications such as intractable angina. 4) Absence of restenosis at the time of follow-up angiography does not exclude future restenosis. The absence of proven benefit in unselected populations does not necessarily preclude the presence of benefit in selected population, and there may be a subgroup of patients who can benefit from angiographic follow-up such as those with a large myocardial ischemic territory or those at very high risk of restenosis. Until there is more clinical evidence with respect to follow-up angiography, the decision of whether or not to perform it routinely in selected high-risk population should entail an in-depth discussion with the patient.

Intracoronary brachytherapy for in-stent restenosis of drug-eluting stents

PURPOSE

Given the limited salvage options for in-stent restenosis (ISR) of drug-eluting stents (DES), our high-volume cardiac catheterization laboratory has been performing intracoronary brachytherapy (ICBT) in patients with recurrent ISR of DES. This study analyzes their baseline characteristics and assesses the safety/toxicity of ICBT in this high-risk population.

METHODS AND MATERIALS

A retrospective analysis of patients treated with ICBT between September 2012 and December 2014 was performed. Patients with ISR twice in a single location were eligible. Procedural complications included vessel dissection, perforation, tamponade, slow/absent blood flow, and vessel closure. Postprocedural events included myocardial infarction, coronary artery bypass graft, congestive heart failure, stroke, bleeding, thrombosis, embolism, dissection, dialysis, or death occurring within 72 hours. A control group of patients with 2 episodes of ISR at 1 location who underwent percutaneous coronary intervention without ICBT was identified. Unpaired t tests and χ2 tests were used to compare the groups.

RESULTS

There were 134 (78%) patients in the ICBT group with 141 treated lesions and 37 (22%) patients in the control group. There was a high prevalence of hyperlipidemia (>95%), hypertension (>95%), and diabetes (>50%) in both groups. The groups were well-balanced with respect to age, sex, and pre-existing medical conditions, with the exception of previous coronary artery bypass graft being more common the ICBT group. Procedural complication rates were low in the control and ICBT groups (0% vs 4.5%, P = .190). Postprocedural event rates were low (<5%) in both groups. Readmission rate at 30 days was 3.7% in the ICBT group and 5.4% in the control group (P = .649).

CONCLUSIONS

This is the largest recent known series looking at ICBT for recurrent ISR of DES. ICBT is a safe treatment option with similarly low rates (<5%) of procedural and postprocedural complications compared with percutaneous coronary intervention alone. This study establishes the safety of ICBT in a high-risk patient cohort.

Treatment strategies for coronary in-stent restenosis: systematic review and hierarchical Bayesian network meta-analysis of 24 randomised trials and 4880 patients

STUDY QUESTION

What is the most safe and effective interventional treatment for coronary in-stent restenosis?

METHODS

In a hierarchical Bayesian network meta-analysis, PubMed, Embase, Scopus, Cochrane Library, Web of Science, ScienceDirect, and major scientific websites were screened up to 10 August 2015. Randomised controlled trials of patients with any type of coronary in-stent restenosis (either of bare metal stents or drug eluting stents; and either first or recurrent instances) were included. Trials including multiple treatments at the same time in the same group or comparing variants of the same intervention were excluded. Primary endpoints were target lesion revascularisation and late lumen loss, both at six to 12 months. The main analysis was complemented by network subanalyses, standard pairwise comparisons, and subgroup and sensitivity analyses.

