Revisiting the Evidence for Dipyridamole in Reducing Restenosis: A Systematic Review and Meta-analysis

ABSTRACT

Atherosclerosis remains a leading cause of morbidity and mortality, with revascularization remaining a cornerstone of management. Conventional revascularization modalities remain challenged by target vessel reocclusion-an event driven by mechanical, thrombotic, and proliferative processes. Despite considerable advancements, restenosis remains the focus of ongoing research. Adjunctive agents, including dipyridamole, offer a multitude of effects that may improve vascular homeostasis. We sought to quantify the potential therapeutic impact of dipyridamole on vascular occlusion. We performed a literature search (EMBASE and MEDLINE) examining studies that encompassed 3 areas: (1) one of the designated medical therapies applied in (2) the setting of a vascular intervention with (3) an outcome including vascular occlusion rates and/or quantification of neointimal proliferation/restenosis. The primary outcome was vascular occlusion rates. The secondary outcome was the degree of restenosis by neointimal quantification. Both human and animal studies were included in this translational analysis. There were 6,839 articles screened, from which 73 studies were included, encompassing 16,146 vessels followed up for a mean of 327.3 days (range 7-3650 days). Preclinical studies demonstrate that dipyridamole results in reduced vascular occlusion rates {24.9% vs. 48.8%, risk ratio 0.53 [95% confidence interval (CI) 0.40-0.70], I2 = 39%, P < 0.00001}, owing to diminished neointimal proliferation [standardized mean differences -1.13 (95% CI -1.74 to -0.53), I2 = 91%, P = 0.0002]. Clinical studies similarly demonstrated reduced occlusion rates with dipyridamole therapy [23.5% vs. 31.0%, risk ratio 0.77 (95% CI 0.67-0.88), I2 = 84%, P < 0.0001]. Dipyridamole may improve post-intervention vascular patency and mitigate restenosis. Dedicated studies are warranted to delineate its role as an adjunctive agent after revascularization.

Predictive value of LncRNA on coronary restenosis after percutaneous coronary intervention in patients with coronary heart disease: A protocol for systematic review and meta-analysis

BACKGROUND

Evidence shows that long-stranded non-coding RNA (LncRNA) can predict coronary artery restenosis in patients suffering from coronary heart disease after percutaneous coronary intervention, suggesting that LncRNA may become a promising biomarker for the diagnosis of coronary artery restenosis after percutaneous coronary intervention. However, its accuracy has not been systematically evaluated. Therefore, it is necessary to perform meta-analysis to certify the diagnostic value of LncRNA on coronary artery restenosis after percutaneous coronary intervention.

METHODS

PubMed, EMBASE, Cochrane Library, and Web of Science were searched for relevant studies to explore the potential diagnostic values of LncRNA on coronary artery restenosis after percutaneous coronary intervention from inception to December 2020. Data were extracted by two experienced researchers independently. The risk of bias about the meta-analysis was confirmed by the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). Data was synthesized and heterogeneity was investigated as well. All of the above statistical analysis was carried out with Stata 14.0.

RESULTS

This study proved the pooled diagnostic performance of LncRNA on coronary artery restenosis after percutaneous coronary intervention.

CONCLUSION

This study clarified confusions about the specificity and sensitivity of LncRNA on coronary artery restenosis after percutaneous coronary intervention, thus further guiding their promotion and application.

ETHICS AND DISSEMINATION

Ethical approval is not required for this study. The systematic review will be published in a peer-reviewed journal, presented at conferences, and shared on social media platforms. This review would be disseminated in a peer-reviewed journal or conference presentations.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/4QT2P.

The adipokine vaspin is associated with decreased coronary in-stent restenosis in vivo and inhibits migration of human coronary smooth muscle cells in vitro

BACKGROUND

Percutaneous coronary intervention represents the most important treatment modality of coronary artery stenosis. In-stent restenosis (ISR) is still a limitation for the long-term outcome despite the introduction of drug eluting stents. It has been shown that adipokines directly influence vessel wall homeostasis by influencing the function of endothelial cells and arterial smooth muscle cells. Visceral adipose tissue-derived serpin vaspin was recently identified as a member of serine protease inhibitor family and serveral studies could demonstrate a relation to metabolic diseases. The aim of this study was to investigate a role of vaspin in the development of in-stent restenosis in vivo and on migration of smooth muscle cells and endothelial cells in vitro.

METHODS

We studied 85 patients with stable coronary artery disease who underwent elective and successful PCI with implatation of drug eluting stents. Blood samples were taken directly before PCI. Vaspin plasma levels were measured by specific ELISA. ISR was evaluated eight months later by coronary angiography. Human coronary artery smooth muscle cells (HCASMC) and human umbilical vein endothelial cells (HUVEC) migration was analyzed by an in-vitro migration assay with different concentrations (0.004ng/mL up to 40ng/mL) of vaspin as well as by an scratch assay. For proliferation an impedance measurement with specialiced E-Plates was performed.

RESULTS

During the follow up period, 14 patients developed ISR. Patients with ISR had significantly lower vaspin plasma levels compared to patients without ISR (0.213 ng/ml vs 0.382 ng/ml; p = 0.001). In patients with plasma vaspin levels above 1.35 ng/ml we could not observe any restenosis. There was also a significant correlation of plasma vaspin levels and late lumen loss in the stented coronary segments. Further we could demonstrate that vaspin nearly abolishes serum induced migration of HCASMC (100% vs. 9%; p<0.001) in a biphasic manner but not migration of HUVEC. Proliferation of HCASMC and HUVEC was not modulated by vaspin treatment.

CONCLUSION

We were able to show that the adipokine vaspin selectively inhibits human coronary SMC migration in vitro and has no effect on HUVEC migration. Vaspin had no effect on proliferation of HUVEC which is an important process of the healing of the stented vessel. In addition, the occurrence of ISR after PCI with implantation of drug eluting stents was significantly associated with low vaspin plasma levels before intervention. Determination of vaspin plasma levels before PCI might be helpful in the identification of patients with high risk for development of ISR after stent implantation. In addition, the selective effects of vaspin on smooth muscle cell migration could potentially be used to reduce ISR without inhibition of re-endothelialization of the stented segment.

Role of endothelial dysfunction in determining angina after percutaneous coronary intervention: Learning from pathophysiology to optimize treatment

Endothelial dysfunction (EnD) is a hallmark feature of coronary artery disease (CAD), representing the key early step of atherosclerotic plaque development and progression. Percutaneous coronary intervention (PCI) is performed daily worldwide to treat symptomatic CAD, however a consistent proportion of patients remain symptomatic for angina despite otherwise successful revascularization. EnD plays a central role in the mechanisms of post-PCI angina, as it is strictly associated with both structural and functional abnormalities in the coronary arteries that may persist, or even accentuate, following PCI. The assessment of endothelial function in patients undergoing PCI might help to identify those patients at higher risk of future cardiovascular events and recurrent/persistent angina who might therefore benefit more from an intensive treatment. In this review, we address the role of EnD in determining angina after PCI, discussing its pathophysiological mechanisms, diagnostic approaches and therapeutic perspectives.

