Sirolimus and paclitaxel provoke different vascular pathological responses after local delivery in a murine model for restenosis on underlying atherosclerotic arteries

Efficacy and safety of drug-coated balloons in chronic total coronary occlusion recanalization: a systematic review and meta-analysis

BACKGROUND

With advancements in chronic total coronary occlusion (CTO) recanalization techniques and concepts, the success rate of recanalization has been steadily increasing. However, the current data are too limited to draw any reliable conclusions about the efficacy and safety of drug-coated balloons (DCBs) in CTO percutaneous coronary intervention (PCI). Herein, we conducted a meta-analysis to confirm the efficacy of DCB in CTO PCI.

METHODS

We systematically searched PubMed, Web of Science and Embase from inception to July 25, 2023. The primary outcome was major advent cardiovascular events (MACE), including cardiac death, nonfatal myocardial infarction (MI), target lesion revascularization (TLR), and target vessel revascularization (TVR). The follow-up angiographic endpoints were late lumen enlargement (LLE), reocclusion and restenosis.

RESULTS

Five studies with a total of 511 patients were included in the meta-analysis. Across studies, patients were predominantly male (72.9-85.7%) and over fifty years old. The summary estimate rate of MACE was 13.0% (95% CI 10.1%-15.9%, I2 = 0%, p = 0.428). The summary estimate rates of cardiac death and MI were 2.2% (95% CI 0.7%-3.7%, I2 = 0%, p = 0.873) and 1.2% (95% CI -0.2-2.6%, I2 = 13.7%, p = 0.314), respectively. Finally, the pooled incidences of TLR and TVR were 10.1% (95% CI 5.7%-14.5%, I2 = 51.7%, p = 0.082) and 7.1% (95% CI 3.0%-11.2%, I2 = 57.6%, p = 0.070), respectively. Finally, the summary estimate rates of LLE, reocclusion and restenosis were 59.4% (95% CI 53.5-65.3%, I2 = 0%, p = 0.742), 3.3% (95% CI 1.1-5.4%, I2 = 0%, p = 0.865) and 17.5% (95% CI 12.9-22.0%, I2 = 0%, p = 0.623), respectively.

CONCLUSION

Accordingly, DCB has the potential to be used as a treatment for CTO in suitable patients.

First-in-human experience of sirolimus coated balloon for symptomatic intracranial artery stenosis

BACKGROUND

The drug coated balloon is a promising endovascular therapy for intracranial atherosclerosis (ICAS), potentially combining the advantages of primary angioplasty and antiproliferative drugs. Previous studies have focused on the paclitaxel coated balloon, revealing promising outcomes in the treatment of ICAS, while concerns about the neurotoxicity of paclitaxel were reported. Sirolimus was shown to have less neurotoxicity in the canine cerebral vasculature. The feasibility and safety of a sirolimus coated balloon (SCB) for ICAS have never been evaluated in humans. We assessed the first-in-human feasibility and safety of SCBs for treating symptomatic patients with severe ICAS.

METHODS

This prospective, open label, single arm cohort study was designed to enroll patients with transient ischemic attacks or non-disabling, non-perforator territory ischemic stroke caused by severe ICAS (70-99%) and following at least 3 weeks after the onset of ischemic symptoms. The primary outcome was stroke or death within 30 days. All patients were followed up to detect restenosis at 6 months.

RESULTS

A total of 60 eligible patients were enrolled with an average age of 59.4±10.8 years. The technical success rate of SCBs for ICAS was 100%. Seven patients (11.7%) required stenting because of flow limited dissections or elastic retraction. Three patients (5.0%) had 30 day strokes, including two ischemic strokes and one hemorrhagic stroke. An additional three patients had recurrent stroke or death during follow-up. Ten patients had restenosis but only two had symptoms.

CONCLUSIONS

SCBs may be feasible and safe in selected patients with symptomatic ICAS, with high grade stenosis (70-99%). Further studies are warranted.

Drug-Coated Balloon for de-novo Coronary Artery Lesions Exceeding 2.5 mm in Diameter: Optical Coherence Tomography Analysis and Clinical Follow-Up

Objective

To investigate the precise changes in the lumen and lesions, and clinical outcomes after DCB treatment for de-novo coronary lesions exceeding 2.5 mm in diameter through a detailed analysis of OCT.

Methods

This is a prospective study including 53 consecutive patients with 55 de-novo coronary lesions, who underwent DCB angioplasty-only between January 2021 and April 2022. Quantitative coronary angiography (QCA) and OCT were performed before percutaneous coronary interventions (PCI), immediately after PCI, and at 6-9 months follow-up after PCI. Target lesion failure (TLF) was the primary endpoint of the present study. Multivariate logistic regression analysis was performed to identify the predictors or risks for late lumen enlargement (LLE).

Results

A total of 52 patients were successfully treated with DCB. The median follow-up was 7 months, and the incidence of TLF was 7.5%. After the DCB procedure, 43 patients had their scheduled angiographic and OCT examination. QCA demonstrated that the late lumen loss was -0.79 ± 0.28 mm. OCT demonstrated LLE in 79.1% and dissection healing in 65.1% of lesions. After multivariable logistic analysis, type B dissection (odds ratio [OR] 2.92, 95% confidence interval [CI] 1.34-7.41, p = 0.037) was found to be a predictor of LLE, but lipid plaque (OR 0.09, 95% CI 0.01-0.63, p = 0.015) was a risk of LLE.