STUDY ANSWER AND LIMITATIONS

Twenty four trials (4880 patients), including seven interventional treatments, were identified. Compared with plain balloons, bare metal stents, brachytherapy, rotational atherectomy, and cutting balloons, drug coated balloons and drug eluting stents were associated with a reduced risk of target lesion revascularisation and major adverse cardiac events, and with reduced late lumen loss. Treatment ranking indicated that drug eluting stents had the highest probability (61.4%) of being the most effective for target lesion vascularisation; drug coated balloons were similarly indicated as the most effective treatment for late lumen loss (probability 70.3%). The comparative efficacy of drug coated balloons and drug eluting stents was similar for target lesion revascularisation (summary odds ratio 1.10, 95% credible interval 0.59 to 2.01) and late lumen loss reduction (mean difference in minimum lumen diameter 0.04 mm, 95% credible interval -0.20 to 0.10). Risks of death, myocardial infarction, and stent thrombosis were comparable across all treatments, but these analyses were limited by a low number of events. Trials had heterogeneity regarding investigation periods, baseline characteristics, and endpoint reporting, with a lack of information at long term follow-up. Direct and indirect evidence was also inconsistent for the comparison between drug eluting stents and drug coated balloons.

WHAT THIS STUDY ADDS

Compared with other currently available interventional treatments for coronary in-stent restenosis, drug coated balloons and drug eluting stents are associated with superior clinical and angiographic outcomes, with a similar comparative efficacy.

FUNDING, COMPETING INTERESTS, DATA SHARING

This study received no external funding. The authors declare no competing interests. No additional data available.

New Endoplasmic Reticulum Stress Regulator, Gipie, Regulates the Survival of Vascular Smooth Muscle Cells and the Neointima Formation After Vascular Injury

Objective—

The accumulation of unfolded protein in the endoplasmic reticulum (ER) initiates an adaptive stress response, termed the unfolded protein response. Previous studies suggested that ER stress might be involved in the formation of neointima after vascular injury. We recently discovered a novel regulator of ER stress, 78-kDa glucose-regulated protein–interacting protein induced by ER stress (Gipie). The objective of this study was to elucidate the role of Gipie using models of vascular disease.

Approach and Results—

We investigated the functions of Gipie in cultured vascular smooth muscle cells (VSMCs) and in a vascular injury model of a rat carotid artery. The expression of Gipie was predominantly detected in synthetic VSMCs and to a much lesser extent in contractile VSMCs, which was augmented by treatment with thapsigargin. Gipie knockdown increased the phosphorylation levels of c-Jun N-terminal kinase and the number of apoptotic cells under ER stress. Moreover, Gipie knockdown decreased the mature form of collagen I in synthetic VSMCs. The expression of Gipie was rarely detected in the medial VSMCs of the intact carotid artery, whereas it was detected in most of the neointimal cells and some of the medial VSMCs after balloon injury. Depletion of Gipie in the rat carotid artery attenuated the neointimal thickening, which was accompanied by increased cell death in the neointima. Conversely, overexpression of Gipie augmented the neointimal thickening.

Conclusions—

Gipie participates in the ER stress response in VSMCs and plays an important role in neointima formation after vascular injury.

How to balance risks and benefits in the management of CKD patients with coronary artery disease

Chronic kidney disease (CKD) is associated with a high burden of coronary artery disease (CAD), which remains the most common cause of morbidity and mortality in CKD patients. Although the management of CAD is more challenging in patients with CKD than in the general population, and coupled with concerns about further deterioration of renal function and therapy-related toxic effects, CKD patients and those receiving dialysis have not traditionally been included in randomized trials evaluating either medical or revascularization therapies. Thus, only scant data from small prospective studies or retrospective analyses of controlled trials and registries are available, and to date no optimal treatment approach has been defined for this subgroup of patients. However, they potentially have much to gain from the pharmacological, interventional, and surgical strategies used in the general population. Thus, the objective of this review is to summarize the current evidence regarding the management of CAD in CKD patients, in particular with respect to uncertainties regarding coronary revascularization options, and their risk-benefit relationship in such a high-risk population.

Control Outcomes and Exposures for Improving Internal Validity of Nonrandomized Studies

OBJECTIVE

Control outcomes and exposures can improve internal validity of nonrandomized studies by assessing residual bias in effect estimates. Control outcomes are those expected to have no treatment effect or the opposite effect of the primary outcome. Control exposures are treatments expected to have no effect on the primary outcome. We review examples of control outcomes and exposures from prior studies and provide recommendations for conducting and reporting these analyses.

