Drug eluting stents: an updated meta-analysis of randomised controlled trials

Infarct-related artery only revascularization versus multi-vessel revascularization for patients with Killip I-IV acute myocardial infarction and multivessel disease

BACKGROUND

The optimal revascularization strategy for non-culprit vessels is still up for debate nowadays, particularly when it comes to individuals with different Killip classes. Therefore, the aim of our study was to investigate whether multivessel revascularization, as compared with infarct-related artery (IRA) alone revascularization, improves long-term prognosis in patients who have experienced an acute myocardial infarction (AMI) and have multivessel coronary artery disease (CAD).

METHODS

A retrospective analysis was conducted on clinical data from 646 patients who presented with AMI and multivessel CAD at Beijing Chaoyang hospital between November 2014 and November 2020. Based on various revascularization strategies, patients were categorised into two groups: IRA-only revascularization (n = 416) and multivessel revascularization (n = 230). The primary endpoint was cardiovascular death.

RESULTS

In the following 60.6 months (60.6 ± 23.9), the primary endpoint occurred in 3% of the multivessel revascularization group versus 9.6% in the IRA-only revascularization group (HR 0.284, CI 0.120-0.669, p = 0.002). For the Killip I-II patients (n = 533), the primary endpoint occurred in 2.6% of the multivessel revascularization group versus 9.5% in the IRA-only revascularization group (HR 0.236, CI 0.083-0.667, p = 0.003). For Killip III-IV patients (n = 113), there was no significance differences in the primary endpoint. After using the inverse probability weighted method, the benefit of complete revascularization was consistently observed.

CONCLUSIONS

Multivessel revascularization significantly reduced the incidence of cardiovascular death for patients presenting with AMI and multivessel CAD, particularly for Killip I-II patients. There were no significant differences in the primary outcome across the groups of patients with Killip III-IV.

Coronary CT-based FFR in patients with acute myocardial infarction might predict follow-up invasive FFR: The XPECT-MI study

BACKGROUND

We aimed to evaluate whether invasive fractional flow reserve (FFRi) of non-infarction related (non-IRA) lesions changes over time in ST-elevation myocardial infarction (STEMI) patients. Moreover, we assessed the diagnostic performance of coronary CT angiography-derived FFR(FFRCT) following the index event in predicting follow-up FFRi.

METHODS

We prospectively enrolled 38 STEMI patients (mean age 61.6 ​± ​9 years, 23.1% female) who underwent non-IRA baseline and follow-up FFRi measurements and a baseline FFRCT (within ≤10 days after STEMI). Follow-up FFRi was performed at 45-60 days (FFRi and FFRCT value of ≤0.8 was considered positive).

RESULTS

FFRi values showed significant difference between baseline and follow-up (median and interquartile range (IQR) 0.85 [0.78-0.92] vs. 0.81 [0.73-0.90] p ​= ​0.04, respectively). Median FFRCT was 0.81 [0.68-0.93]. In total, 20 lesions were positive on FFRCT. A stronger correlation and smaller bias were found between FFRCT and follow-up FFRi (ρ ​= ​0.86,p ​< ​0.001,bias:0.01) as compared with baseline FFRi (ρ ​= ​0.68, p ​< ​0.001,bias:0.04). Comparing follow-up FFRi and FFRCT, no false negatives but two false positive cases were found. The overall accuracy was 94.7%, with sensitivity and specificity of 100.0% and 90.0% for identifying lesions ≤0.8 on FFRi. Accuracy, sensitivity, and specificity were 81.5%, 93.3%, and 73.9%, respectively, for identifying significant lesions on baseline FFRi using index FFRCT.

CONCLUSION

FFRCT in STEMI patients close to the index event could identify hemodynamically relevant non-IRA lesions with higher accuracy than FFRi measured at the index PCI, using follow-up FFRi as the reference standard. Early FFRCT in STEMI patients might represent a new application for cardiac CT to improve the identification of patients who benefit most from staged non-IRA revascularization.

Long-term Outcomes for Drug-eluting Balloons versus Drug-eluting Stents in the Treatment of Small Vessel Coronary Artery Disease: A Systematic Review and Meta-analysis

Background: This systematic review and meta-analysis compares long-term outcomes follow-up data comparing drug-eluting balloons (DEBs) and drug-eluting stents (DESs) in interventional treatment of small coronary artery disease (<3 mm). Methods: A systematic review was undertaken along with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The primary outcome was 1-3-year performance of DEB versus DES in major adverse cardiac events. Secondary outcomes include all-cause mortality, MI, cardiac death, vessel thrombosis, major bleeding, target vessel revascularisation and target lesion revascularisation. Two independent reviewers extracted data. All outcomes used the Mantel-Haenszel and random effects models. ORs are presented with a 95% CI. Results: Of 4,661 articles, four randomised control trials were included (1,414 patients). DEBs demonstrated reduced rates of non-fatal MI at 1 year (OR 0.44; 95% CI [0.2-0.94]), and BASKET-SMALL 2 reported a significant reduction in 2-year bleeding rates (OR 0.3; 95% CI [0.1-0.91]). There was no significant difference in all other outcomes. Conclusion: Long-term follow-up of DEB and DES use in small coronary arteries demonstrates DEBs be comparable with DESs in all outcomes at 1, 2 and 3 years of follow-up. A significant reduction was found in rates of non-fatal MI at 1 year in the DEB arm, and a reduction in major bleeding episodes at 2 years in the BASKET-SMALL 2 trial. These data highlight the potential long-term utility of novel DEBs in small coronary artery disease revascularisation.