Conclusion

This is the first and largest prospective study to assess the outcomes of DCB treatment for de-novo coronary lesions exceeding 2.5 mm in diameter and the detection of significant vessel enlargement and dissection healing guide by OCT. DCB could be a novel, safe and effective treatment for de-novo coronary lesions exceeding 2.5 mm in diameter through a detailed analysis of OCT.

The evolution and revolution of drug coated balloons in coronary angioplasty: An up-to-date review of literature data

European Society of Cardiology (ESC) guidelines gave class I A indication for use of DCB in in-stent restenosis. However, no indication exists for the usage of DCB in de novo lesions. Although the current generation DES offer excellent results, as we embark more complex lesions such as calcified lesion and chronic total occlusion, restenosis and stent thrombosis are higher and tend to increase within the years. There is increasing desire to leave nothing behind to abolish the risk of restenosis and stent thrombosis and hence the absorbable scaffolds were introduced, but with disappointing results. In addition, they take several years to be absorbed. Drug coated balloons offer an alternative to stents with no permanent implant of metal or polymer. They are already in use in in Europe and Asia and they have been approved for the first time in the United States for clinical trials specifically for restenotic lesions. There is emerging data in de novo lesions which have shown that DCB are noninferior and in some studies maybe even superior to current generation DES especially in small vessels. In this article, we provide a comprehensive review of the literature on this expanding technology focussing on the evidence in both re-stenotic and de novo lesions.

Pre-clinical investigation of liquid sirolimus for local drug delivery

Introduction

Sirolimus is currently being explored as an alternative drug to paclitaxel for the treatment of peripheral artery disease (PAD). To date, sirolimus has only been used as drug coatings for stents and balloons and no studies have yet demonstrated the delivery of sirolimus in liquid form. The purpose of this pilot study was to investigate the feasibility of the delivery of liquid sirolimus into arterial segments in a benchtop peripheral artery bioreactor.

Methods

The feasibility to deliver liquid therapy was first tested on four drug delivery devices using a fluorescently tagged liquid drug and an ex vivo porcine artery benchtop model. The four devices included the Bullfrog micro-infusion device, ClearWay RX catheter, Occlusion perfusion catheter (OPC), and the targeted adjustable pharmaceutical administration system (TAPAS). Penetration of the fluorescently tagged drug was measured via microscopic imaging and quantification of the depth of drug penetration into all device-treated tissue. Based on the penetration outcome, we then selected a single device to deliver liquid sirolimus into the ex vivo porcine artery model undergoing physiological flow and pressure conditions. The liquid sirolimus-treated arteries were collected from the ex vivo bioreactor at 1- and 24-hour post-delivery and arterial drug retention analyzed by liquid chromatography-tandem mass spectrometry.

Results

Fluorescent microscopy demonstrated that drug delivery with the OPC had greater drug penetration into the medial wall as compared to other devices (OPC: 234 ± 161 µm; TAPAS: 127 ± 68 µm; ClearWay: 118 ± 77 µm; Bullfrog: 2.12 ± 3.78 µm; p = 0.098). The results of the ex vivo flow-circuit bench top model showed that the OPC device successfully delivered the liquid sirolimus at 1-hour (5.17 ± 4.48 ng/mg) and 24-hour (0.78 ± 0.55 ng/mg).

Conclusions

These results demonstrate for the first time the ability to deliver liquid sirolimus directly to the medial layer of an artery via a liquid delivery catheter.

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

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

Intraplaque wiring enables drug-coated balloons to be utilized for percutaneous recanalization of chronically occluded coronary arteries

OBJECTIVES

This study aimed to determine whether drug-coated balloon (DCB) angioplasty following intraplaque wiring and the use of modified balloons is safe and effective in the percutaneous treatment of coronary chronic total occlusions (CTOs).

BACKGROUND

DCB is an alternative therapeutic option without the limitations of permanent vascular implants. However, its efficacy in CTOs has yet to be confirmed. The combination of modified balloons and DCB can be effectively applied when the intraplaque passage of the guidewire is achieved in CTOs.

METHODS

Data from 124 consecutive CTO lesions (105 patients) treated at our hospital between February 2016 and December 2020 were screened for inclusion and retrospectively analyzed. Among the 118 lesions successfully recanalized, intraplaque wiring was achieved in 108, and 85 were treated by the DCB-only approach following cutting/scoring balloon dilatation.

RESULTS

Follow-up data were available for 82 lesions (71 patients). The median occlusion length was 18.5 mm, and the J-CTO score was 1.7 ± 0.9. No in-hospital major adverse cardiac events occurred, including abrupt vessel closure. During the median 29-month follow-up period, target lesion revascularization was performed for 10 lesions. Follow-up coronary angiography (8.7 ± 3.9 months after the index procedure) was performed for 64 lesions, demonstrating late lumen loss of -0.15 mm (interquartile range -0.4 to 0.23 mm), binary restenosis (diameter stenosis ≥50%) in 12 lesions (18.8%), and late lumen enlargement in 37 (57.8%).

CONCLUSION

The DCB-only approach following the use of modified balloons is a promising strategy for coronary CTOs when intraplaque wiring is achieved.

Coronary artery aneurysm formation after paclitaxel-coated balloon-only intervention for de novo coronary chronic total occlusion

Background

Although coronary artery aneurysm (CAA) is an uncommon complication of drug-coated balloon (DCB) treatment, the incidence and mechanisms CAA formation after DCB intervention for chronic total occlusion (CTO) remains to be clarified. The aim of this study was to investigate the incidence of CAA after DCB intervention for the treatment of CTO of coronary arteries.