DATA SOURCES AND STUDY DESIGN

Review in Google Scholar and Medline of research studies employing control outcomes or exposures. We abstracted publication year, control outcome, control exposure, primary outcome, primary exposure, control outcome/exposure effect, proposed source of bias, and causal criteria.

PRINCIPAL FINDINGS

There is inconsistent terminology for these concepts, making study identification challenging. Six of 11 studies found null associations between treatments and negative control outcomes/exposures, providing greater confidence that the primary study findings were not biased. Five studies found unexpected associations, suggesting bias in the primary association.

CONCLUSIONS

The rigor of nonrandomized studies can be improved with inclusion of control outcomes and exposures for bias detection. Given ongoing concern about clinical and policy inferences from nonrandomized studies, we recommend adoption of these measurement tools.

Vascular injury and repair: a potential target for cell therapies

ABSTRACT 

Whether due to atherosclerotic disease or mechanical intervention, vascular injury is a frequently encountered pathology in cardiovascular medicine. The past decade has seen growing interest in the role of circulating endothelial progenitor cells in vessel recovery postinjury. Despite this, the definition, origin and potential role of endothelial progenitor cells in vascular regeneration remains highly controversial. While animal work has shown early promise, evidence of a therapeutic role for endothelial progenitor cells in humans remains elusive. To date, clinical trials involving direct cell administration, growth factor therapy and endothelial cell capture stents have largely been disappointing, although this may in part reflect limitations in study design. This article will outline the pathophysiological mechanisms of vascular injury with an emphasis on endothelial progenitor cell biology and the potential therapeutic role of this exciting new field.

Drug-coated balloon angioplasty for drug-eluting stent restenosis: insight from randomized controlled trials

BACKGROUND

The best treatment option for drug-eluting stent (DES) restenosis has not been established. We performed a meta-analysis to assess the clinical efficacy of drug-coated balloon (DCB) for the treatment of DES restenosis.

METHODS

Trials were identified through a literature search from January 2005 through April 2014. All randomized controlled trials were eligible for inclusion if they compared DCB with a control treatment (plain old balloon angioplasty [POBA] or DES) in patients with DES restenosis.

RESULTS

Five studies and a total of 864 patients were included in this analysis. Most end-points were significantly reduced for DCB compared with the control groups. For major adverse cardiac events, the relative risk (RR) was 0.49 (P = 0.012); for target lesion revascularization, it was 0.50 (P = 0.044); for recurrent restenosis, it was 0.41 (P = 0.002). There was a lower mortality for DCB (RR 0.29; P = 0.017). The incidence of myocardial infarction was numerically lower, but without statistical significance (RR 0.76; P = 0.55). The DCB effect was more pronounced when compared with POBA than when compared with DES.

CONCLUSIONS

This meta-analysis showed that DCB was superior to POBA and comparable to DES for treatment of DES restenosis. The findings in this meta-analysis cannot be extrapolated to DCB in general, because all DCB used in trials included was a single brand of paclitaxel-coated balloon.

Prevention of neointimal formation after angioplasty using nuclear factor-κB decoy oligodeoxynucleotide-coated balloon catheter in rabbit model

BACKGROUND

Despite the advent of drug-eluting stents, restenosis after endovascular intervention is still a major limitation in the treatment of cardiovascular disease. To regulate the multiple biological mechanisms underlying restenosis, we focused on inhibition of an important transcription factor, nuclear factor-kappaB (NFκB), using a decoy strategy.