Bivalirudin and sirolimus co-eluting coronary stent: Potential strategy for the prevention of stent thrombosis and restenosis

Localized drug delivery with sustained elution characteristics from nanocarrier coated stents represents a viable therapeutic approach to circumvent concerns related to coronary stent therapy. We fabricated a Sirolimus (SRL) and Bivalirudin (BIV) releasing nanoparticles (NPs) coated stent for concurrent mitigation of vascular restenosis and acute stent thrombosis. SRL NPs were prepared by nanoprecipitation method whereas the BIV vesicles were generated using hydrophobic ion pair approach followed by micellization phenomenon. MTT assay and confocal microscopic analysis indicated superior anti-proliferative activity and higher cellular uptake of SRL NPs into human coronary artery smooth muscle cells, respectively. DSC and ATR-FTIR techniques confirmed the formation of complex between BIV and phosphatidylglycerol via some weak physical interactions. More than 2 fold rise in log P value was obtained for DSPG-BIV at 3:1 M ratio compared with native BIV solution. The SAXS analysis indicated formation of oligolamellar vesicles of DSPG-BIV complex which was preferentially entrapped into lipophilic lamellae of vesicles. APTT, PT, and TT tests revealed that the BIV vesicles caused significant prolongation of clotting time compared to native BIV solution. The SEM analysis showed uniform and defect free stent coating. In vitro release study demonstrated that SRL and BIV were eluted in a sustained manner from coated stents.

Toward Brief Dual Antiplatelet Therapy and P2Y12 Inhibitors for Monotherapy After PCI

The optimal duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention remains a controversial topic. The European Society of Cardiology and the American College of Cardiology/American Heart Association recommend at least 6 and 12 months of DAPT after PCI in patients with stable coronary artery disease or acute coronary syndrome, respectively. Although prolonging DAPT duration reduces ischemic events, it is associated with higher rates of bleeding and possible fatal outcomes. The DAPT score can be an important tool to identify patients who may still benefit from prolonged therapy. Nevertheless, several recent randomized controlled trials showed that shortening DAPT duration from 12 to 1-3 months reduces bleeding rates without significantly increasing ischemic event rates. These trials also suggested replacing acetylsalicylic acid (aspirin) with P2Y12 inhibitors after short-term DAPT. We review and compare past and present studies regarding DAPT and analyze the evidence favoring a short DAPT duration and the long-term single antiplatelet agent of choice.

The long-term impact of a chronic total occlusion in a non-infarct-related artery on acute ST-segment elevation myocardial infarction after primary coronary intervention

OBJECTIVES

To investigate the long-term outcome of patients with acute ST-segment elevation myocardial infarction (STEMI) and a chronic total occlusion (CTO) in a non-infarct-related artery (IRA) and the risk factors for mortality.

METHODS

The enrolled cohort comprised 323 patients with STEMI and multivessel diseases (MVD) that received a primary percutaneous coronary intervention between January 2008 and November 2013. The patients were divided into two groups: the CTO group (n = 97) and the non-CTO group (n = 236). The long-term major adverse cardiovascular and cerebrovascular events (MACCE) experienced by each group were compared.

RESULTS

The rates of all-cause mortality and MACCE were significantly higher in the CTO group than they were in the non-CTO group. Cox regression analysis showed that an age ≥ 65 years (OR = 3.94, 95% CI: 1.47-10.56, P = 0.01), a CTO in a non-IRA(OR = 5.09, 95% CI: 1.79 ~ 14.54, P < 0.01), an in-hospital Killip class ≥ 3 (OR = 4.32, 95% CI: 1.71 ~ 10.95, P < 0.01), and the presence of renal insufficiency (OR = 5.32, 95% CI: 1.49 ~ 19.01, P = 0.01), stress ulcer with gastraintestinal bleeding (SUB) (OR = 6.36, 95% CI: (1.45 ~ 28.01, P = 0.01) were significantly related the 10-year mortality of patients with STEMI and MVD; an in-hospital Killip class ≥ 3 (OR = 2.97,95% CI:1.46 ~ 6.03, P < 0.01) and the presence of renal insufficiency (OR = 5.61, 95% CI: 1.19 ~ 26.39, P = 0.03) were significantly related to the 10-year mortality of patients with STEMI and a CTO.

CONCLUSIONS

The presence of a CTO in a non-IRA, an age ≥ 65 years, an in-hospital Killip class ≥ 3, and the presence of renal insufficiency, and SUB were independent risk predictors for the long-term mortality of patients with STEMI and MVD; an in-hospital Killip class ≥ 3 and renal insufficiency were independent risk predictors for the long-term mortality of patients with STEMI and a CTO.

An Update on Drug-eluting Technology in Peripheral Arteries to Treat Peripheral Arterial Disease

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A potential role for the CDH13/CDH15 gene in repeat revascularization after first percutaneous coronary intervention

Aim: Major drawbacks of percutaneous coronary intervention are the high occurrence of repeat revascularization due to restenosis and disease progression. The aim of this study was to find genetic indicators to predict the risk of repeat revascularization. Materials & methods: From April 2015 to June 2016, 143 patients with percutaneous coronary intervention with genetic test results were enrolled. SNPs were measured by OmniZhongHua-8, and the SNPs in pathways genes related to known stenosis-related processes from the KEGG, BioCarta and Gene Cards databases were selected for analysis. Results: Cell-extracellular matrix interactions were the pathways with the most significant SNP (CDH15 rs72819363) association with repeat revascularization. Compared with CDH13 rs11859453G carriers, the adjusted odds ratio for A carriers was 0.25 and 0.33 at 18 and 30 months. Conclusion: We demonstrated a potential role of the cell-extracellular matrix interactions pathway and the possible biomarker CDH13/CDH15 in the development of coronary repeat revascularization.

High red blood cell distribution width is closely associated with in-stent restenosis in patients with unstable angina pectoris

Background

In-stent restenosis remains an unresolved issue. Inflammation plays a pivotal role in the process of in-stent restenosis. Significant and positive associations were found between red blood cell distribution width (RDW) and inflammation. But whether there is a close relationship between higher RDW and in-stent restenosis is still not clarified.