Materials and methods

This was a retrospective analysis of 82 patients, contributing 88 vessels, who underwent successful DCB-only treatment for de novo CTO lesions. Follow-up angiography was performed in all cases, at a mean 208.5 (interquartile range [IQR]: 174.8 to 337.5) days after the index procedure.

Results

CAA was identified in seven vessels, in seven patients, at the site of previous successful DCB-only treatment. Of these, six were fusiform in shape and one saccular, with a mean diameter of 4.2 ± 1.0 mm and length of 6.7 ± 2.6 mm. Six CAAs developed at the CTO inlet site, and all CAAs occurred at the lesions following dissection immediately after DCB treatment. CAAs were not associated with an increased risk of major clinical events over the median follow-up of 676.5 (IQR: 393.8 to 1,304.8) days.

Conclusion

The incidence of CAA after DCB-only treatment for CTO lesions was 8.0% in this study. Further research is warranted, using intravascular imaging, to clarify the mechanism of DCB-related CAA formation and prognosis.

Monodispersed Sirolimus-Loaded PLGA Microspheres with a Controlled Degree of Drug–Polymer Phase Separation for Drug-Coated Implantable Medical Devices and Subcutaneous Injection

Monodispersed sirolimus (SRL)-loaded poly(lactic-co-glycolic acid) microspheres with a diameter of 1.8, 3.8, and 8.5 μm were produced by high-throughput microfluidic step emulsification—solvent evaporation using single crystal silicon chips consisted of 540–1710 terraced microchannels with a depth of 2, 4, or 5 μm arranged in 10 parallel arrays. Uniform sized droplets were generated over 25 h across all channels. Nearly 15% of the total drug was released by the initial burst release during an accelerated drug release testing performed at 37 °C using a hydrotropic solution containing 5.8 M N,N-diethylnicotinamide. After 24 h, 71% of the drug was still entrapped in the particles. The internal morphology of microspheres was investigated by fluorescence microscopy using Nile red as a selective fluorescent stain with higher binding affinity toward SRL. By increasing the drug loading from 33 to 50 wt %, the particle morphology evolved from homogeneous microspheres, in which the drug and polymer were perfectly mixed, to patchy particles, with amorphous drug patches embedded within a polymer matrix to anisotropic patchy Janus particles. Janus particles with fully segregated drug and polymer regions were achieved by pre-saturating the aqueous phase with the organic solvent, which decreased the rate of solvent evaporation and allowed enough time for complete phase separation. This approach to manufacturing drug-loaded monodisperse microparticles can enable the development of more effective implantable drug-delivery devices and improved methods for subcutaneous drug administration, which can lead to better therapeutic treatments.

Impact of late lumen loss on clinical outcomes of side branch bifurcation lesions treated by drug-coated balloon angioplasty with main branch stenting

BACKGROUND

Drug-coated balloon (DCB) angioplasty for side branches with main branch stenting is effective for bifurcation lesions and reduces late lumen loss (LLL) in side branches. However, the predictors and clinical implications of LLL after DCB angioplasty are largely unexplored.

METHODS

Among 181 patients undergoing DCB angioplasty for side branches with drug-eluting stent implantation for main branches between 2016 and 2018, we enrolled 138 patients (138 lesions) undergoing follow-up coronary angiography within 1 year. The 1-year cumulative rates of target lesion revascularization (TLR) and major adverse cardiac events (MACE: defined as a composite of all-cause death, myocardial infarction, and TLR) were compared between patients with late lumen gain (LLG) (LLG group) and those with LLL (LLL group).

RESULTS

The binary restenosis rate of the side branch was 8.0% (11 lesions), mean LLL was -0.14 ± 0.43 mm, and LLG was observed in 99 lesions (71.7%). The DCB size/reference vessel diameter ratio showed mild discrimination (area under the curve, 0.60; 95% confidence interval, 1.2-65.0; p = 0.03) for predicting the side branch progression. The 1-year cumulative rates of MACE and TLR were not significantly different but numerically lower in the LLG group than in the LLL group (2.0% vs. 7.8%, p = 0.11 and 2.0% vs. 7.7%, p = 0.11, respectively). Lumen regression after DCB angioplasty for side branches are associated with improved clinical outcomes.

CONCLUSIONS

The DCB size relative to the reference vessel diameter is a predictor of late lumen enlargement in side branches.

Application of drug-coated balloons for intracranial atherosclerosis disease: a systematic review

BACKGROUND

Although percutaneous transluminal angioplasty and stenting (PTAS) was an effective and safe alternative treatment for severe intracranial atherosclerosis disease (ICAD), the high rate of restenosis remained a major issue for this endovascular procedure. Recently, the application of drug-coated balloons (DCB) in ICAD was developed to reduce restenosis. This systematic review aimed to evaluate the efficacy and safety of DCB angioplasty for ICAD.

METHODS

We searched relevant databases for eligible studies enrolling ICAD patients treated with DCB. The event rates of restenosis and periprocedural complications in the follow-up period were pooled with random-/fixed-effect models using Freeman-Tukey double arcsine transformation. Heterogeneity tests and publication bias tests were performed.

RESULTS

Two hundred and twenty-four ICAD patients treated with DCB from 9 eligible studies were included. Rate of stenosis in the DCB arm before treatment was ranged from 62% to 90% and reported median follow-up was ranged from 3 to 10.7 months. The pooled incidence of restenosis were 5.7% (95% confidence interval [CI] 2.6%-9.7%; I² = 0%, p = 0.516) and 5.9% for periprocedural complications (95% CI: 2.5-10.3%; I² = 0%, p = 0.649) in follow-up term.