METHODS AND RESULTS

For site-specific application of NFκB decoy oligodeoxynucleotides into target vessels during angioplasty, we developed a balloon catheter-based delivery system combined with biocompatible nanoparticles as oligodeoxynucleotides carriers. To clarify the therapeutic effect at the site of neointima, balloon angioplasty of the rabbit carotid arteries was performed at 4 weeks after initial endothelial denudation. This delivery system exhibited successful transfer of fluorescence-labeled nanospheres into the neointima in short-term contact with target vessels, and fluorescence could be detected ≥1 week after angioplasty. Consistently, local application of NFκB decoy oligodeoxynucleotides -loaded nanospheres resulted in significant inhibition of neointimal formation, associated with inhibition of NFκB binding activity in the injured arteries. The therapeutic effects were caused by inhibition of macrophage recruitment through the suppression of monocyte chemoattractant protein-1, vascular cell adhesion molecule-1, and CC chemokine ligand 4 expression and inhibition of vascular smooth muscle cell growth via a decrease in the expression of cyclin A and proliferating cell nuclear antigen. Importantly, application of NFκB nanospheres accelerated restoration of the endothelial cell monolayer, associated with enhanced expression of phosphorylated Bcl-2 in endothelial cells.

CONCLUSIONS

A drug-coated balloon catheter using NFκB decoy oligodeoxynucleotides significantly inhibited the development of neointimal hyperplasia in rabbits. The present study indicates the possibility of a novel therapeutic option to prevent restenosis after angioplasty.

Evaluation of long-term clinical and health service outcomes following coronary artery revascularisation in Western Australia (WACARP): a population-based cohort study protocol

INTRODUCTION

Coronary artery bypass grafting (CABG) and percutaneous coronary interventions (PCI) are procedures commonly performed on patients with significant obstructive coronary artery disease to relieve symptoms of ischaemia, improve survival or both. Although the efficacy of both procedures at the individual level has been established, the impact of advances in coronary artery revascularisation procedures (CARP) on long-term outcomes and cost-effectiveness at the population level are yet to be assessed. Our aim is to evaluate a minimum of 6-year outcomes and costs for the total population of patients who had CARP in Western Australia (WA) in 2000-2005.

METHODS AND ANALYSIS

This retrospective population cohort study will link clinical and administrative health data for a previously defined cohort including all patients in WA who had a CARP in the period 2000-2005. The cohort consists of 19,014 patients who had 21,175 procedures (15,429 PCI and 5746 CABG). We are now collecting a minimum of 6 years follow-up of morbidity and mortality data for the cohort using the WA Data Linkage System, clinical registries and hospital records, with 12 years follow-up for cases in the year 2000. Comparison of long-term outcomes for different CARP will be reported (PCI vs CABG; bare metal stents vs drug-eluting stents vs CABG). Cost-effectiveness analysis of CARP from the perspective of the healthcare sector will be performed using individual level cost data and average costs from Australian Refined Diagnosis Related Groups.

ETHICS AND DISSEMINATION

This study has received ethics approval from the University of Western Australia, the Western Australian Department of Health and all participating hospitals. Being a large population cohort study, approval included a waiver of informed consent. All findings will be presented at local, national and international healthcare/academic conferences and published in peer-reviewed journals.

Paclitaxel-coated balloon for the treatment of drug-eluting stent restenosis: subanalysis results from the Valentines I trial

OBJECTIVES

To analyze the effect of paclitaxel-coated balloon (PCB) treatment on patients with drug-eluting stent (DES) restenosis.

BACKGROUND

In the Valentines I trial, treatment of coronary in-stent restenosis was effective and safe with the second-generation DIOR® PCB.

METHODS

Valentines I prospectively enrolled 250 patients with in-stent restenosis (ISR); 76 patients (30.4%) had restenosis of a previous paclitaxel or limus DES. Patients underwent balloon angioplasty followed by PCB treatment. Clinical outcomes of patients with paclitaxel-eluting DES restenosis (n=34; 41 lesions) and limus-eluting (sirolimus, everolimus and zotarolimus) DES restenosis (n=42; 43 lesions) treated with DIOR® PCB were compared.