Methods

This retrospective observational study investigated 214 consecutive patients with unstable angina pectoris who underwent successful percutaneous coronary interventions with drug-eluting stents. Patients were divided into three groups according to baseline RDW before percutaneous coronary interventions (low RDW group:≤12.5%; intermediate RDW group:> 12.5% and ≤ 13.5%; high RDW group:> 13.5%). The follow-up angiographies were routinely performed 9–12 months after the initial percutaneous coronary interventions. The multivariate logistic regression analysis was employed to determine the independent predictors of in-stent restenosis.

Results

The in-stent restenosis rate was significantly higher in group with higher baseline RDW value (12.3, 19.7, 47.7% in low, intermediate, and high RDW groups respectively, P < 0.001). The baseline RDWs were significantly higher in patients with in-stent restenosis compared with those in patients without in-stent restenosis (13.7 ± 0.8% vs. 13.0 ± 0.8%, P < 0.001). For prediction of in-stent restenosis, the ROC (receiver operating characteristic) curve analysis demonstrated the optimal RDW cutoff value was 13.37 (sensitivity: 65.5%, specificity: 73.6%); the diagnosis cutoff value was 13.89 (sensitivity: 40.0%, specificity: 91.8%); the screening cutoff value was 12.99 (sensitivity: 83.6%, specificity: 49.1%). By multivariate logistic analysis, higher baseline RDW (odds ratio [OR], 5.179; 95% confidence interval [CI], 2.568 to 10.446; P<0.001) together with lower baseline indirect bilirubin (OR, 0.413; 95% CI, 0.305 to 0.559; P<0.001) and diabetes (OR, 4.077; 95% CI, 1.654 to 10.054; P = 0.002) were closely associated with in-stent restenosis at followup (11.1 ± 5.8 months).

Conclusions

The baseline RDW was closely associated with in-stent restenosis at follow-up. The patients with higher baseline RDW might have more chances to develop in-stent restenosis at followup.

Association study of matrix metalloproteinase 3 5A/6A polymorphism with in-stent restenosis after percutaneous coronary interventions in a Han Chinese population

Objective

We aimed to investigate the association between the 5A/6A promoter polymorphism in the matrix metalloproteinase 3 (MMP3) gene and in-stent restenosis (ISR) in a regional Chinese population.

Methods

A total of 818 patients who underwent primary implantation of drug-eluting stents were enrolled and received a 6-month follow-up angiography and DNA genotyping of the 5A/6A polymorphism.

Results

ISR was found in 36.9% of all patients (302 ISR vs. 516 no ISR). The genotype proportion of 6A6A was significantly increased in ISRs (74.2% ISR vs. 66.8% no ISR), whereas the allele frequency of 5A was significantly decreased in ISR patients (25.8%) compared with controls who did not undergo ISR (33.1%).

Conclusions

Our data indicate that the MMP3 6A6A genotype is a genetic susceptibility factor for ISR after coronary stent placement, but the 5A allele can lower the risk for patients within 6 months after stenting. Therefore, genotyping 5A/6A in the MMP3 promoter is suggested for patients who undergo coronary stent implantation.

HIV status and type of coronary stent placed in patients presenting with ST-elevation myocardial infarction

BACKGROUND

Drug-eluting stents (DES) outperform bare-metal stents (BMS) in reducing target vessel revascularization following a percutaneous coronary intervention (PCI). Little is known about the types of stents placed in HIV-positive patients presenting with ST-segment elevation myocardial infarctions (STEMIs).

METHODS

We used the 2003-2013 National Inpatient Sample to identify adults of 18 years or older presenting with STEMI. We evaluated differences in stent type placed following STEMIs on the basis of HIV status. Temporal trends in the use of PCI, DES, and BMS were studied on the basis of HIV status.

RESULTS

Of 1 695 947 patients with STEMI, 5887 (0.3%) were HIV-positive patients. Following STEMIs, HIV-positive patients were equally likely to have PCI compared with HIV-negative patients [adjusted odds ratio (AOR): 1.04, 95% confidence interval (CI): 0.89-1.21, P=0.63]. However, HIV-positive patients were less likely to have DES (AOR: 0.83, 95% CI: 0.73-0.94, P=0.003) and more likely to have BMS (AOR: 1.26, 95% CI: 1.11-1.45, P=0.001). Over the 11-year period observed, there were increases in PCI following STEMIs in both HIV-positive and HIV-negative patients (all Ptrend<0.001). There were significant increases in the use of DES in HIV-negative patients [adjusted odds ratio (AOR) per year: 1.07, 95% CI: 1.06-1.09, Ptrend<0.001] and significant decreases in the use of BMS (AOR per year: 0.93, 95% CI: 0.92-0.94, Ptrend<0.001). Significant trends showing changed practice patterns in the use of DES and BMS among HIV-positive patients were not observed.

CONCLUSION

Over a decade, there were significant increases in the use of PCI following STEMIs in both HIV-negative and HIV-positive patients. Although HIV-positive patients presenting with STEMIs were as likely as HIV-negative patients to undergo PCI, they were less likely to be treated with DES and more likely to receive BMS. Highlighting these observations will hopefully bring renewed attention to best practices for all STEMI patients.