CONCLUSION

With the limitation of the low quality of the available evidence, angioplasty with DCB appears to be effective and safe in severe ICAD. Further larger randomized trials are needed to provide more definitive evidence and to address the ideal clinical context for their application.

Myostatin Inhibits Vascular Smooth Muscle Cell Proliferation and Local 14q32 microRNA Expression, But Not Systemic Inflammation or Restenosis

Myostatin is a negative regulator of muscle cell growth and proliferation. Furthermore, myostatin directly affects the expression of 14q32 microRNAs by binding the 14q32 locus. Direct inhibition of 14q32 microRNA miR-495-3p decreased postinterventional restenosis via inhibition of both vascular smooth muscle cell (VSMC) proliferation and local inflammation. Here, we aimed to investigate the effects of myostatin in a mouse model for postinterventional restenosis. In VSMCs in vitro, myostatin led to the dose-specific downregulation of 14q32 microRNAs miR-433-3p, miR-494-3p, and miR-495-3p. VSMC proliferation was inhibited, where cell migration and viability remained unaffected. In a murine postinterventional restenosis model, myostatin infusion did not decrease restenosis, neointimal area, or lumen stenosis. Myostatin inhibited expression of both proliferation marker PCNA and of 14q32 microRNAs miR-433-3p, miR-494-3p, and miR-495-3p dose-specifically in cuffed femoral arteries. However, 14q32 microRNA expression remained unaffected in macrophages and macrophage activation as well as macrophage influx into lesions were not decreased. In conclusion, myostatin did not affect postinterventional restenosis. Although myostatin inhibits 14q32 microRNA expression and proliferation in VSMCs, myostatin had no effect on macrophage activation and infiltration. Our findings underline that restenosis is driven by both VSMC proliferation and local inflammation. Targeting only one of these components is insufficient to prevent restenosis.

Positive Vessel Remodelling

Since its introduction, the success of percutaneous transluminal coronary angioplasty (PTCA) has been jeopardised by recoil, neointima proliferation, and luminal renarrowing; however, the benefit of positive remodelling has not gained widespread attention. While vessels will remodel positively up to a certain stage in the development of atherosclerosis, the therapeutic application of this process remains low. The prevention of vessel shrinkage during the healing process, which represents the predominant mechanism of restenosis after PTCA, is a prerequisite of long-term success in PTCA. The antiproliferative drugs that are currently used mainly on stents are known to be capable of this. Primary clinical studies have reported that positive remodelling leads to beneficial effects in coronary and peripheral angioplasty if no foreign body is inserted, and a paradigm change in percutaneous coronary intervention towards far fewer implants is within reach.

Diagnosis, classification, and treatment of femoropopliteal artery in-stent restenosis

In-stent restenosis is a pervasive challenge to the durability of stenting for the treatment of lower extremity ischemia. There is considerable controversy about the criteria for diagnosis, indications for treatment, and preferred algorithm for addressing in-stent restenosis. This evidence summary seeks to review existing information on strategies for the treatment of this difficult problem.

A Biodegradable Microneedle Cuff for Comparison of Drug Effects through Perivascular Delivery to Balloon-Injured Arteries

Restenosis at a vascular anastomosis site is a major cause of graft failure and is difficult to prevent by conventional treatment. Perivascular drug delivery has advantages as drugs can be diffused to tunica media and subintima while minimizing the direct effect on endothelium. This in vivo study investigated the comparative effectiveness of paclitaxel, sirolimus, and sunitinib using a perivascular biodegradable microneedle cuff. A total of 31 New Zealand white rabbits were used. Rhodamine was used to visualize drug distribution (n = 3). Sirolimus- (n = 7), sunitinib- (n = 7), and paclitaxel-loaded (n = 7) microneedle cuffs were placed at balloon-injured abdominal aortae and compared to drug-free cuffs (n = 7). Basic histological structures were not affected by microneedle devices, and vascular wall thickness of the device-only group was similar to that of normal artery. Quantitative analysis revealed significantly decreased neointima formation in all drug-treated groups (p < 0.001). However, the tunica media layer of the paclitaxel-treated group was significantly thinner than that of other groups and also showed the highest apoptotic ratio (p < 0.001). Proliferating cell nuclear antigen (PCNA)-positive cells were significantly reduced in all drug-treated groups. Sirolimus or sunitinib appeared to be more appropriate for microneedle devices capable of slow drug release because vascular wall thickness was minimally affected.

A chemical stability study of trimethylsilane plasma nanocoatings for coronary stents

Trimethylsilane (TMS) plasma nanocoatings were deposited onto stainless steel coupons in direct current (DC) and radio frequency (RF) glow discharges and additional NH₃/O₂ plasma treatment to tailor the coating surface properties. The chemical stability of the nanocoatings were evaluated after 12 week storage under dry condition (25 °C) and immersion in simulated body fluid (SBF) at 37 °C. It was found that nanocoatings did not impact surface roughness of underlying stainless steel substrates. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were used to characterize surface chemistry and compositions. Both DC and RF nanocoatings had Si- and C-rich composition; and the O- and N-contents on the surfaces were substantially increased after NH₃/O₂ plasma treatment. Contact angle measurements showed that DC-TMS nanocoating with NH₃/O₂ treatment generated very hydrophilic surfaces. DC-TMS nanocoatings with NH₃/O₂ treatment showed minimal surface chemistry change after 12 week immersion in SBF. However, nitrogen functionalities on RF-TMS coating with NH₃/O₂ post treatment were not as stable as in DC case. Cell culture studies revealed that the surfaces with DC coating and NH₃/O₂ post treatment demonstrated substantially improved proliferation of endothelial cells over the 12 week storage period at both dry and wet conditions, as compared to other coated surfaces. Therefore, DC nanocoatings with NH₃/O₂ post treatment may be chemically stable for long-term properties, including shelf-life storage and exposure to the bloodstream for coronary stent applications.