RESULTS

Baseline characteristics were similar. There were more diffuse lesions >20mm treated in paclitaxel- compared to limus-eluting DES restenosis (50% vs. 26.8%, p=0.032). Number of PCB used per patient (1.08±0.31 overall), mean PCB diameter (2.99±0.42mm overall), mean PCB length (24.4±11.9mm overall), and bailout stenting (2.4% vs. 4.7%) were similar (p=NS). At mean follow-up of 231±43days, major adverse cardiac events was 0% vs. 23.8% in paclitaxel- vs. limus-eluting DES restenosis (p=0.002), driven mainly by less target vessel revascularization (0% vs. 21.4%, p=0.004). Target lesion revascularization was 0% vs. 16.7% for paclitaxel- vs. limus-eluting DES restenosis (p=0.015).

CONCLUSION

In Valentines I, PCB use was more effective in patients with paclitaxel DES restenosis compared to limus DES restenosis, achieving better mid-term clinical outcomes. This suggests the efficacy of localized paclitaxel delivery to overcome paclitaxel resistance but not limus resistance due to different mechanisms of DES failure.

Inhibition of miR-92a improves re-endothelialization and prevents neointima formation following vascular injury

Aims

MicroRNA (miR)-92a is an important regulator of endothelial proliferation and angiogenesis after ischaemia, but the effects of miR-92a on re-endothelialization and neointimal lesion formation after vascular injury remain elusive. We tested the effects of lowering miR-92a levels using specific locked nucleic acid (LNA)-based antimiRs as well as endothelial-specific knock out of miR-92a on re-endothelialization and neointimal formation after wire-induced injury of the femoral artery in mice.

Methods and results

MiR-92a was significantly up-regulated in neointimal lesions following wire-induced injury. Pre-miR-92a overexpression resulted in repression of the direct miR-92a target genes integrin α5 and sirtuin1, and reduced eNOS expression in vitro. MiR-92a impaired proliferation and migration of endothelial cells but not smooth muscle cells. In vivo, systemic inhibition of miR-92a expression with LNA-modified antisense molecules resulted in a significant acceleration of re-endothelialization of the denuded vessel area. Genetic deletion of miR-92a in Tie2-expressing cells, representing mainly endothelial cells, enhanced re-endothelialization, whereas no phenotype was observed in mice lacking miR-92a expression in haematopoietic cells. The enhanced endothelial recovery was associated with reduced accumulation of leucocytes and inhibition of neointimal formation 21 days after injury and led to the de-repression of the miR-92a targets integrin α5 and sirtuin1.

Conclusion

Our data indicate that inhibition of endothelial miR-92a attenuates neointimal lesion formation by accelerating re-endothelialization and thus represents a putative novel mechanism to enhance the functional recovery following vascular injury.

Chronic treatment with trimetazidine after discharge reduces the incidence of restenosis in patients who received coronary stent implantation: a 1-year prospective follow-up study

BACKGROUND

The incidence of stent restenosis (SR) has risen with as more patients are being treated with drug-eluting stents (DESs). Trimetazidine has multiple favorable effects on the cardiovascular system. Here, we aimed to evaluate whether chronic treatment with trimetazidine reduced the incidence of SR.

METHODS

From January 2009 to December 2011 at Chinese PLA General Hospital, 768 patients were enrolled and randomized into the trimetazidine treatment group (TG, n = 384) and control group (CG, n = 384). After DES implantation, all patients were treated with regular medication. In the TG, trimetazidine was administrated at 20mg tid for at least 30days. All patients received follow-up angiography 9-13 months after discharge. Major adverse cardiac and cerebrovascular events (MACCEs) were recorded.