Longitudinal Stent Deformation: Precise Diagnosis With Optical Coherence Tomography

Longitudinal stent deformation is a recognized complication of coronary angioplasty; however, it is difficult to detect angiographically. This case illustrates the value of OCT to identify and correctly diagnose longitudinal stent deformation.

Real World Utilization of Computed Tomography Derived Fractional Flow Reserve: Single Center Experience in the United States

BACKGROUND

Fractional flow reserve derived from computed tomography (FFRct) has shown higher accuracy for detection of significant coronary artery disease (CAD) compared to coronary computed tomography angiography (CCTA). The performance of a combined comprehensive qualitative interpretation of both CCTA and FFRct in patient management is unknown. We aimed to explore the clinical application of this combined approach.

METHODS

We retrospectively reviewed cases referred to FFRct testing at our institution over a one-year period. Patients had documentation of whether invasive coronary angiography (ICA) was performed and revascularization were needed. Interpretations and recommendations of the adopted comprehensive approach (C-FFRct), that took into account focal versus diffuse disease, depth of ischemia and myocardium at risk, were compared to those of CCTA (binary > 50% stenosis) alone and FFRct binary approach (FFRct ≤ 0.8). C-FFRct performance was measured against the decision made upon revascularization.

RESULTS

A total of 207 cases were referred to FFRct testing, 163 (79%) accepted and 44 (21%) rejected for quality. C-FFRct changed interpretations and recommendations of 39 (24%) and 14 (9%) CCTA and FFRct, respectively. ICA was deferred in 32 (59%) and 13 (32%) cases; whereas ICA referral rate was 7 (6%) and 1 (0.8%) cases, based on CCTA and FFRct, respectively. No major cardiac events were observed during follow up time (median = 6 months). C-FFRct sensitivity, specificity, and accuracy compared to decision upon revascularization were 89%, 79% and 82%. C-FFRct number needed to treat was 4, and 6, compared to CCTA and FFRct, respectively.

CONCLUSION

FFRct is a feasible tool to improve the diagnostic performance of CCTA in CAD real-world workup. However, qualitative interpretation of the FFRct report combined with CCTA findings may yield more impactful results on patient management. Further prospective studies are warranted to validate the application of this approach and better define its components.

Epac1 deficiency inhibits basic fibroblast growth factor-mediated vascular smooth muscle cell migration

Vascular smooth muscle cell (VSMC) migration and the subsequent intimal thickening play roles in vascular restenosis. We previously reported that an exchange protein activated by cAMP 1 (Epac1) promotes platelet-derived growth factor (PDGF)-induced VSMC migration and intimal thickening. Because basic fibroblast growth factor (bFGF) also plays a pivotal role in restenosis, we examined whether Epac1 was involved in bFGF-mediated VSMC migration. bFGF-induced lamellipodia formation and migration were significantly decreased in VSMCs obtained from Epac1-/- mice compared to those in Epac1+/+-VSMCs. The bFGF-induced phosphorylation of Akt and glycogen synthase kinase 3β (GSK3β), which play a role in bFGF-induced cell migration, was attenuated in Epac1-/--VSMCs. Intimal thickening induced by the insertion of a large wire was attenuated in Epac1-/- mice, and was accompanied by the decreased phosphorylation of GSK3β. These data suggest that Epac1 deficiency attenuates bFGF-induced VSMC migration, possibly via Akt/GSK3β pathways.

Fufang-Zhenzhu-Tiaozhi Capsule reduces restenosis via the downregulation of NF-kappaB and inflammatory factors in rabbits

BACKGROUND

To investigate the effects of a Chinese herbal medicine Fufang-Zhenzhu Tiaozhi Capsule (FTZ) on restenosis and elucidate the mechanism of action.

METHODS

A restenosis model was established by balloon rubbing the endothelium of the abdominal aorta followed by high fat diet. Rabbits were divided into blank control group, restenosis group, FTZ group (0.66 mg/kg/day), atorvastatin group (5 mg/kg/day) and FTZ + atorvastatin group (n = 8). Vascular stenosis was analyzed by X-ray. Serum levels of chemokines and cytokines interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-12 (IL-12), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and intercellular adhesion molecule-1 (ICAM-1) were measured by ELISA. The levels of NF-κB, IκB-α, P-IκBα, IKK-α, and P-IKKα/β from injured abdominal arteries were detected by Western blotting.

RESULTS

Restenosis was induced successfully via abdominal artery balloon injuries and high fat diet. Restenosis was significantly decreased in FTZ group compared with restenosis group (P < 0.05). FTZ group had markedly reduced serum lipid levels (P < 0.05). In addition, the levels of TNF-α, IL-1, IL-6, IL-8, IL-12, ICAM-1 and MCP-1 decreased by FTZ treatment (P < 0.05). The expression of NF-κB in the atherosclerotic lesions was significantly attenuated in FTZ group (P < 0.05).

CONCLUSION

FTZ could reduce restenosis via reducing NF-κB activity and inflammatory factor expression within the atherosclerotic lesion in a rabbit restenosis model. FTZ may be a new therapeutic agent for restenosis.

Diagnostic accuracy of coronary CT angiography performed in 100 consecutive patients with coronary stents using a whole-organ high-definition CT scanner

AIMS

To evaluate image quality, interpretability, diagnostic accuracy and radiation exposure of coronary CT angiography (CCTA) performed with a new scanner equipped with 0.23-mm spatial resolution, new generation iterative reconstruction, 0.28-second gantry rotation time and intra-cycle motion-correction algorithm in consecutive patients with coronary stents, including those with high heart rate (HR) and atrial fibrillation (AF).

MATERIALS AND METHODS

We enrolled 100 consecutive patients (85 males, mean age 65 ± 10 years) with previous coronary stent implantation scheduled for clinically indicated non-emergent invasive coronary angiography (ICA). Image quality, coronary interpretability and diagnostic accuracy vs. ICA were evaluated and the effective dose (ED) was recorded.

RESULTS

Mean HR during the scan was 67 ± 13 bpm. Twenty-six patients had >65 bpm HR during scanning and 13 patients had AF. Overall, image quality was high (Likert = 3.2 ± 0.9). Stent interpretability was 95.8% (184/192 stents). Among 192 stented segments, CCTA correctly identified 22 out of 24 with >50% in-stent restenosis (ISR) (sensitivity 92%). In a stent-based analysis, specificity, positive and negative predictive values and diagnostic accuracy for ISR detection were 91%, 99%, 60% and 91%, respectively. In a patient-based analysis, CCTA diagnostic accuracy was 85%. Overall, mean ED of CCTA was 2.4 ± 1.2 mSv.

CONCLUSIONS

A whole-organ CT scanner was able to evaluate coronary stents with good diagnostic performance and low radiation exposure, also in presence of unfavorable HR and heart rhythm.

TRANSLATIONAL ASPECT

The present study is the first to evaluate the CCTA capability of detecting in-stent restenosis in consecutive patients, including those with high HR and AF, using a recent scanner generation that combines improved spatial and temporal resolution with wide coverage. Using the whole-organ high-definition CT scanner we obtained high quality images of coronary stents with good interpretability and diagnostic accuracy combined with low radiation exposure, even in patients with unfavorable HR or heart rhythm for CCTA evaluation.