Treatment of chronic total occlusions in native coronary arteries by drug-coated balloons without stenting - A feasibility and safety study

BACKGROUND

Chronic total occlusions remain one of the biggest challenges for interventional cardiologists and the high risk of restenosis and stent thrombosis is still a major problem. Drug-coated balloons showed favorable results for the treatment of in-stent restenosis and other lesion types. The aim of this study was to evaluate the feasibility and outcome of a drug-coated balloon only approach for chronic total occlusion.

METHODS

We included 34 patients with a native chronic total occlusion treated only by drug-coated balloons. A visual residual stenosis of 30% or less without major dissection was considered a satisfactory percutaneous intervention result according to the German Consensus Group recommendations for drug-coated balloon use. We collected clinical and procedural data. Angiograms were conducted during the procedure and at follow-up. Quantitative coronary analysis was performed and mean and minimal lumen diameter and late luminal changes were assessed.

RESULTS

The recanalization was considered satisfactory in 79.4% (n=27). Restenosis occurred in 11.8% (n=4) and reocclusion in 5.9% (n=2). Out of the 27 patients with a satisfactory initial result, 3.7% (n=1) had reocclusion and 3.7% (n=1) had restenosis. In the subgroup without satisfactory result (n=7), restenosis occurred in 3 patients (42.9%) and reocclusion in 1 patient (14.3%). A luminal increase was found in 67.6% (n=23) and mean late luminal gain was 0.11±0.49mm. Angina class improved significantly (p<0.001). There was no death or myocardial infarction.

CONCLUSIONS

Drug-coated balloon angioplasty without stenting is a feasible and well-tolerated treatment method for chronic total occlusions if the predilatation result is good.

Fractional flow reserve-guided coronary angioplasty using paclitaxel-coated balloons without stent implantation: feasibility, safety and 6-month results by angiography and optical coherence tomography

Background

Percutaneous coronary interventions (PCI) with drug-coated balloons (DCB) might be a promising trade-off between balloon angioplasty and drug-eluting stents, since DCB inhibit neointimal proliferation and limit duration of dual antiplatelet therapy. We investigated the safety, feasibility, and 6-month results of fractional flow reserve (FFR)-guided use of the paclitaxel-coated SeQuent Please^® balloon without stenting for elective PCI of de novo lesions.

Methods and results

In 46 patients (54 lesions) with stable symptomatic coronary artery disease (CAD), a FFR-guided POBA (plain old balloon angioplasty) was performed. In case of a sufficient POBA result with residual stenosis < 40 %, FFR > 0.8 and no severe dissection, the target lesion was finally dilated using the DCB. Quantitative coronary angiography (QCA) was performed before and after the index procedure and at 6-month follow-up (f/u) to calculate late lumen loss (LLL) and net luminal gain (NLG). Optical coherence tomography (OCT) was performed at f/u to assess vascular remodeling. DCB-only treatment was applied to 43 patients (51 lesions), while 3 patients (3 lesions) needed provisional stenting. Invasive f/u was completed in 39 patients (47 lesions). At the stenotic site, the lumen diameter showed a trend toward progressive increase at f/u (LLL: −0.13 ± 0.44 mm, n.s.; NLG: 1.10 ± 0.53 mm, p < 0.001) without aneurysm formation or restenosis after DCB-only treatment.

Conclusions

FFR-guided DCB-only PCI of de novo lesions appeared feasible and safe in stable CAD with clopidogrel discontinuation after 4 weeks, showing a trend toward positive vessel remodeling without lumen loss at 6 months.

Clinical trial registration http://www.clinicaltrials.gov. Unique identifier: NCT02120859

Electronic supplementary material

The online version of this article (doi:10.1007/s00392-016-1019-4) contains supplementary material, which is available to authorized users.

Serial Morphological Changes of Side-Branch Ostium after Paclitaxel-Coated Balloon Treatment of De Novo Coronary Lesions of Main Vessels

PURPOSE

The effects on the side-branch (SB) ostium, following paclitaxel-coated balloon (PCB) treatment of de novo coronary lesions of main vessels have not been previously investigated. This study was aimed at evaluating the serial morphological changes of the SB ostium after PCB treatment of de novo coronary lesions of main vessels using optical coherence tomography (OCT).

MATERIALS AND METHODS

This prospective, single-center observational study enrolled patients with de novo lesions, which were traversed by at least one SB (≥1.5 mm) and were treated with PCB. The SB ostium was evaluated with serial angiographic and OCT assessments pre- and post-procedure, and at 9-months follow-up.

RESULTS

Sixteen main vessel lesions were successfully treated with PCB, and 26 SBs were included for analysis. Mean SB ostial lumen area increased at 9-months follow-up (0.92±0.68 mm² pre-procedure, 1.03±0.77 mm² post-procedure and 1.42±1.18 mm² at 9-months). The SB ostial lumen area gain was 0.02±0.24 mm² between pre- and post-procedure, 0.37±0.64 mm² between post-procedure and 9-months, and 0.60±0.93 mm² between pre-procedure and 9-months. The ostial lumen area increased by 3.9% [interquartile range (IQR) of -33.3 to 10.4%] between pre- and post-procedure, 52.1% (IQR of -0.7 to 77.3%) between post-procedure and 9-months and 76.1% (IQR of 18.2 to 86.6%) between pre-procedure and 9-months.