RESULTS

Six hundred thirty-five patients were included in the final analysis (TG, n = 312; CG, n = 323). SR occurred in 49 (7.7%) patients. The TG had a lower incidence of SR compared to the CG (4.2% vs. 11.1%, p = 0.001). At the 30-day follow-up, the TG exhibited a higher left ventricular ejection fraction than the CG (65.4 ± 10.7 vs. 63.1 ± 10.4, p = 0.006). The incidence of MACCEs was also lower in the TG at the 1-year follow-up (6.1% vs. 10.8%, p = 0.032). Further multivariate analysis revealed that trimetazidine treatment was a predictor for SR (OR: 0.376; 95% CI: 0.196-0.721; p = 0.003).

CONCLUSIONS

Trimetazidine treatment effectively reduced the incidence of SR and MACCEs after DES implantation at the 1-year follow-up.

Meta-analysis of same versus different stent for drug-eluting stent restenosis

Drug-eluting stent (DES) in-stent restenosis (ISR) can be treated by restenting using the same DES as previously placed (same stent strategy), versus switching to a stent that elutes a different drug (different stent strategy). To compare the efficacy of these strategies, a meta-analysis of controlled trials and observational studies evaluating patients with DES ISR was performed. The primary outcome was target lesion revascularization or target vessel revascularization, and secondary outcomes were major adverse cardiovascular events, death, and myocardial infarction. Pooled odds ratios (ORs) were calculated with the generic inverse variance method using a random-effects model. The chi-square test was used to evaluate heterogeneity. Ten studies (1,680 patients) were included. There was no significant heterogeneity among the studies for any end point. The different stent strategy was found to reduce the odds of target lesion revascularization or target vessel revascularization (OR 0.73, 95% confidence interval [CI] 0.55 to 0.96) and major adverse cardiovascular events (OR 0.72, 95% CI 0.54 to 0.96). There was no difference between the 2 strategies in rates of death (OR 1.03, 95% CI 0.49 to 2.16) or myocardial infarction (OR 0.59, 95% CI 0.24 to 1.41). In conclusion, this study demonstrates that treatment of DES ISR by restenting with a different DES than previously placed may lead to improved outcomes compared with the use of the same DES. Further large-scale trials are needed to confirm this effect.

Increased thin-cap neoatheroma and periprocedural myocardial infarction in drug-eluting stent restenosis: multimodality intravascular imaging of drug-eluting and bare-metal stents

BACKGROUND

Re-endothelialization is delayed after drug-eluting stent (DES) implantation. In this setting, neointima is more prone to become lipid laden and develop neoatherosclerosis (NA), potentially increasing plaque vulnerability.

METHODS AND RESULTS

Optical coherence tomography and near-infrared spectroscopy with intravascular ultrasound were used to characterize NA in 65 (51 DES and 14 bare-metal stents) consecutive symptomatic patients with in-stent restenosis. Median duration poststent implantation was 33 months. Optical coherence tomography-verified NA was observed in 40 stents with in-stent restenosis (62%), was more prevalent in DES than bare-metal stents (68% versus 36%; P=0.02), and demonstrated significantly higher prevalence of thin-cap neoatheroma (47% versus 7%; P=0.01) in DES. Near-infrared spectroscopy assessment demonstrated that the total lipid core burden index (34 [interquartile range, 12-92] versus 9 [interquartile range, 0-32]; P<0.001) and the density of lipid core burden index (lipid core burden index/4 mm, 144 [interquartile range, 60-285] versus 26 [interquartile range, 0-86]; P<0.001) were higher in DES compared with bare-metal stents. Topographically, NA was classified as I (thin-cap NA), II (thick-cap NA), and III (peri-strut NA). Type I thin-cap neoatheroma was more common in DES (20% versus 3%; P=0.01) and in areas of the stented segment without significant in-stent restenosis (71%). Periprocedural myocardial infarction occurred only in DES (11 versus 0; P=0.05), of which 6 (55%) could be attributed to segments with >70% in-stent restenosis. By logistic regression, prior DES was the only independent predictor of both NA (odds ratio, 7.0; 95% confidence interval, 1.7-27; P=0.006) and periprocedural myocardial infarction (odds ratio, 1.8; 95% confidence interval, 1.1-2.4; P=0.05).