Different Effects of Thiazolidinediones on In-Stent Restenosis and Target Lesion Revascularization after PCI: A Meta-Analysis of Randomized Controlled Trials

In-stent restenosis (ISR) remains the leading problem encountered after percutaneous coronary intervention (PCI). Thiazolidinediones (TZDs) has been shown to be associated with reduced ISR and target lesion revascularization (TLR); however, the results are inconsistent, especially between rosiglitazone and pioglitazone. In this study, fourteen RCTs with a total of 1350 patients were finally included through a systematical literature search of Embase, Pubmed, the Cochrane Library, and ClinicalTrials.gov from inception to January 31, 2017. The follow-up duration of the included trials ranged from 6 months to 18 months. The results demonstrated that TZDs treatment is associated with significantly reduced risk of TLR (RR:0.45, 95%CI 0.30 to 0.67 for pioglitazone, RR:0.68, 95%CI 0.46 to 1.00 for rosiglitazone). Pioglitazone is associated with significantly reduced risks of ISR (RR:0.47, 95%CI 0.27 to 0.81), major adverse cardiac events (MACE) (RR:0.44, 95%CI 0.30 to 0.64) and neointimal area (SMD: −0.585, 95%CI −0.910 to −0.261). No significant relationship was observed between rosiglitazone and ISR (RR:0.91, 95%CI 0.39 to 2.12), MACE (RR:0.73, 95%CI 0.53 to 1.00) and neointimal area (SMD: −0.164, 95%CI −1.146 to 0.818). This meta-analysis demonstrated that TZDs treatment is associated with significant reduction in ISR, TLR and MACE for patients after PCI. Pioglitazone treatment seems to have more beneficial effects than rosiglitazone and no significantly increased cardiovascular risk was detected for both agents.

Temporal trends in percutaneous coronary interventions thru the drug eluting stent era: Insights from 18,641 procedures performed over 12-year period

BACKGROUND

The last decade, regarded as the DES era in PCI, has witnessed significant advances in the management of coronary disease. We aimed to assess temporal trends in the practice and outcome of percutaneous coronary intervention (PCI) during the drug eluting stent (DES) era.

METHODS

We analyzed 18,641 consecutive PCI's performed between January 2004 and December 2016, distinguished by procedural date (Q₁ : 2004-2006, n = 4,865; Q₂ : 2007-2009, n = 4,977; Q₃ : 2010-2012, n = 4,230; Q₄ : 2013-2016, n = 4,569).

RESULTS

At presentation, mean patients age was 65 (±11) years and 22.8% were females. Over time, there was a rise in the relative number of octogenarians (Q₁ : 10.7% vs Q₄ : 15.5%, P < 0.001) and an increase in the burden of most comorbidities (e.g., left ventricular dysfunction ≥ moderate and chronic kidney disease, P < 0.001 for both). Despite a 2-fold increase in the rate of complex interventions, and a 3-fold increase in the rate of unprotected left-main angioplasty (P < 0.001 for both), the radial approach was increasingly adopted (Q₁ : 2% to Q₄ : 63.5%, P < 0.001). DES implantation increased from 43% to 83% at the expense of bare metal stent (BMS) application, and accompanied by drug coated balloon sprout to 1.8%, P < 0.001. Kaplan-Meier survival curves revealed a time-based enhanced outcome, with a decreased rate of death, MI, target vessel revascularization and CABG over the years.

CONCLUSIONS

In the last decade, PCI has evolved to offer better outcome to more elderly, sicker patient population, with more complex coronary disease interventions. The shift to second generation DES and to enhanced PCI techniques may explain part of this progress.

Clinical, humanistic, and economic outcomes between drug-eluting stent (DES) and bare metal stent (BMS): 18-month follow-up study

BACKGROUND

Percutaneous coronary intervention (PCI) is one of the most performed interventions for ischemic heart diseases. In Hong Kong, the total number of patient discharges and deaths for ischemic heart diseases in 2009 was 33,363, including 4,360 deaths. There are over 5,000 cases of PCI yearly. This study aimed to compare clinical, economic, and humanistic outcomes among patients receiving drug-eluting stent (DES) or bare metal stent (BMS) in Hong Kong.

METHODS

Patients who received stent implantation between September 15, 2009 and October 11, 2010 in Prince of Wales Hospital, Hong Kong, were recruited and followed for 18 months. Occurrence of major adverse cardiac events (cardiac death, non-fatal MI, TLR and TVR) was employed as the clinical outcome measurements. Improvement in quality-of-life by stent interventions was measured as quality-adjusted life-year (QALY). EQ-5D questionnaire was adopted to assess the QALY gained. Cost-utility analysis and cost-effectiveness analysis for BMS and DES were employed as the economic outcome measurement.

RESULTS

Six hundred and eighty-four patients (DES = 402; BMS = 282) were included. From 0-18 months, TLR rate (2.7% vs 3.5%, p = .549) and TVR rate (3.7% vs 6.4%, p = .111) were lower in the DES group, but without statistical significance. EQ VAS (71.06 ± 14.56 vs 71.07 ± 16.57, p = .998) and utility score (0.81 ± 0.17 vs 0.78 ± 0.16, p = .162) were comparable between DES and BMS group. Overall, the cost per QALY gained was HKD + 1,178,100 and ICER was HKD + 187,000 (1USD = 7.8 HKD).

CONCLUSIONS

No significant difference in TVR, TLR rates, EQ VAS, and utility score was found between the DES and BMS group. The higher cost of index procedure for the DES group was found to be partly offset by reduced cost of follow-up, offering cost-effectiveness in ACS patients, predominantly in STEMI patients. DES was recommended for STEMI patients.

Effect of Pioglitazone in Preventing In-Stent Restenosis after Percutaneous Coronary Intervention in Patients with Type 2 Diabetes: A Meta-Analysis

BACKGROUND

The benefits of pioglitazone in patients with type 2 diabetes mellitus (T2DM) after percutaneous coronary intervention (PCI) is unclear.

OBJECTIVES

To evaluate the effect of pioglitazone on prevention of in-stent restenosis (ISR) in patients with T2DM after PCI.