CONCLUSION

PCB treatment of de novo coronary lesions of main vessels resulted in an increase in the SB ostial lumen area at 9-months.

Comparison of Paclitaxel-Coated Balloon Treatment and Plain Old Balloon Angioplasty for De Novo Coronary Lesions

PURPOSE

This study compared the angiographic outcomes of paclitaxel-coated balloon (PCB) versus plain old balloon angioplasty (POBA) treatment for de novo coronary artery lesions. At present, there is no available data comparing the efficacy of PCB versus POBA for the treatment of de novo coronary lesions.

MATERIALS AND METHODS

This multicenter retrospective observational study enrolled patients with de novo coronary lesions with a reference vessel diameter between 2.5 mm and 3.0 mm and lesion length ≤ 24 mm who were successfully treated with PCB or POBA. Angiographic measurements and quantitative coronary analysis were performed before and after the procedure, and at 9 months follow-up.

RESULTS

A total of 72 patients (49 receiving PCB and 23 receiving POBA) were enrolled in this study. Late luminal loss was -0.12 ± 0.30 mm in the PCB group and 0.25 ± 0.50 mm in the POBA group (p<0.001). There was a higher percentage of binary restenosis (diameter stenosis ≥ 50%) in POBA, compared to PCB (30.4%, n=7 vs. 4.1%, n=2, p<0.001). Target vessel revascularization was higher in the POBA group (13.0%, n=3 vs. 0%, p=0.033).

CONCLUSION

PCB treatment of de novo coronary lesions showed better 9-month angiographic outcomes than POBA treatment alone.

Gold nanorods as a theranostic platform for in vitro and in vivo imaging and photothermal therapy of inflammatory macrophages

Inflammatory macrophages play pivotal roles in the development of atherosclerosis. Theranostics, a promising approach for local imaging and photothermal therapy of inflammatory macrophages, has drawn increasing attention in biomedical research. In this study, gold nanorods (Au NRs) were synthesized, and their in vitro photothermal effects on the macrophage cell line (Ana-1 cells) under 808 nm near infrared reflection (NIR) were investigated by the CCK8 assay, calcein AM/PI staining, flow cytometry, transmission electron microscopy (TEM), silver staining and in vitro micro-computed tomography (CT) imaging. These Au NRs were then applied to an apolipoprotein E knockout (Apo E) mouse model to evaluate their effects on in vivo CT imaging and their effectiveness as for the subsequent photothermal therapy of macrophages in femoral artery restenosis under 808 nm laser irradiation. In vitro photothermal ablation treatment using Au NRs exhibited a significant cell-killing efficacy of macrophages, even at relatively low concentrations of Au NRs and low NIR powers. In addition, the in vivo results demonstrated that the Au NRs are effective for in vivo imaging and photothermal therapy of inflammatory macrophages in femoral artery restenosis. This study shows that Au nanorods are a promising theranostic platform for the diagnosis and photothermal therapy of inflammation-associated diseases.

Pharmacokinetic Study of Paclitaxel Concentration after Drug-Eluting Balloon Angioplasty in the Iliac Artery of Healthy and Atherosclerotic Rabbit Models

PURPOSE

To assess whether the presence of an atherosclerotic lesion may alter the deposition kinetics of paclitaxel on the arterial wall after drug-eluting balloon (DEB) angioplasty, as well as paclitaxel concentrations in serum and in the recovered balloons.

MATERIALS AND METHODS

Three New Zealand White rabbit models were created: an atheroma group (arterial mechanical injury and hyperlipidic diet; group A), a prelesional group (fat arterial infiltration, hyperlipidic diet; group B), and a control healthy group (group C). Forty-five animals underwent DEB angioplasty in the iliac artery. Arteries and serum samples were analyzed by liquid chromatography/tandem mass spectrometry at 1, 24, 48, 72, and 96 hours (arteries) and at 1, 6, 12, and 24 hours (serum). Recovered balloons were analyzed by UV chromatography. Histologic and statistical analyses were also performed.

RESULTS

Group A showed significantly higher arterial paclitaxel concentrations in the first hour after DEB angioplasty (632.05 ng/mg ± 125.75 in group A vs 179.55 ng/mg ± 45.64 and 168.54 ng/mg ± 83.48 in groups B and C, respectively; P < .05). Paclitaxel was undetectable in serum at 24 hours in all groups, but the amount was significantly higher (P < .05) in group B at 1, 6, and 12 hours. The paclitaxel amount in navigated balloons from group A was significantly lower than in other groups (P < .05).

CONCLUSIONS

Paclitaxel concentration in an atherosclerotic lesion model immediately after DEB angioplasty is nearly fourfold higher than in a healthy artery. Paclitaxel remains in the bloodstream longer when a universal state of fat arterial infiltration is achieved. These findings could have clinical implications, as studies testing commercial drug-eluting devices on healthy animals may be underestimating paclitaxel arterial uptake.