Immediate Therapeutic Outcomes and Medium-term Follow-up of Percutaneous Balloon Pulmonary Valvuloplasty in Infants with Pulmonary Valve Stenosis: A Single-center Retrospective Study

BACKGROUND

Percutaneous balloon pulmonary valvuloplasty (PBPV) is the preferred therapy for pulmonary valve stenosis (PVS). This study retrospectively reviewed recent PBPV outcomes in infants with PVS. The aim of this study was to evaluate factors associated with immediate therapeutic outcomes and restenosis during medium-term follow-up.

METHODS

The study included 158 infants with PVS who underwent PBPV from January 2009 to July 2015. Demographic characteristics and patient records were reviewed, including detailed hospitalization parameters, hemodynamic data before and immediately after balloon dilation, cineangiograms, and echocardiograms before PBPV and at each follow-up. All procedures were performed by more than two experienced operators.

RESULTS

Immediately after balloon dilation, the pressure gradient across the pulmonary valve decreased from 73.09 ± 21.89 mmHg (range: 43-151 mmHg) to 24.49 ± 17.00 mmHg (range: 3-92 mmHg; P < 0.001) and the right ventricular systolic pressure decreased from 95.34 ± 23.44 mmHg (range: 60-174 mmHg) to 52.07 ± 18.89 mmHg (range: 22-134 mmHg; P < 0.001). Residual transvalvular pressure gradients of 67.31 ± 15.19 mmHg (range: 50-92 mmHg) were found in 8.2% of patients, indicating poor therapeutic effects; 6.4% of patients had variable-staged restenosis at follow-up and 3.8% underwent reintervention by balloon dilation or surgical repairs. Further analysis demonstrated that the balloon/annulus ratio showed statistically significant differences (P < 0.05) among groups with different therapeutic effects and between the restenosis and no-stenosis groups. Binary logistic regression analysis further revealed that higher balloon/annulus ratio (odds ratio: 0.005, 95% confidence interval: 0-0.39) was an independent protective factor for restenosis. The rate of severe complications was 1.9%.

CONCLUSIONS

PBPV is a definitive therapy for infants with PVS based on its effectiveness, feasibility, and safety. Restenosis upon medium-term follow-up is relatively rare.

Restenosis after Coronary and Peripheral Intervention: Efficacy and Clinical Impact of Cilostazol

Restenosis is one of the main complications in patients undergoing coronary or peripheral revascularization procedures and is the leading cause for their long-term failures. Cilostazol is the only pharmacotherapy that showed an adequate efficacy for preventing restenosis in randomized, controlled studies after coronary or peripheral revascularization procedures. The present review sums up the main clinical evidence supporting the use of cilostazol after revascularization interventions, focusing on all its benefits, warnings, and administration schedules.

QT Dispersion and Age; Independent Predictors of Restenosis after Percutaneous Coronary Intervention

INTRODUCTION

There are no reliable non-invasive markers of restenosis after Percutaneous Coronary Interventions (PCIs). The aim of our study was to measure changes incorrected QT interval (QTc), corrected QT dispersion (QTcd), corrected T wave peak to end interval (TPEc) and corrected TPE dispersion (TPEcd) after PCI and to determine whether restenosis subsequently affects these indices.

METHODS

From 211 patients, who underwent successful PCI, 202 patients were referred for repeated coronary angiography in order to exclusion of coronary restenosis and included in this analysis. QTc, QTcd, TPEc and TPEcd indices were calculated just before PCI and 24 hours later.

RESULTS

Comparing pre procedural with post procedural results, median QTc and median QTcd decreased significantly after PCI procedure (from 447 to 440 ms, p=0.017 and from 46 to 40 ms,p=0.005; respectively). Corresponding changes of TPEc and TPEcD were not statistically significant. Multivariate analysis showed higher amounts of QTcd changes [Exp(B): 1.033, 95% CI: 1.018-1.051; P=0.025] and younger age[Exp(B): 1.074, 95% CI: 1.038-1.112; P=0.023] as independent predictors of restenosis. Area under the ROC curve indicated good predictive performance of QTcd changes (.QTcd) [AUC: 0.71, 95% CI: 0.51-0.86, P = 0.03] and age [AUC 0.68, 95% CI 0.62-0.74, p = 0.04] for restenosis after PCI. The best cut-off point for .QTcd was 6 msec, and for age was 52 years. The sensitivity and specificity of .QTcd.6 ms to detect coronary restenosis were 73.2% and 71.4% respectively. The diagnostic accuracy of age was also similar, the sensitivity and specificity of age. 52 years were 68.1% and 74.3% respectively.

CONCLUSION

The Higher differences between pre and post PCI QTcd may be an inexpensive and simple predictor of restenosis after a previously successful coronary angioplasty. It seems that these findings encourage us to re-think about using QTcd as a simple ECG predictor for sustained coronary patency after angioplasty.

The Difference Between Success and Failure: Subintimal Stenting Around an Occluded Stent for Treatment of a Chronic Total Occlusion Due to In-Stent Restenosis

We present a case where conventional wire and equipment passage through the proximal cap of a chronic total occlusion due to in-stent restenosis was not possible. The lesion was then safely and successfully treated by deliberate passage into the subintimal space outside the previous stent with subsequent subintimal dissection and reentry into the true lumen beyond the occlusion. We then stented around the occluded stent, effectively crushing the previous stent in the true lumen and restoring flow by stenting open the new subintimal lumen. Follow-up angiography and optical coherence tomography at 6 months demonstrated good medium-term results.

MicroRNAs for Restenosis and Thrombosis After Vascular Injury

Percutaneous revascularization revolutionized the therapy of patients with coronary artery disease. Despite continuous technical advances that substantially improved patients' outcome after percutaneous revascularization, some issues are still open. In particular, restenosis still represents a challenge, even though it was dramatically reduced with the advent of drug-eluting stents. At the same time, drug-eluting stent thrombosis emerged as a major concern because of incomplete or delayed re-endothelialization after vascular injury. The discovery of microRNAs revealed a previously unknown layer of regulation for several biological processes, increasing our knowledge on the biological mechanisms underlying restenosis and stent thrombosis, revealing novel promising targets for more efficient and selective therapies. The present review summarizes recent experimental and clinical evidence on the role of microRNAs after arterial injury, focusing on practical aspects of their potential therapeutic application for selective inhibition of smooth muscle cell proliferation, enhancement of endothelial regeneration, and inhibition of platelet activation after coronary interventions. Application of circulating microRNAs as potential biomarkers is also discussed.

Intracoronary Brachytherapy for Recurrent Drug-Eluting Stent Failure

OBJECTIVES

The study sought to report safety and long-term clinical efficacy of intravascular brachytherapy (VBT) for recurrent drug-eluting stent in-stent restenosis (DES-ISR).

BACKGROUND

Recurrent DES-ISR remains a therapeutic challenge, and VBT has been used selectively in recurrent DES failure.

METHODS

Patients undergoing VBT for recurrent DES-ISR were enrolled from a percutaneous coronary intervention registry. Clinical, procedural, VBT, and outcome data were collected for DES-ISR treated with radiation. Follow-up was obtained by phone call and clinic visits.