METHODS

All full-text published relevant studies compared the effect of pioglitazone with control group (placebo or no pioglitazone treatment) on ISR in patients with T2DM after PCI were identified by searching the databases including PubMed, EMBASE, Cochrane Library and ISI Web of Science through October 2015. The endpoints were defined as the rate of ISR, late lumen loss, in-stent neointimal volume, target lesion revascularization (TLR) and major adverse cardiac events (MACE).

RESULTS

Six studies (5 RCTs and 1 retrospective study), comprising 503 patients, were included into this meta-analysis. In the pioglitazone group, as compared with the control group, the risk ratio for ISR was 0.48 (I2 = 14.5%, P = 0.322; 95%CI 0.35 to 0.68, P<0.001), the risk ratio for TLR was 0.58 (I2 = 6.0%, P = 0.363; 95%CI 0.38 to 0.87, P = 0.009). The result showed there was no association between the use of pioglitazone and the events of MACE (I2 = 36.7%, P = 0.209; RR 0.56, 95%CI 0.30 to 1.05, P = 0.071). For the considerable heterogeneity, further analysis was not suitable for the endpoints of late lumen loss (I2 = 81.9%, P<0.001) and neointimal volume (I2 = 75.9%, P = 0.016).

CONCLUSIONS

The treatment of pioglitazone was associated with a reduction in ISR and TLR in T2DM patients suffering from PCI, except the incidence of MACE.

The effects of plasma electrolytically oxidized NiTi on in vitro endothelialization

The role of biomaterials surface in controlling the interfacial biological events leading to implant integration is of key importance. In this study, the effects of NiTi surfaces treated by plasma electrolytic oxidation (PEO) on human umbilical vein endothelial cells (HUVECs) have been investigated. The changes in NiTi surface morphology and chemistry were assessed by SEM, XPS and cross-section TEM/EDX analyzes whereas the effects of the resultant surfaces on in vitro endothelialization and cell junction proteins have been evaluated by life/dead staining, SEM, cells counting, qPCR and immunofluorescence. The findings indicated that the PEO-treated NiTi, with a microporous morphology and oxide dominated surface chemistry, supports viability and proliferation of HUVECs. Numerous thin filopodia probing the microporous surface assisted cells attachment. In addition, claudin-5 and occludin have been upregulated and expression of vascular endothelial-cadherin was not suppressed on PEO-treated NiTi relative to the reference electropolished surfaces. The results of this study suggest that novel NiTi surfaces may be developed using the PEO process, which can be of benefit to atherosclerosis treatment.

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.

The Many Faces of the A2b Adenosine Receptor in Cardiovascular and Metabolic Diseases

Modulation of the low affinity adenosine receptor subtype, the A2b adenosine receptor (A2bAR), has gained interest as a therapeutic target in various pathologic areas associated with cardiovascular disease. The actions of the A2bAR are diverse and at times conflicting depending on cell and tissue type and the timing of activation or inhibition of the receptor. The A2bAR is a promising and exciting pharmacologic target, however, a thorough understanding of A2bAR action is necessary to reach the therapeutic potential of this receptor. This review will focus on the role of the A2bAR in various cardiovascular and metabolic pathologies in which the receptor is currently being studied. We will illustrate the complexities of A2bAR signaling and highlight areas of research with potential for therapeutic development.

Coating Techniques and Release Kinetics of Drug-Eluting Stents

Implantation of drug-eluting stents (DESs) via percutaneous coronary intervention is the most popular treatment option to restore blood flow to occluded vasculature. The many devices currently used in clinic and under examination in research laboratories are manufactured using a variety of coating techniques to create the incorporated drug release platforms. These coating techniques offer various benefits including ease of use, expense of equipment, and design variability. This review paper discusses recent novel DES designs utilizing individual or a combination of these coating techniques and their resulting drug release profiles.

Comparison of long-term safety and efficacy outcomes after drug-eluting and bare-metal stent use across racial groups: Insights from NHLBI Dynamic Registry

BACKGROUND

Long-term data on outcomes after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) and bare-metal stent (BMS) across racial groups are limited, and minorities are under-represented in existing clinical trials. Whether DES has better long-term clinical outcomes compared to BMS across racial groups remains to be established. Accordingly, we assessed whether longer-term clinical outcomes are better with DES compared to BMS across racial groups.

METHODS

Using the multicenter National Heart, Lung, and Blood Institute (NHLBI)-sponsored Dynamic Registry, 2-year safety (death, MI) and efficacy (repeat revascularization) outcomes of 3326 patients who underwent PCI with DES versus BMS were evaluated.

RESULTS

With propensity-score adjusted analysis, the use of DES, compared to BMS, was associated with a lower risk for death or MI at 2 years for both blacks (adjusted Hazard Ratio (aHR)=0.41, 95% CI 0.25-0.69, p<0.001) and whites (aHR=0.67, 95% CI 0.51-0.90, p=0.007). DES use was associated with a significant 24% lower risk of repeat revascularization in whites (aHR=0.76, 95% CI 0.60-0.97, p=0.03) and with nominal 34% lower risk in blacks (aHR=0.66, 95% CI 0.39-1.13, p=0.13).

CONCLUSION

The use of DES in PCI was associated with better long-term safety outcomes across racial groups. Compared to BMS, DES was more effective in reducing repeat revascularization in whites and blacks, but this benefit was attenuated after statistical adjustment in blacks. These findings indicate that DES is superior to BMS in all patients regardless of race. Further studies are needed to determine long-term outcomes across racial groups with newer generation stents.

Effect of pioglitazone on in-stent restenosis after coronary drug-eluting stent implantation: a meta-analysis of randomized controlled trials

BACKGROUND

In-stent restenosis (ISR) remains a common life-threatening complication and some studies have shown that pioglitazone can reduce the incidence of ISR in patients with drug-eluting stents (DES) implantation. We conducted a meta-analysis to assess the effect of pioglitazone in preventing ISR after DES implantation.