Targeting PI3Kγ activity decreases vascular trauma-induced intimal hyperplasia through modulation of the Th1 response

Interventional strategies to treat atherosclerosis, such as transluminal angioplasty and stent implantation, often cause vascular injury. This leads to intimal hyperplasia (IH) formation that induces inflammatory and fibroproliferative processes and ultimately restenosis. We show that phosphoinositide 3-kinase γ (PI3Kγ) is a key player in IH formation and is a valid therapeutic target in its prevention/treatment. PI3Kγ-deficient mice and mice expressing catalytically inactive PI3Kγ (PI3Kγ KD) showed reduced arterial occlusion and accumulation of monocytes and T cells around sites of vascular lesion. The transfer of PI3Kγ KD CD4(+) T cells into Rag2-deficient mice greatly reduced vascular occlusion compared with WT cells, clearly demonstrating the involvement of PI3Kγ in CD4(+) T cells during IH formation. In addition we found that IH is associated with increased levels of Th1 and Th17 cytokines. A specific decrease in the Th1 response was observed in the absence of PI3Kγ activity, leading to decreased CXCL10 and RANTES production by smooth muscle cells. Finally, we show that treatment with the PI3Kγ inhibitor AS-605240 is sufficient to decrease IH in both mouse and rat models, reinforcing the therapeutic potential of PI3Kγ inhibition. Altogether, these findings demonstrate a new role for PI3Kγ activity in Th1-controlled IH development.

Perivascular biodegradable microneedle cuff for reduction of neointima formation after vascular injury

Restenosis often occurs at the site of vascular grafting and may become fatal for patients. Restenosis at anastomosis sites is due to neointimal hyperplasia (NH) and difficult to treat with conventional treatments. Such abnormal growth of smooth muscle cells in tunica media of vascular tissue can be reduced by delivering anti-proliferation drugs such as paclitaxel (PTX) to the inner vascular layer. Drug eluting stents (DES) or drug eluting balloon (DEB) have been developed to treat such vascular diseases. However, they are less efficient in drug delivery due to the drug loss to blood stream and inadequate to be applied to re-stenotic area in the presence of stent or anastomosis sites. Recently, we have introduced microneedle cuff (MNC) as perivascular delivery devices to achieve high delivery efficiency to tunica media. In this study, we investigated in vivo microneedle insertion and efficacy in treating NH using a rabbit balloon injury model. Microneedle shape was optimized for reliable insertion into tunica media layer. Uniform distribution of PTX in tunica media delivered by MNC devices was also confirmed. Animal study demonstrated significant NH reduction by MNC treatments and much higher delivery efficiency than flat type devices.

Critical evaluation of stents in the peripheral arterial disease of the superficial femoral artery - focus on the paclitaxel eluting stent

The endovascular management of obstructive disease of the superficial femoral artery (SFA) is challenging due to unique anatomical and biomechanical forces. Obstructive lesions of the SFA make up the largest proportion of lesions leading to symptomatic peripheral arterial disease. Accordingly, endovascular treatment of SFA disease is becoming increasingly common and, in many cases, is the preferred initial therapy. The use of self-expanding nitinol stents have proven superior to percutaneous transluminal balloon angioplasty in the treatment of intermediate length SFA stenosis. However, achieving durable results, as well as attaining adequate therapy for long occlusions typically seen in clinical practice, remains problematic. Newer technologies, such as paclitaxel eluting stents, seem promising in improving outcomes.

Paclitaxel: new uses for an old drug

Paclitaxel (Taxol), one of the most important anticancer drugs, has been used for therapy of different types of cancers. Mechanistically, paclitaxel arrests cell cycle and induces cell death by stabilizing microtubules and interfering with microtubule disassembly in cell division. Recently, it has been found that low-dose paclitaxel seems promising in treating non-cancer diseases, such as skin disorders, renal and hepatic fibrosis, inflammation, axon regeneration, limb salvage, and coronary artery restenosis. Future studies need to understand the mechanisms underlying these effects in order to design therapies with specificity.

No indication for an unexpected high rate of coronary artery aneurysms after angioplasty with drug-coated balloons

AIMS

Coronary artery aneurysms (CAA) are a rare complication after percutaneous coronary intervention (PCI) and are reported with an incidence of 0.6% to 3.9%. While in recent years the use of paclitaxel drug-coated balloons (DCB) has increased, so far no CAA formation after DCB intervention has been reported.

METHODS AND RESULTS

During the years 2010 and 2011 we used DCBs in 704 PCIs. Follow-up angiography was scheduled at four months in all patients and has so far been achieved in 380 PCIs. In three patients we found development of a CAA at the former PCI site within four months of observation. Aneurysm length varied between 8.4 mm and 13 mm and lumina increased 58% to 131%. Retrospectively all patients with CAA development showed small intimal dissection partially with tiny persisting contrast bands parallel to the lumen according to type B and type C of the NHLBI classification after PCI.

CONCLUSIONS

CAA formation after DCB intervention was found in three out of 380 PCIs with DCB, consistent with an incidence of 0.8%. Thus, PCI with DCB does not cause an unexpectedly high rate of coronary artery aneurysms.

Enhancement of osteosarcoma cell sensitivity to cisplatin using paclitaxel in the presence of hyperthermia

PURPOSE

This paper aimed to evaluate the effects of a combination of paclitaxel and cisplatin on osteosarcoma (OS) cell lines in the presence of hyperthermia and to investigate the related mechanism.

MATERIALS AND METHODS

Two types of OS cell lines (OS732 and MG63) were treated with paclitaxel and cisplatin in the presence of hyperthermia. The survival rate was measured by MTT assay, and the clonogenic rate was measured by a clonogenic assay. The cellular changes were observed with an inverted phase contrast microscope and a fluorescence microscope. The apoptotic effect was analysed with flow cytometry (FCM). Fas expression by the OS cell lines was measured by western blot. Fas expression in OS tissue was measured by immunohistochemistry.