RESULTS

A total of 186 patients (283 lesions) were included. Mean age was 65 ± 11 years, and 115 (61.8%) were men. Mean time to failure from last failed DES implantation was 450.65 ± 50 days. Majority (95%) had >2 episodes of target lesion revascularization (TLR). Commonest presentation of DES-ISR was unstable angina (68, 30%). All lesions were treated with balloon angioplasty followed by VBT using Beta-Cath system (Best Vascular Inc., Springfield, Virginia) with a dose of 23 to 25 Gy at 2 mm from source center. Radiation was delivered to site of ISR, without procedural adverse events, in 99% cases. Incidence of TLR was 3.3% at 6 months, 12.1% at 1 year, 19.1% at 2 years, and 20.7% at 3 years. No subacute thrombosis event was noted. One patient had late thrombosis during a 3-year follow-up.

CONCLUSIONS

VBT for recurrent DES-ISR is safe, with low recurrence rates at 12 months post-procedure, and can be safely used as an effective short-term strategy. Overtime, there is a gradual attrition in patency requiring repeat intervention.

Impaired Peripheral Endothelial Function Assessed by Digital Reactive Hyperemia Peripheral Arterial Tonometry and Risk of In-Stent Restenosis

Background

Drug‐eluting stents are replacing bare‐metal stents, but in‐stent restenosis (ISR) remains a problem. Reactive hyperemia index (RHI) assessed by peripheral arterial tonometry evaluates endothelial function noninvasively. We prospectively assessed the prognostic value of RHI in predicting ISR after percutaneous coronary intervention.

Methods and Results

RHI was measured before percutaneous coronary intervention and at follow‐up (F/U) angiography (F/U RHI; 6 and 9 months post bare‐metal stents– and drug‐eluting stents– percutaneous coronary intervention, respectively) in 249 consecutive patients. At F/U, ISR (stenosis >50% of diameter) was seen in 68 patients (27.3%). F/U natural logarithm (RHI) was significantly lower in patients with ISR than in those without (0.52±0.23 versus 0.65±0.27, P<0.01); no between‐group difference in initial natural logarithm (RHI) (0.60±0.26 versus 0.62±0.25, P=0.56) was seen. By multivariate logistic regression analysis, even after adjusting for other significant parameters in univariate analysis, F/U natural logarithm (RHI) independently predicted ISR (odds ratio: 0.13; 95% CI: 0.04–0.48; P=0.002). In receiver operating‐characteristic analysis, F/U RHI was the strongest predictor of ISR (area under the curve: 0.67; 95% CI: 0.60–0.75; P<0.01; RHI <1.73 had 67.6% sensitivity, 64.1% specificity); area under the curve significantly improved from 0.62 to 0.70 when RHI was added to traditional ISR risk factors (P=0.02). Net reclassification index was significant after addition of RHI (26.5%, P=0.002).

Conclusions

Impaired RHI at F/U angiography independently correlated with ISR, adding incremental prognostic value to the ISR‐risk stratification following percutaneous coronary intervention.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02131935.

MicroRNAs as circulating biomarkers in acute coronary syndromes: A review

Coronary artery disease (CAD) and its complications remain the most common cause of death worldwide. Cardiac troponins (cTn) are standard biomarkers used today for diagnosis and risk stratification of myocardial infarction (MI). Increasing efforts are made to develop additional, new biomarkers for more effective and safe rule-in and rule-out of MI patients at the emergency department. During the past decade, microRNAs (miRNAs) have emerged as new, potential diagnostic biomarkers in several diseases, including MI. In this review, we aimed to summarize some of the prominent studies in the field, and discuss the potential value of miRNAs in the diagnosis of MI.

The Same Angiographic Factors Predict Venous and Arterial Graft Patency: A Retrospective Study

To evaluate the value of angiographic factors in predicting failure of both venous and arterial coronary artery bypass graft. We retrieved from our angiographic database 148 patients who underwent venous and/or arterial CABG and for whom a control coronary angiography at more than 1 month after surgery was available. Pre-CABG and follow-up angiographies were analyzed in order to evaluate diameter stenosis (DS,%), stenosis length (mm), Bogaty score (extent index), Sullivan score, and Gensini score for the extent of coronary artery disease, and Jeopardy Duke score for the extent of myocardial area supplied by an artery. Thirty-nine patients (26%) experienced graft failure at follow-up (mean follow-up 11.3 ± 4.6 months). Patients with venous graft failure [26 (20%)] had significantly smaller DS (P = 0.013), shorter stenosis length (P = 0.01), and lower extent index (P = 0.015), Sullivan score (P = 0.013), Gensini score (P = 0.04) as compared with those without venous graft failure. Patients with arterial graft failure [13 (11%)] had significantly lower DS (P = 0.008), shorter stenosis length (P = 0.001), and lower extent index (P = 0.03) and Sullivan score (P = 0.023) as compared with those without arterial graft failure. Venous and arterial graft failure are associated with less severe stenosis and less extensive atherosclerosis of the grafted vessel.

The AngiographiC Evaluation of the Everolimus-Eluting Stent in Chronic Total Occlusion (ACE-CTO) Study

BACKGROUND

There are limited data on outcomes after implantation of second-generation drug-eluting stents in coronary chronic total occlusions (CTOs). We aimed to evaluate the frequency of angiographic restenosis and clinical outcomes after implantation of the everolimus-eluting stent (EES) in coronary CTOs.

METHODS

One hundred patients undergoing successful CTO percutaneous coronary intervention using EES at our institution between 2009 and 2012 were enrolled. The primary study endpoint was binary in-segment restenosis at 8-month follow-up quantitative coronary angiography. Secondary endpoints included death, myocardial infarction, target-lesion and target-vessel revascularization, and symptom improvement.

RESULTS

Mean age was 64 ± 7 years and 99% of the patients were men. The successful crossing technique was antegrade wiring in 51 patients, antegrade dissection/reentry in 24 patients, and retrograde in 25 patients. Binary angiographic restenosis occurred in 46% of the patients (95% confidence interval [CI], 35%-57%). The pattern of restenosis was focal, proliferative, and total occlusion in 19 lesions (46%), 14 lesions (34%), and 8 lesions (20%), respectively. At 12 months, the incidences of death, myocardial infarction, target-lesion revascularization, and target-vessel revascularization were 2%, 2%, 37%, and 39%, respectively. At 12 months, symptoms were improved, unchanged, or worse compared with baseline in 89 patients, 8 patients, and 1 patient, respectively (2 patients died before the 12-month follow-up). On multivariable analysis, smaller stent diameter was associated with higher risk for binary angiographic restenosis.

CONCLUSION

High rates of angiographic restenosis and repeat revascularization were observed among patients receiving EES in coronary CTOs, but most had significant symptom improvement.

Angiotensin type 1 receptor A1166C gene polymorphism is associated with endothelial dysfunction and in-stent restenosis after percutaneous coronary intervention

BACKGROUND AND PURPOSE

Percutaneous coronary intervention (PCI) has been commonly used in the treatment of ischemic cardiovascular diseases, but the postprocedural in-stent restenosis (ISR) associated with altered endothelial functions has limited the clinical application of it; preventive medication with aspirin and statins has underlying adverse effects despite lowered risk of ISR. The purpose of this study was to investigate the role of angiotensin type 1 receptor (AT1R) A1166C gene polymorphisms in the development of endothelial dysfunction and ISR after PCI.