METHODS

Randomized controlled trials (RCTs) investigating the effects of pioglitazone for ISR after DES implantation were identified by systematic searches of multiple online databases and manual searches of related reference lists of identified trials through May 2014. The primary endpoint was the rate of ISR. Secondary endpoints included minimum lumen diameter, percentage stenosis of stented vessels, late loss, in-stent neointimal volume, target vessel revascularization (TVR), target lesion revascularization, myocardial infarction, stent thrombosis and death.

RESULTS

Five studies, comprising 255 pioglitazone-treated patients and 245 controls, were identified in the current meta-analysis. Pioglitazone did not significantly reduce the rate of ISR (P = 0.20) with low heterogeneity (I2 = 13.3%, P = 0.32). For the secondary outcomes, pioglitazone did not substantially affect the pooled estimates of these endpoints except late loss (P = 0.01) and TVR (P = 0.04).

CONCLUSIONS

The limited evidence indicates that pioglitazone does not demonstrate markedly beneficial effect in patients subjected to coronary DES implantation. However, the results should be interpreted with care given the small sample size. Further large-scale RCTs are needed.

Are cardiovascular trial results systematically different between North America and Europe? A study based on intra-meta-analysis comparisons

BACKGROUND

It is often assumed that differences in the efficacy of treatments between countries (or regions) will be neither negligible nor minor and therefore cannot be overlooked when assessing the potential benefit of treatments in one country (or region) on the basis of trials conducted in another country (or region).

AIM

To assess differences in the results of cardiovascular trials between Europe and North America on the basis of data from an extensive collection of trials.

METHODS

A systematic search was conducted of Medline (from the year 2005 to 2008) and the Cochrane Library (from 2000 to 2008) for all meta-analyses of randomized controlled trials aimed at treating and preventing cardiovascular disease. Within each meta-analysis that satisfied given criteria, trial results were compared between Europe and North America with respect to a fatal and/or non-fatal endpoint by forming separate estimates of treatment efficacy for each of these continents.

RESULTS

The literature search found 59 meta-analyses that satisfied all the inclusion criteria. For most meta-analyses, it was the case that relative to the control, the intervention was more favoured in trials conducted in Europe than in North America with regard to both fatal endpoints (28 out of 43 meta-analyses) and non-fatal endpoints (28 out of 40 meta-analyses). However, it was only with regard to non-fatal endpoints that this imbalance turned out to be statistically significant at the 5% level (P=0.017). Also, the lack of statistically significant differences in trial results between Europe and North America within individual meta-analyses meant that it was not possible to determine for which types of intervention these intercontinental differences are likely to be more pronounced than others.

CONCLUSION

There is some evidence to support the theory that, relative to controls, interventions are more favoured in cardiovascular trials conducted in Europe than in North America, when treatment efficacy is measured in terms of a non-fatal endpoint. However, the overall support for systematic differences in cardiovascular trial results between Europe and North America is weak, which may be surprising given the amount of data collected.

Therapy in ST-elevation myocardial infarction: reperfusion strategies, pharmacology and stent selection

OPINION STATEMENT

The estimated annual incidence of new and recurrent myocardial infarction (MI) in the U.S. is 715,000 events. Primary percutaneous coronary intervention (PCI) is the reperfusion strategy of choice in most patients with acute ST-elevation myocardial infarction (STEMI). Recent advances in percutaneous techniques and devices, including manual aspiration catheters and newer generation drug eluting stents and pharmacologic therapies, such as novel antiplatelets and anticoagulants have led to significant improvements in the acute and long-term outcomes for these patients. Implementation of community-wide systems directed to shorten treatment times tied to closely monitored quality improvement processes have led to further advances in STEMI care. Recent data suggests that transradial access for primary PCI is associated with improved outcomes. This contemporary review discusses the strategies for reperfusion, pharmacological therapy and stent selection process involved in STEMI.

Influence of the angiotensin converting enzyme insertion or deletion genetic variant and coronary restenosis risk: evidence based on 11,193 subjects

The insertion/deletion (I/D) polymorphism of the gene encoding angiotensin converting enzyme is a controversial risk factor for restenosis after percutaneous transluminal coronary angioplasties (PTCA) in patients. Genetic association studies can be problematic to reproduce due to insufficient power, phenotypic heterogeneity, population stratification, small effect of the variant and even publication biases. To derive a more precise estimation of the relationship as well as to quantify the between-study heterogeneity and potential bias, a meta-analysis including 11,193 patients from 33 published cohort studies was performed. In a combined analysis, the summary per-allele odds ratio for restenosis was 1.31 (95% CI: 1.08-1.58, P = 0.006), and 1.22 (95% CI: 0.95-1.56, P = 0.12), for PTCA-stent and PTCA-balloon, respectively. In the subgroup analysis by ethnicity, significantly increased restenosis risks after PTCA-stent were found in Asians for the polymorphism; whereas no significant associations were found among Caucasians. As for restenosis risks after PTCA-balloon, no evidence of any gene-disease association was obtained in the stratified analyses according to ethnicity and study size. In conclusion, this meta-analysis demonstrated that the DD homozygous of ACE I/D polymorphism was significantly associated with elevated restenosis susceptibility after PTCA-stent among Asian populations.

Endovascular techniques in limb salvage: stents

In patients with critical limb ischemia, the first-line approach for limb salvage has shifted over the past decade from bypass surgery to endovascular intervention. Stenting for the treatment of lower-extremity arterial occlusive disease is an important tool and continues to evolve, with new stent designs and technologies that have been developed to provide superior patency rates and limb salvage. In this article, we discuss the role of peripheral stenting in the treatment of patients with critical limb ischemia, including a review of the relevant current literature and the future directions of such interventions.