CONCLUSIONS

In-stent thin-cap neoatheroma is more prevalent, is distributed more diffusely across the stented segment, and is associated with increased periprocedural myocardial infarction in DES compared with bare-metal stents. These findings support NA as a mechanism for late DES failure.

Optimal strategy of coronary revascularization in chronic kidney disease patients: a meta-analysis

BACKGROUND

Patients with chronic kidney disease (CKD) have high risks of coronary artery disease (CAD). Coronary revascularization is beneficial for long-term survival, but the optimal strategy remains still controversial.

METHODS

We searched studies that have compared percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) for revascularization of the coronary arteries in CKD patients. Short-term (30 days or in-hospital) mortality, long-term (at least 12 months) all-cause mortality, cardiac mortality and the incidence of late myocardial infarction and recurrence of revascularization were estimated.

RESULTS

28 studies with 38,740 patients were included. All were retrospective studies from 1977 to 2012. Meta-analysis showed that PCI group had lower short-term mortality (OR 0.55, 95% CI 0.41 to 0.73, P<0.01), but had higher long-term all-cause mortality (OR 1.29, 95% CI 1.23 to 1.35, P<0.01). Higher cardiac mortality (OR 1.08, 95% CI 1.01 to 1.15, P<0.05), higher incidence of late myocardial infarction (OR 1.78, 95% CI 1.65 to 1.91, P<0.01) and recurring revascularization rate (OR 2.94, 95%CI 2.15 to 4.01, P<0.01) is found amongst PCI treated patients compared to CABG group.

CONCLUSIONS

CKD patients with CAD received CABG had higher risk of short-term mortality but lower risks of long-term all-cause mortality, cardiac mortality and late myocardial infarction compared to PCI. This could be due to less probable repeated revascularization.

Study design elements for rigorous quasi-experimental comparative effectiveness research

Quasi-experiments are likely to be the workhorse study design used to generate evidence about the comparative effectiveness of alternative treatments, because of their feasibility, timeliness, affordability and external validity compared with randomized trials. In this review, we outline potential sources of discordance in results between quasi-experiments and experiments, review study design choices that can improve the internal validity of quasi-experiments, and outline innovative data linkage strategies that may be particularly useful in quasi-experimental comparative effectiveness research. There is an urgent need to resolve the debate about the evidentiary value of quasi-experiments since equal consideration of rigorous quasi-experiments will broaden the base of evidence that can be brought to bear in clinical decision-making and governmental policy-making.

Benefit of long-term dual anti-platelet therapy in patients treated with drug-eluting stents: from the NHLBI dynamic registry

The optimal duration of dual-antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation is an important, unanswered question. This study was designed to evaluate the association of varying durations of DAPT on clinical outcomes after DES implantation for the treatment of coronary artery disease. Using the National Heart, Lung, and Blood Institute Dynamic Registry, patients enrolled in the last 2 waves after index percutaneous coronary intervention with DES and who were event free at the time of landmark analysis were included. Landmark analysis was performed 12 and 24 months after percutaneous coronary intervention, and patients were stratified according to continued use of DAPT or not. Subjects were evaluated for rates of death, myocardial infarction, and stent thrombosis at 4 years from their index procedures. The numbers of evaluable patients were 2,157 and 1,918 for the 12- and 24-month landmarks, respectively. In both landmark analyses, there was a significantly lower 4-year rate of death or myocardial infarction in the group that continued DAPT compared to the group that did not (12 months: 10.5% vs 14.5%, p = 0.01; 24 months: 5.7% vs 8.6%, p = 0.02). Beneficial differences in the group that continued on DAPT were preserved after multivariate and propensity adjustment. There were no significant differences in definite stent thrombosis in either landmark analysis. In conclusion, at 12 and 24 months after DES implantation, continued use of DAPT was associated with lower 4-year risk for death and myocardial infarction.