METHODS

A total of 483 ST-segment elevation myocardial infarction (STEMI) patients undergoing PCI were prospectively genotyped using polymerase chain reaction (PCR) and restriction fragment length polymorphism assay. The demographic, clinical, laboratory and angiographic parameters were recorded peri-procedurally and the patients were followed within 3 years. The flow-mediated dilation (FMD) was used to reflect the short-term changes in endothelial functions among different genotypes. The significance of AT1R gene polymorphisms in the development of ISR was analyzed using univariable and multivariable models.

RESULTS

Amongst 483 patients, the distribution of the AT1R genotypes (AA, AC and CC) was associated with the levels of blood biomarkers of oxidative stress and deteriorated FMD after PCI (P<0.05). In univariable and multivariable logistic regression analysis, it was shown that AT1R CC genotype is strongly associated with the development of restenosis within 3 years after PCI (OR=3.736; P<0.001; calibrated OR=4.104; P<0.001).

CONCLUSION

The CC AT1R genotype was associated with deteriorated endothelial functions in the target vessels of PCI and intermediate to long-term ISR. Our findings contribute to the foundation of genome-based prevention for high risk groups of cardiovascular diseases and pretreatment for the patients undergoing PCI.

Hyperglycemia has no effect on development of restenosis after percutaneous transluminal angioplasty (PTA) in a diabetic rabbit model

It is well known that hyperglycemia is a trigger of atherosclerosis in patients with diabetes mellitus. However, the role of hyperglycemia in restenosis remains unclear. In this study, we investigated the effects of hyperglycemia on restenosis. Stenosis was evaluated in two sets of diabetic rabbit models: i) diabetic restenosis versus nondiabetic restenosis and ii) diabetic atherosclerosis versus nondiabetic atherosclerosis. Our results indicated that there was no difference in rates of stenosis between the diabetic and the nondiabetic groups in restenosis rabbit models. However, the incidence of stenosis was significantly higher in the diabetic atherosclerosis group compared with the nondiabetic atherosclerosis group. Similarly, the intima-media thickness and cell proliferation rate were significantly increased in the diabetic atherosclerosis group compared with the nondiabetic atherosclerosis group, but there was no difference between the diabetic restenosis and the nondiabetic restenosis groups. Our results indicate that hyperglycemia is an independent risk factor for atherosclerosis, but it has no evident effect on restenosis. These findings indicate that the processes of atherosclerosis and restenosis may involve different pathological mechanisms.

Use of graft flow measurement and computerized tomography angiography to evaluate patency of endoscopically harvested radial artery as sequential graft in coronary artery bypass surgery

AIM

Endoscopic radial artery (RA) graft harvesting in coronary artery bypass surgery (CABG) is attractive but concern remains regarding early graft failure. We evaluated RA graft patency via intraoperative graft flow measurements and mid-term computerized tomography angiography (CTA).

METHODS

The patients who had RA harvested by endoscopic technique which was used as sequential grafts were retrospectively reviewed. Graft quality was confirmed by intraoperative transit time flow measurements. Graft stenosis was defined as stenosis >70% on CTA, 6-12 months postoperatively.

RESULTS

From 2007 to 2011, 58 patients underwent endoscopic RA harvesting for sequential bypassed grafts. All received total arterialized grafts, including 22 (38%) bilateral internal thoracic arteries (ITAs), with 208 total bypassed grafts (mean: 3.59±0.52) and 128 RA bypassed grafts (mean: 2.21±0.35). Off-pump technique was performed in 43 (84%) of 51 isolated CABG patients. The pulsatility index of graft flow of the left, right ITA and sequential RA grafts with 2 or 3 targets were 1.8±0.7, 2±0.8, 1.9±0.4, and 1.7±0.7, respectively. There was no hospital mortality, and median intensive care unit and hospital stay was 2 and 8 days. Follow-up was completed in 57 patients, but 3 patients refused CTA due to lack of exertional angina. Stenosis of the left, right ITA, and RA grafts occurred in 1/54 (1.9%), 1/21 (4.8%), and 11/120 (9.2%). After a mean of 35.8±10.9 (median: 30.7) months follow-up, there was no late mortality and one documented myocardial infarction was reported. Age, diabetes, previous percutaneous coronary intervention, off-pump technique, RA target number, and graft flow or pulsatility index did not predict RA stenosis. Only RA grafts targeting the circumflex territory had an adverse impact.

CONCLUSION

The RA of appropriately selected patients can be harvested safely by endoscopic technique and can be used as sequential grafts for CABG with satisfactory outcomes. Intraoperative flow measurement can assure the quality of the grafts. CTA is a valuable tool for patency follow-up.

Interfacial biology of in-stent restenosis

Percutaneous angioplasty is a nonsurgical method able to restore patency in atherosclerotic blood vessels through the expansion of a balloon. The clinical outcome of this technique has been significantly enhanced by the combined deployment of a stent. Although stents are successful in the majority of cases, a large percentage of patients (20-30%) still suffer a second vessel lumen reduction known as in-stent restenosis. In-stent restenosis is recognized to be caused by the mechanical and foreign body challenges elicited by the device. Drug-eluting stents have been recently made available to tackle restenosis, but their short clinical history and high costs may limit their future use. The present review links the most recent biologic findings related to in-stent restenosis to the devices' phyisico-chemical features in an attempt to demonstrate that a new generation of stents may be developed without the need of drug elution.

Contributors to newly developed coronary artery disease in patients with a previous history of percutaneous coronary intervention beyond the early phase of restenosis

OBJECTIVE

The low-density lipoprotein cholesterol (LDL-C)/high-density lipoprotein cholesterol (HDL-C) ratio is considered to be a sensitive marker of the risk of atherosclerotic cardiovascular disease; however, in patients with a previous history of percutaneous coronary intervention (PCI), there is little information regarding the predictive value of this parameter beyond the period of early restenosis. The aim of this study was to investigate contributing factors to newly developed coronary artery disease in patients with a previous history of PCI after stabilization.

METHODS

The clinical characteristics of 238 patients with a previous history of PCI who underwent coronary angiography following recurrent cardiac ischemia beyond the period of early restenosis were examined.

RESULTS

Overall, 64% of the patients underwent late revascularization, while 31% and 50% underwent late target lesion revascularization and new lesion revascularization, respectively. A multivariate analysis identified the LDL-C/HDL-C ratio to be an independent contributor to late revascularization (hazard ratio (HR), 1.37; p<0.001). Similarly, the independent contributors to late target lesion revascularization and new lesion revascularization were the non-HDL-C level and LDL-C/HDL-C ratio, respectively. Based on the median value of the LDL-C/HDL-C ratio, the patients were classified into high and low LDL-C/HDL-C ratio groups. The log-rank test revealed a significantly higher incidence of late revascularization in the high-LDL-C/HDL-C ratio group than in the low-LDL-C/HDL-C ratio group among the patients with an LDL-C level of ≥ 100 mg/dL (p=0.011). However, the difference between the two groups was diminished among the patients with an LDL-C level of <100 mg/dL (p=0.047), and only diabetes mellitus (HR, 2.239; p=0.009) was found to be an independent contributor to late coronary revascularization in these patients.

CONCLUSION

The LDL-C/HDL-C ratio is an important contributor to the development of new coronary artery disease in patients with a previous history of PCI beyond the period of early restenosis, particularly among patients with an LDL-C level of ≥ 100 mg/dL.