Pharmacotherapy for the reduction of stent thrombosis

The benefits of percutaneous coronary intervention (PCI) can be offset by periprocedural complications such as acute vessel closure and stent thrombosis in the absence of adequate antiplatelet and antithrombotic therapy. Additionally, conditions occurring after 30 days post-PCI, such as in-stent restenosis or late stent thrombosis can occur. Excess antithrombotic therapy, on the other hand, carries a risk of major gastrointestinal or intracranial bleeding as well as vascular access site bleeding complications. In this review, evidence related to the various pharmacological agents for reduction of stent thrombosis available to clinicians during and after PCI will be explored.

Magnetic nanoparticle-based approaches to locally target therapy and enhance tissue regeneration in vivo

Magnetic-based systems utilizing superparamagnetic nanoparticles and a magnetic field gradient to exert a force on these particles have been used in a wide range of biomedical applications. This review is focused on drug targeting applications that require penetration of a cellular barrier as well as strategies to improve the efficacy of targeting in these biomedical applications. Another focus of this review is regenerative applications utilizing tissue engineered scaffolds prepared with the aid of magnetic particles, the use of remote actuation for release of bioactive molecules and magneto-mechanical cell stimulation, cell seeding and cell patterning.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSION

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

How Should We Treat Multi-Vessel Disease in STEMI Patients?

OPINION STATEMENT

Primary angioplasty of the culprit coronary artery lesion is the preferred reperfusion strategy for ST-elevation myocardial infarction (STEMI) when timely access to a catheterization laboratory is available. The presence of multi-vessel disease (MVD) in patients undergoing primary PCI is common, occurring in about 40 %-50 % of patients. The presence of MVD in patients who have undergone successful primary PCI substantially increases the risks of mortality and major adverse cardiac events, such as reinfarction or need for urgent revascularization. The current evidence supporting revascularization of non-culprit lesions is sparse, with no large, adequately powered randomized trials to guide clinical practice. An analysis combining observational data and small randomized trials suggests that complete revascularization with PCI to significant non-culprit lesions may afford a benefit compared with medical management alone. However, this benefit appears to be confined to when revascularization is performed as a separate, staged procedure. By contrast, when non-culprit lesion PCI is performed during the initial primary PCI procedure, the risk of death or cardiovascular events is higher than medical management alone or to staged revascularization. A large, adequately powered randomized trial is urgently needed to determine whether routine staged PCI plus optimal medical therapy is superior to optimal medical therapy alone for significant non-culprit coronary artery lesions in patients who have undergone successful primary PCI for STEMI.

Perioperative antiplatelet management in patients with coronary artery stenting

Coronary artery disease is the primary cause of mortality in men and women in the United States. Transcatheter coronary intervention is the mainstay of treatment for patients with acute coronary artery disease presentations and patients with stable disease. Although percutaneous intervention initially only included balloon angioplasty, it now typically involves the placement of intracoronary stents. To overcome the limitations of bare-metal stents, namely in-stent restenosis, stents have been developed that remove pharmaceuticals that reduce neointimal hyperplasia and in-stent restenosis. However, these pharmaceutical agents also delay stent endothelialization, posing a prolonged risk of in situ thrombosis. Placement of an intracoronary stent (eg, bare-metal or drug-eluting stent) requires dual antiplatelet therapy to prevent the potentially life-threatening complication of stent thrombosis. The optimal duration of dual antiplatelet therapy following stent placement is unknown. This article discusses the factors to be considered when deciding when dual antiplatelet therapy can be safely discontinued. Unfortunately, in the hospital setting, this decision to interrupt dual antiplatelet therapy frequently must be made shortly after stent placement because of unanticipated surgical procedures or other unforeseen complications. The decision of when dual antiplatelet therapy can be safely interrupted needs to be individualized for each patient and involves factoring in the type of stent; the location and complexity of the lesion stented; post-stent lesion characteristics; the amount of time since stent placement; and the antiplatelet regimen currently in use, along with its implication for bleeding during the proposed procedure. Having a protocol in place, such as the protocol described in this article, can help guide this decision-making process and avoid confusion and potential error.

Neo-intimal hyperplasia, diabetes and endovascular injury

Diabetes is a significant major risk factor for peripheral arterial disease (PAD) and critical limb ischaemia (CLI), the latter which is also the most common cause of amputation in these patients. Revascularisation of the lower extremities of such patients is imperative for limb salvage and has become First-line therapy. However, the incidence of restenosis following endovascular stenting is very high and is largely due to neo-intimal hyperplasia (NIH), the regulation of which is for the greater part not understood. This article therefore reviews our understanding on the regulation of NIH following stent-induced vascular injury, and highlights the importance of future studies to investigate whether the profile of vascular progenitor cell differentiation, neo-intimal growth factors and lumen diameters predict the severity of post-stent NIH in the peripheral arteries. Results from future studies will (1) better our understanding of the regulation of NIH in general, (2) determine whether combinations of any of the vascular factors discussed are predictive of the extent of NIH postoperatively, and (3) potentially facilitate future therapeutic targets and/or change preventive strategies.

The sirolimus-eluting Cypher Select coronary stent for the treatment of bare-metal and drug-eluting stent restenosis: insights from the e-SELECT (Multicenter Post-Market Surveillance) registry

OBJECTIVES

This study sought to compare the 1-year safety and efficacy of Cypher Select or Cypher Select Plus (Cordis Corporation, Bridgewater, New Jersey) sirolimus-eluting stents (SES) with the treatment of bare-metal stents (BMS) and drug-eluting stent (DES) in-stent restenosis (ISR) in nonselected, real-world patients.

BACKGROUND

There is paucity of consistent data on DES for the treatment of ISR, especially, DES ISR.