The favorable price evolution between bare metal stents and drug eluting stents increases the cost effectiveness of drug eluting stents

AIMS

We aimed to assess the cost effectiveness of the sirolimus-eluting stent (SES) in diabetic and non-diabetic patients vs. bare metal stents (BMS).

METHODS

EVASTENT was a matched cohort registry of patients undergoing revascularization exclusively with SES; for each diabetic patient (db+) included, stratified according to single (SVD) or multiple (MVD) vessel disease, a non-diabetic patient (db-) was subsequently included. Efficacy, safety and cost data were obtained from the SES database, and then data from the BMS group were derived by using an original method of transition probabilities of events (Markov model and Monte Carlo simulations) if BMS had been implanted in the same patient, over a 3-year time period. Sensitivity analysis was performed by varying the price difference between BMS and SES from 2008 to 2012.

RESULTS

In this study, 1731 patients were included with 97% complete follow-up at 3-years. In 2008, compared to BMS the SES was cost effective only in MVD db+ (7494€ per avoided revascularization (PAR) vs. >10,000€ in other groups). In 2012, after a reduction in the price difference between SES and BMS, SES were cost effective in MVD db+ (-891), SVD db+ (3519), MVD db- (3050), and SVD db- (6329) patients. Otherwise, the cardiovascular mortality rate was higher (p<0.0001) in MVD db+ than in SVD db+, MVD db- and SVD db-.

CONCLUSION

The SES is now cost effective in diabetic and non-diabetic patients, after a favorable price evolution between drug eluting and bare metal stents.

Use and misuse of multivariable approaches in interventional cardiology studies on drug-eluting stents: a systematic review

AIMS

 Randomized clinical trials (RCTs) are the most reliable evidence, even if they require important resource and logistic efforts. Large, cost-free and real-world datasets may be easily accessed yielding to observational studies, but such analyses often lead to problematic results in the absence of careful methods, especially from a statistic point of view. We aimed to appraise the performance of current multivariable approaches in the estimation of causal treatment and effects in studies focusing on drug-eluting stents (DES).

METHODS AND RESULTS

Pertinent studies published in the literature were searched, selected, abstracted, and appraised for quality and validity features. Six studies with a logistic regression were included, all of them reporting more than 10 events for covariates and different length of follow-up, with an overall low risk of bias. Most of the 15 studies with a Cox proportional hazard analysis had a different follow-up, with less than 10 events for covariates, yielding an overall low or moderate risk of bias. Sixteen studies with propensity score were included: the most frequent method for variable selection was logistic regression, with underlying differences in follow-up and less than 10 events for covariate in most of them. Most frequently, calibration appraisal was not reported in the studies, on the contrary of discrimination appraisal, which was more frequently performed. In seventeen studies with propensity and matching, the latter was most commonly performed with a nearest neighbor-matching algorithm yet without appraisal in most of the studies of calibration or discrimination. Balance was evaluated in 46% of the studies, being obtained for all variables in 48% of them.

CONCLUSIONS

 Better exploitation and methodological appraisal of multivariable analysis is needed to improve the clinical and research impact and reliability of nonrandomized studies.

Controversies in the use & implementation of drug-eluting stent technology

The introduction of drug eluting stents has resulted in dramatic reductions in the rates of restenosis and the need for repeat revascularization. In the last several years, concern has been raised regarding the long-term safety of this technology, particularly in the area of late restenosis and stent thrombosis. The development of newer anti-restenotic drug coatings, biodegradable polymers and even completely bioabsorbable stents offer the potential to address these limitations. Additional questions that have recently come to the forefront include the optimal duration of dual antiplatelet therapy, the use of platelet reactivity assays and genetic testing and drug eluting stent use in the treatment of acute myocardial infarction. This article will attempt to address these and other areas of controversy in the use and implementation of drug eluting stents.