Treatment of in-stent restenosis involving a bifurcation lesion with a dedicated bifurcation device in combination with drug-eluting balloons

It can be difficult to find a good treatment strategy in cases with in-stent restenosis with involvement of a bifurcation lesion. To avoid multiple stent layers and to treat the bifurcation lesion properly, the patient described in this case report was treated with a Tryton side branch stent and drug-eluting balloons. Angiographic follow-up at 8 months showed an excellent result.

Percutaneous coronary intervention in patients with anomalous origin of coronary artery

Percutaneous coronary intervention in patients with anomalous origin of right coronary artery from left sinus of Valsalva was performed in Central Chest Institute during 2005-2009. The diagnosis of this type of congenital anomaly is always difficult, since it requires high operator's consideration and experience. Standard catheter curve desired for general coronary angiography is also not suitable for the abnormal origin of artery, especially when coronary intervention is to be performed. The authors report a series of these anomalous coronary patients with atherosclerotic disease who underwent transcatheter coronary intervention using Extra Backup left coronary guiding catheters, which help cannulation of the anomalous ostium and enhance the operation success.

Antirestenosis effect of butein in the neointima formation progression

The development of restenosis involves migration and hyperproliferation of vascular smooth muscle cells (VSMCs). Platelet-derived growth factor (PDGF) is one of the major factors. Butein modulates inflammatory pathways and affects the proliferation and invasion of the tumor. We investigated the hypothesis that butein might prevent the restenosis process via a similar pathway. Our results demonstrated that butein inhibited PDGF-induced VSMC proliferation and migration as determined by BrdU proliferation and two-dimensional migration scratch assay. Butein also concentration-dependently repressed PDGF-induced phosphorylation of PDGF-receptor β, mitogen-activated protein kinases, phosphoinositide 3-kinase/Akt, and phopholipase Cγ/c-Src in VSMCs. In addition, in vivo results showed that butein attenuated neointima formation in balloon-injured rat carotid arteries. These results indicate that butein may inhibit PDGF-induced VSMC proliferation and migration, resulting in attenuation of neointima formation after percutaneous transluminal coronary angioplasty. Our study demonstrates for the first time that systemic administration of butein is able to reduce neointima formation after vascular injury.

[Intravascular ultrasound assessment of chitosan/heparin layer-by-layer self assembly coating stent on late stent malapposition and vessel remodeling in porcine model]

OBJECTIVE

To investigate late stent malapposition or vessel remodeling post chitosan/heparin layer-by-layer self assembly coating stent (LBL) implantation in porcine.

METHODS

A total of 32 stents [bare metal stent (BMS, n = 9), sirolimus-eluting stent (SES, n = 11) and LBL (n = 12)] were implanted into coronary arteries of 16 porcine. Intravascular ultrasound (IVUS) was performed immediately after stenting and at 1 month after stenting to measure vessel area (VA), stent area (SA) and lumen area (LA). Neointima area (NA) was measured at 1 month post stenting by IVUS to detect signs of stent malapposition and to determine remodeling index (RI). Histopathology was performed at 1 month post stenting to observe vessel wall structure and stent malapposition status.

RESULTS

No sign of stent malapposition was detected, VA and SA/LA were similar among groups immediately after stent implantation. At 1 month follow-up, none of three groups showed stent malapposition. VA, SA, NA and LA were (7.30 ± 0.77), (6.83 ± 0.76), (1.40 ± 0.96) and (5.43 ± 0.88) mm(2) in LBL group, (7.13 ± 0.69), (6.63 ± 0.71), (0.28 ± 0.35) and (6.34 ± 0.89) mm(2) in SES group, (7.48 ± 0.70), (7.00 ± 0.52), (2.69 ± 1.58) and (4.31 ± 1.28) mm(2) in BMS group. VA and SA were similar among groups (all P > 0.05). LA in LBL group was smaller than SES group (P < 0.01) and significantly larger than in BMS group (P < 0.05).NA in LBL group was larger than SES group (P < 0.01) and significantly smaller than in BMS group (P < 0.05).RI in LBL, SES and BMS groups was 0.95 ± 0.07, 1.02 ± 0.04 and 0.98 ± 0.04 (P > 0.05).

CONCLUSIONS

There is no late stent malapposition or abnormal remodeling post LBL, SES and BMS implantation up to 1 month in this porcine model. LA in LBL group is smaller than SES group and larger than BMS group at 1 month after implantation in this porcine model.

Comparison of coronary flow velocity reserve measurement by transthoracic Doppler echocardiography with 320-row multidetector computed tomographic coronary angiography in the detection of in-stent restenosis in the three major coronary arteries

We sought to compare the diagnostic accuracy and feasibility of coronary flow velocity reserve (CFVR) measurement using transthoracic Doppler echocardiography (TTDE) and 320-row multidetector computed tomographic coronary angiography (CTCA) for predicting in-stent restenosis (ISR). We enrolled 126 consecutive patients with 309 implanted coronary stents in the 3 major coronary arteries. TTDE and CTCA were performed within the 2-week period before follow-up invasive coronary angiography. Binary ISR was defined as percent diameter stenosis ≥50% on invasive coronary angiogram. A CFVR <2.0 using TTDE and a narrowing of ≥50% measured with CTCA were the thresholds indicating the presence of binary ISR. Presence of ISR using invasive coronary angiography was observed in 26 (8%) stents and 26 (14%) vessels. Feasibilities of CFVR measurement and CTCA for predicting ISR in the 3 major vessels were 94% and 91%, respectively. A CFVR <2.0 revealed a 95% diagnostic accuracy with sensitivity of 87%, specificity of 96%, positive predictive value of 77%, and negative predictive value of 98%. Diagnostic accuracy of CTCA was comparable to that of CFVR measurement; however, CTC angiographic results were confounded by metal artifacts in the assessment of small-diameter stents. In conclusion, noninvasive CFVR measurement has high feasibility and accuracy for predicting ISR and is comparable to 320-row CTCA.

[Results of implantation of drug-eluting stents in extensive lesion of the coronary bed according to angiographic and intravascular ultrasound findings]

OBJECTIVE

To study the results after stenting extensive stenoses, the incidence of restenosis according to angiographic findings, as well as changes in endothelization and other morphological parameters in accordance with the data of intravascular ultrasound study (IVUSS).