METHODS

The e-SELECT (Multicenter Post-Market Surveillance) registry is a Web-based, multicenter and international registry encompassing virtually all subsets of patients and lesions treated with at least 1 SES during the period from 2006 to 2008. We enrolled in this pre-specified subanalysis all patients with at least 1 clinically relevant BMS or DES ISR treated with SES. Primary endpoint was major adverse cardiac events and stent thrombosis rate at 1 year.

RESULTS

Of 15,147 patients enrolled, 1,590 (10.5%) presented at least 1 ISR (BMS group, n = 1,235, DES group, n = 355). Patients with DES ISR had higher incidence of diabetes (39.4% vs. 26.9%, p < 0.001), renal insufficiency (5.8% vs. 2.3%, p = 0.003), and prior coronary artery bypass graft (20.5% vs. 11.8%, p < 0.001). At 1 year, death (1.4% for BMS vs. 2.1% for DES, p = 0.3) and myocardial infarction (2.4% for BMS and 3.3% for DES, p = 0.3) rates were similar, whereas ischemia-driven target lesion revascularization and definite/probable late stent thrombosis were higher in patients with DES ISR (6.9% vs. 3.1%, p = 0.003, and 1.8% vs. 0.5%, p = 0.04, respectively).

CONCLUSIONS

Use of SES for either BMS or DES ISR treatment is safe and associated with low target lesion revascularization recurrence and no apparent safety concern.

Stent thrombosis: incidence, predictors and new technologies

Some concerns have been raised regarding the risk of late and very late stent thrombosis (ST) following drug-eluting stent implantation. Despite remaining an uncommon complication of percutaneous coronary intervention, when ST occurs, it can be catastrophic to the individual, commonly presenting as acute ST elevation myocardial infarction or sudden cardiac death. The incidence and predictors of ST have been reported in the literature and the role of dual antiplatelet therapies in the avoidance of such a complication remains vital. Ongoing studies are assessing the role of these therapies including platelet reactivity testing, genetic testing and optimum duration of therapy. In addition, newer polymer-free and bioabsorbable stents are under investigation in the quest to potentially minimise the risk of ST.

Endothelialization and in-stent restenosis on the surface of glycoprotein IIIa monoclonal antibody eluting stent

Since the percutaneous transtuminal coronary angioplasty was introduced into China in 1984, this procedure has become widely accepted as an important step in coronary revascularization. This study shows the effect of the monoclonal antibody (mAb) on the platelet glycoprotein IIIa receptor during endothelialization and in-stent restenosis by implanting the mAb-eluting stents into iliac arteries of rabbits. The hard tissue cross sections of the stent-implanted arterial segments were made by polymethylmethacrylate embedding. Arterial intima proliferation was observed and analyzed. The endothelialization of the stent surface was observed using scanning electron microscope, whereas the ultrastructure of the neointima was observed using transmission electron microscope. After one month of stent implantation, the surfaces of both groups were covered by intact endothelial layers, but the neointimal areas and the ratio of stenosis were significantly lesser in the mAb-eluting stent group (p < 0.01). After 3 months, the ratio of stenosis in the mAb-eluting stent group was 14.67 ± 0.79, whereas that of the bare stent group was 21.58 ± 1.76 (p < 0.01). Therefore, the mAb eluting from the stent surface has the potential to accelerate endothelialization, prevent thrombosis formation due to the interaction of stent with blood, and decrease the stenosis ratio by inhibiting neointima proliferation.

Restenosis after PCI. Part 1: pathophysiology and risk factors

Restenosis is a complex disease for which the pathophysiological mechanisms have not yet been fully elucidated, but are thought to include inflammation, proliferation, and matrix remodeling. Over the years, many predictive clinical, biological, (epi)genetic, lesion-related, and procedural risk factors for restenosis have been identified. These factors are not only useful in risk stratification of patients, they also contribute to our understanding of this condition. Furthermore, these factors provide evidence on which to base treatment tailored to the individual and aid in the development of novel therapeutic modalities. In this Review, we will evaluate the available evidence on the pathophysiological mechanisms of restenosis and provide an overview of the various risk factors, together with the possible clinical application of this knowledge.

A genome-wide association study identifies a region at chromosome 12 as a potential susceptibility locus for restenosis after percutaneous coronary intervention

Percutaneous coronary intervention (PCI) has become an effective therapy to treat obstructive coronary artery diseases (CAD). However, one of the major drawbacks of PCI is the occurrence of restenosis in 5-25% of all initially treated patients. Restenosis is defined as the re-narrowing of the lumen of the blood vessel, resulting in renewed symptoms and the need for repeated intervention. To identify genetic variants that are associated with restenosis, a genome-wide association study (GWAS) was conducted in 295 patients who developed restenosis (cases) and 571 who did not (controls) from the GENetic Determinants of Restenosis (GENDER) study. Analysis of ~550 000 single nucleotide polymorphisms (SNPs) in GENDER was followed by a replication phase in three independent case-control populations (533 cases and 3067 controls). A potential susceptibility locus for restenosis at chromosome 12, including rs10861032 (P(combined) = 1.11 × 10(-7)) and rs9804922 (P(combined) = 1.45 × 10(-6)), was identified in the GWAS and replication phase. In addition, both SNPs were also associated with coronary events (rs10861032, P(additive) = 0.005; rs9804922, P(additive) = 0.023) in a trial based cohort set of elderly patients with (enhanced risk of) CAD (PROSPER) and all-cause mortality in PROSPER (rs10861032, P(additive) = 0.007; rs9804922, P(additive) = 0.013) and GENDER (rs10861032, P(additive) = 0.005; rs9804922, P(additive) = 0.023). Further analysis suggests that this locus could be involved in regulatory functions.