SUBJECTS AND METHODS

The study included 220 coronary heart disease patients with extensive stenoses of the coronary bed. Double antiaggregant therapy was used in 90% of the patients during the first year and in 9.5% during the second year. Contrast-enhanced coronarography was performed in 174 and 82 patients within the first and second years following stent implantation, respectively. IVUSS was made in 26 patents by the end of the first year and in 24 patients by the end of the second year of a followup. Quantitative and qualitative analyses were done in terms of the following indicators: the mean minimal diameter of a stented segment; its mean minimal area; the number of stents with complete endothelization. RESULTS; In the first year, 1 (0.5%) patient had a fatal outcome; the development of Q-wave and non-Q-wave myocardial infarction (MI) was observed in 2 (1%) and 3 (1.5%) patients, respectively. The appearance of angina symptoms during a year was noted in 10 (4.5%) patients; coronary artery bypass grafting (CABG) was performed in 7 (3.2%) patients; 3 (1.5%) cases had endovascular reintervention. At 2-year follow-up, 6 (2.7%) patients died; 7 (3.2%) and 7 (3.2%) patients developed Q-wave and non-Q-wave MI, respectively; recurrent angina pectoris was noted in 22 (10%) patients. CABG was made in 5 (2.3%) patients; endovascular reintervention was done in 15 (6.9%) patients. The total rate of coronary events was significantly higher at 2-year follow-up (19.2% versus 7.3% at 1-year follow-up). According to coronary angiography, stented segment restenosis was 3.8 and 4.9% after one and two years, respectively. IVUSS showed that the morphological indicators characterizing late vessel luminal loss did not differ between different periods of the follow-up. Complete endothelization was observed only in 40% of endoprostheses a year after stent implantation and in 92% of endoprostheses by the end of the second year (p < 0.05).

CONCLUSION

Complete endothelization was shown by 40 and 91% of the drug-eluting stents by the end of the first and second years of the follow-up, respectively. Within the first year of the follow-up, the total number of coronary events (death + MI + recurrent angina or repeat revascularization) was significantly smaller than that within the second year.

[Intracoronary Stenting and Angiographic Results Strut Thickness Effect on Restenosis Outcome (ISAR-STEREO) Trial]

BACKGROUND

Increased thrombogenicity and smooth muscle cell proliferative response induced by the metal struts compromise the advantages of coronary stenting. The objective of this randomized, multicenter study was to ascertain whether a reduced strut thickness of a stent is associated with improved follow-up angiographic and clinical results.

METHODS AND RESULTS

The study covered 651 patients with stenosis in the native coronary arteries > 2.8 mm in diameter. They were randomly assigned to receive 1 of 2 commercially available stents of comparable design but different thickness: 326 patients to the thin-strut stent (strut thickness of 50 microm) and 325 patients to the thicker-strut stent (strut thickness of 140 microm). The primary end point was the angiographic restenosis (> or = 50% diameter luminal stenosis at follow-up angiography). The secondary end points were the incidence of reinterventions due to restenosis-induced ischemia and the total rate of death and myocardial infarctions at 1 year (a combined end point). The incidence of angiographic restenosis was 15.0% in the thin-strut group and 25.8% in the thick-strut group (relative risk, 0.58; 95% CI, 0.39 to 0.87; p = 0.003). Clinical restenosis was also significantly reduced. Reinterventions were made in 8.6% of the thin-strut patients and in 13.8% of the thick-strut patients (relative risk, 0.62; 95% CI, 0.39 to 0.99; p = 0.03). No difference was observed in the combined 1-year rate of death and myocardial infarction.

CONCLUSIONS

The use of a thin-strut device is associated with a significant reduction of angiographic and clinical restenosis after coronary artery stenting. These findings may have relevant implications for the currently most widely used percutaneous coronary intervention.

Mechanism of edge restenosis after sirolimus-eluting stent implantation

OBJECTIVES

The present study evaluated the mechanism of edge restenosis after sirolimus-eluting stent (SES) implantation using serial (post-intervention and follow-up) intravascular ultrasound (IVUS) analysis.

BACKGROUND

There is little information about the mechanism of edge restenosis after SES implantation.

METHODS

Serial IVUS analysis was performed at 5 mm reference segments immediately proximal and distal to the SES in 25 lesions with edge restenosis. Proximal and distal reference segments were divided into 1 mm subsegments.

RESULTS

Between post-intervention and follow-up IVUS studies, a decrease in external elastic membrane area was observed at the proximal edge. There was a significant increase in plaque & media area in the subsegment closest to the proximal edge. On the other hand, there was an increase in plaque & media area at the distal edge, with no change in external elastic membrane area.

CONCLUSIONS

There may be different mechanisms between proximal and distal edge restenosis after SES implantation. Negative remodeling plays a major role in proximal edge restenosis. On the other hand, intimal hyperplasia may mainly contribute to distal edge restenosis.

Effect of obesity on repeat revascularization in patients undergoing percutaneous coronary intervention with drug-eluting stents

Obesity is a major risk factor for developing coronary artery disease. The impact of obesity on prognosis among those with established coronary disease is less clear. The objective of this study was to evaluate the effect of obesity on repeat revascularization in patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES). We examined 6,083 patients who were divided into three groups according to BMI: normal (BMI 18.5-24.9 kg/m(2), n = 1,592); overweight (BMI 25-29.9 kg/m(2), n = 3,026) and obese (BMI >30 kg/m(2), n = 1,465). The follow-up focused on clinical-driven repeat revascularization, including target lesion revascularization (TLR) and nonTLR. Median follow-up was 26 months (interquartile range 20-32). There was no significant difference in the incidence of TLR among normal, overweight, and obese patients (6.3% vs. 6.1% vs. 7.1%; P = 0.423). In contrast, the incidence of nonTLR was significantly higher in obese patients compared with normal and overweight (8.4% vs. 6.0% vs. 5.8%, P = 0.003). Multivariate analysis showed that obesity was an independent predictor of nonTLR during follow-up (hazard ratio = 1.39; 95% confidence interval = 1.06-1.83; P = 0.019), along with diabetes and hypercholesterolemia. Concomitant use of statins was independently associated with decreased risk of nonTLR (hazard ratio = 0.75; 95% confidence interval = 0.62-0.92; P = 0.005). In conclusion, among patients undergoing PCI with DES, obesity was not associated with TLR, but was associated with a higher risk of nonTLR.

The determinants of side branch compromise after main vessel stenting in coronary bifurcation lesions

BACKGROUND AND AIM

The purpose of this analysis was to determine the factors responsible for side branch (SB) ostial stenosis after main vessel stent implantation.

METHODS

Theoretical and bench-test bifurcation models with different lengths of carina were created. Bench-test experiments with a flexible bifurcation model were performed for the observation of changes in the bifurcation region after stent implantation. An angiographic analysis of 92 bifurcation lesions (84 patients) was performed to determine the role of theoretical parameters on SB compromise in practice. The theoretically predicted and actual SB compromise were compared in these patients.

RESULTS

Bench tests revealed a complex change in the bifurcation region with carina displacement, SB lateral walls stretch and main vessel - SB proximal angle decrease after main vessel stent placement. In an angiographic analysis, actually measured SB% diameter stenosis was larger than expected in 35 (38%) lesions and the measured stenosis was smaller than expected in 49 lesions. Independent predictors of difference between theoretically predicted and observed SB stenosis were carina length mismatch (OR = 2.568, CI 1.336-4.896), main branch reference diameter (OR = 0.314, CI 0.101-0.972), and proximal main vessel - SB angle change after stenting (OR = 0.926, CI 0.870-0.985). In a plot comparing the values of carina length mismatch and deviations from the prediction in SB ostial stenosis, 30% (n = 27) of cases were located in a zone with a shorter carina and more SB compromise than expected, suggesting the role of plaque shift in these cases.

CONCLUSIONS

The degree of SB jailing seems to be determined by carina deformation, the length of the carina, and plaque shifting.

Use of fractional flow reserve in contemporary scenarios of coronary revascularization

Fractional flow reserve (FFR), an invasive pressure-derived index of stenosis severity, can be performed easily, rapidly, and safely in patients with coronary artery disease as a surrogate of non-invasive detection of ischemia. Over the last decades, profound clinical and scientific evaluation has demonstrated that FFR is one of the few diagnostic modalities that improve patient outcome and, at the same time, are cost-effective and cost-saving. The increasing use of PCI to treat multivessel disease and complex anatomical subsets has created new demands for accurate, "per stenosis" assessment, since revascularisation should be performed only in those stenosis that are ischaemia generating. Recent studies have demonstrated that this attitude results in better patient outcomes. Altogether, current evidence clearly supports the measurement of FFR in catheterization laboratories in order to provide objective and complementary data to coronary angiography. The purpose of this review is to discuss the value of FFR in the diagnosis and treatment of patients with different anatomical subsets, including intermediate stenosis, multivessel disease, left main disease, serial stenosis, ostial and bifurcation lesions, saphenous vein graft disease and in-stent restenosis, as well as in those presenting with acute coronary syndromes.

TGF-β and restenosis revisited: a Smad link

Despite novel surgical therapies for the treatment of atherosclerosis, restenosis continues to be a significant impediment to the long-term success of vascular interventions. Transforming growth factor-beta (TGF-β), a family of cytokines found to be up-regulated at sites of arterial injury, has long been implicated in restenosis; a role that has largely been attributed to TGF-β-mediated vascular fibrosis. However, emerging data indicate that the role of TGF-β in intimal thickening and arterial remodeling, the critical components of restenosis, is complex and multidirectional. Recent advancements have clarified the basic signaling pathway of TGF-β, making evident the need to redefine the precise role of this family of cytokines and its primary signaling pathway, Smad, in restenosis. Unraveling TGF-β signaling in intimal thickening and arterial remodeling will pave the way for a clearer understanding of restenosis and the development of innovative pharmacological therapies.

Impact of abciximab in diabetic patients with acute coronary syndrome who undergo percutaneous coronary intervention: results from a high-volume, single-center registry

BACKGROUND

The prevalence of diabetes mellitus (DM) and ischemic heart disease is increasing. Moreover, patients with DM experiencing an acute coronary syndrome (ACS) have an increased risk of adverse outcomes after revascularization compared to non-diabetics. Data have suggested that the glycoprotein IIb/IIIa inhibitor abciximab might be more efficient in diabetics than in those without DM.

METHODS AND RESULTS

We evaluated the effect of abciximab in patients with DM and ACS from our percutaneous coronary intervention (PCI) registry. Among 5,003 patients with ACS who underwent PCI, 629 had DM. Patients were followed for up to 3 years with regard to mortality, myocardial infarction (MI) and target vessel revascularization (TVR). Despite a more severe risk profile, adjusted analyses revealed a marked reduction in TVR (hazard ratio [HR], 0.30; confidence interval [CI], 0.14-0.63; p = 0.002), mortality (HR, 0.53; CI, 0.28-0.97; p = 0.04) and the combined endpoint, also including MI (HR, 0.53; CI, 0.35-0.79; p = 0.002) in the DM patients who received abciximab compared to those who did not, resulting in a risk of reaching the endpoints at levels similar to the risk in patients without DM. The reduction in MI was not significant.

CONCLUSION

Our findings suggest that abciximab administered to ACS patients with DM during PCI reduces mortality and the need for TVR to rates similar to those seen in patients without DM and far below the risk in DM patients who do not receive abciximab.

[The role of micro-RNA/143/145 in evolution of intra-stent restenosis]

The mechanisms of neointima formation and hyperplasia in restenosis remain non-elucidated yet. Because micro-ribonucleic acids/143/145(micro-RNA/143 and micro-RNA/145) participate in the regulation and sustaining of the genotype of mature vascular myocytes we have measured their expression in tissue content of restenoses taken postmortem from 5 patients who underwent angioplasty and subsequently died, and studied its association with actin quantity and fibrillar collagen type I degradation degree. It has been found that during restenosis progression quantity of micro-RNA/143 and micro-RNA/145 decreases in media and intima of coronary artery. This finding has been associated with appearance in coronary intima of coronary myocytes with reduced size likely of secretory phenotype, diminution of number of myocytes with contractile phenotype, and increase of quantity of denaturized collagen type I-phenomena characteristic for neointima hyperplasia, a substrate of intra-stent restenosis.

Towards a self-reporting coronary artery stent--measuring neointimal growth associated with in-stent restenosis using electrical impedance techniques

Implantable medical devices have become the standard method for treating a variety of cardiovascular diseases (NICE, 2003, 2009), such as coronary artery disease, where coronary artery stents are the device of choice (Fischman et al., 1994; Babapulle et al., 2004). One post-operative problem with these devices is the long-term monitoring of the device-tissue interface, with respect to the complications that often arise from in-stent restenosis. This monitoring, where it is available, is currently performed using imaging techniques such as contrast angiography, IVUS, CT and MRI. In this study we propose an alternative method for the non-invasive monitoring of restenosis in coronary artery stents. This preliminary study uses impedance spectroscopy to measure the electrical impedance of cells and tissues associated with the neointimal growth that characterises in-stent restenosis in coronary artery stents. An in vitro organ culture model, using a stent implanted in a section of pig coronary artery, simulated tissue growth inside a stent. Impedance measurements were made regularly over a 28-day culture period. In a novel step, the stent itself was employed as an electrode. Differences in electrical impedance could be seen between control (stent alone) and artery-embedded stents in culture, which were associated with the presence of biological tissue. This method could potentially be developed to produce a stent that was capable of self-reporting in-stent restenosis. The advantages of such a device would be that monitoring could be non-invasively and easily carried out, allowing more routine follow-ups and the early identification and management of any device complications.

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

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

Retrograde recanalization of a chronic ostial occlusion of the left anterior descending artery: how to manage extreme takeoff angles

Chronic total coronary occlusions (CTO) still remain one of the most technically challenging clinical scenearios in which to perform interventions. Although the antegrade approach is the most common method of CTO recanalization, a retrograde attempt improves the success rate and its usagehas been increasingly adopted in the recent years. However, the retrograde method requires exceptional expertise and skills in order to apply a wide variety of strategies, devices and imaging modalities. We report a case of retrograde recanalization of an ostial left anterior descending artery CTO of at least 10 years duration, and discuss some specific issues of a new channel dilating catheter, and practical precautions to keep in mind in the retrograde approach such as the availability of snare technique to facilitate retrograde wire capture and externalization.

Successful retrograde recanalization of a left anterior descending artery chronic total occlusion through a previously placed left anterior descending-to-diagonal artery stent

Since the introduction of the retrograde technique, the success rate of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has increased significantly in patients with suitable anatomy. To our knowledge, retrograde recanalization of a CTO from the abluminal side of a previously placed stent has not been reported. We describe a case of retrograde PCI of a mid left anterior descending (LAD) artery CTO through a previously placed proximal LAD stent which extended into the diagonal artery. The occluded mid LAD was recanalized using the retrograde approach in which retrograde wire crossing into the proximal LAD was successful only after high pressure balloon expansion of the previously placed proximal LAD-to-diagonal stent. Intravascular ultrasound imaging was also used to confirm an intraluminal location of the retrograde guidewire.