RESULTS

Our study indicated that 1 h after the application of a combination of 10 μg/mL paclitaxel and 5 μg/mL cisplatin to OS cells at 43 °C, the survival rate of the OS cells was 11.96%, which was significantly lower than when either 10 μg/mL paclitaxel (45.02%) or 5 μg/mL cisplatin (48.69%) was applied alone (p < 0.01). Additionally, the clonogenic assay demonstrated that the clonogenic survival rate in the OS cells of the combination group was lower than that in the individual groups. Moreover, the cellular changes and apoptosis rates indicated that apoptosis in the combined application group was much greater than when either drug was applied individually. Fas expression by OS cell lines was increased by the combination of paclitaxel and cisplatin under hyperthermic conditions. More importantly, our study revealed low Fas expression in OS, which better explained the up-regulation of Fas achieved by the combination of paclitaxel and cisplatin in the presence of hyperthermia.

CONCLUSIONS

The combination of paclitaxel and cisplatin increases the effects of thermochemotherapy on OS cell lines, primarily through the induction of apoptosis by the up-regulation of Fas expression.

The effect of short-term intra-arterial delivery of paclitaxel on neointimal hyperplasia and the local thrombotic environment after angioplasty

PURPOSE

To evaluate the effects of short-term intra-arterial delivery of paclitaxel on neointimal hyperplasia and the local thrombotic environment after angioplasty.

METHODS

An experimental common carotid artery injury model was established in 60 rats, which were divided into experimental groups (40 rats) and controls (20 rats). Local intra-arterial administration of paclitaxel was applied at 2 doses (90 and 180 μg/30 μl), and the effects of short-term delivery of paclitaxel on neointimal hyperplasia and the expression of tissue factor (TF), plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (t-PA) were evaluated at days 15 and 30 by hematoxylin and eosin staining and immunohistochemistry.

RESULTS

At 15 and 30 days after injury, neointimal thickness and area, the ratio of intimal area to medial area and the stenotic rate were all significantly decreased in the group provided the high concentrations (180 μg/30 μl) of paclitaxel for 2 min or 10 min and in the group provided the low concentration (90 μg/30 μl) of paclitaxel for 10 min (p < 0.05). At 30 days after injury, there were no significant changes in TF expression among all experimental groups. PAI-1 expression increased in the neointima of the high concentration 10 min group (p < 0.05), while t-PA expression decreased in the neointima of the high concentration 2 min group (p < 0.05).

CONCLUSION

In the rat common carotid artery injury model, the short-term delivery of paclitaxel could effectively inhibit neointimal hyperplasia in the long term, with very little influence on the local expression of TF and PAI-1.

Synergistic increase in the sensitivity of osteosarcoma cells to thermochemotherapy with combination of paclitaxel and etoposide

Osteosarcoma is a malignant bone tumor which is found most commonly in adolescents and young adults. Local perfusion thermochemotherapy has long been proposed as an alternative strategy for the treatment of osteosarcoma. As a standard anticancer drug, paclitaxel plays a significant role in the treatment of a number of tumors; however, little is known concerning its ability to promote thermochemotherapy. The aim of this study was to evaluate the cytotoxic effects of a combination of paclitaxel and etoposide on an osteosarcoma cell line in the presence of hyperthermia and to investigate the related mechanism. Our study indicated that 1 h after the application of a combination of 10 µg/ml paclitaxel and 5 µg/ml etoposide to OS732 cells at 43˚C, the survival rate of the cells was 14.52% which was significantly lower than when either 10 µg/ml paclitaxel (45.83%) or 5 µg/ml etoposide (43.31%) was applied alone (P<0.01). Moreover, changes in cellular morphology and apoptotic rates indicated that the apoptosis-inducing effect of the combination was much stronger than that of either drug applied individually. Fas expression levels in the OS732 cells were increased by the combination of paclitaxel and etoposide in the presence of hyperthermia. Therefore, paclitaxel enhances the thermochemotherapy of the osteosarcoma cell line and this is primarily accomplished by the upregulation of Fas expression and the induction of apoptosis.

Induction of apoptosis by a combination of paclitaxel and carboplatin in the presence of hyperthermia

PURPOSE

To study enhancing effects of paclitaxel in the thermochemotherapy of osteosarcoma cell lines and related mechanisms.

MATERIALS AND METHODS

Paclitaxel and carboplatin were used alone or jointly on OS732 cell lines in the presence of hyperthermia. Inhibition of proliferation was measured by MTT assay and cellular changes were assessed with inverted phase contrast and fluorescence microscopy. Apoptosis was analyzed with flow cytometry (FCM) and Fas expression by immunocytochemistry.

RESULTS

At 43 degrees C, one hour after the application of 10 μg/ml paclitaxel and 5 μg/ml carboplatin on OS732 cells jointly, the survival rate was 15.8% which was significantly lower than with 10 μg/ml paclitaxel (45.8%) and 5 μg/ml carboplatin (47.7%) respectively (P<0.01). Moreover, changes of morphology and apoptotic rates indicated that the apoptosis-inducing effect of combined application was also much enhanced, as evident also regarding Fas expression.

CONCLUSION

Paclitaxel is conducive to thermochemotherapy of osteosarcoma cell lines, possibly accomplished by up-regulation of Fas expression with induction of apoptosis.

Below-the-knee drug-eluting stents and drug-coated balloons

Endovascular procedures have evolved to the mainstream treatment of choice for revascularization of infrapopliteal obstructive disease, especially in patients suffering from critical limb ischemia and multiple comorbidities. However, standard balloon angioplasty is limited by the potential of a suboptimal acute outcome due to elastic recoil and/or flow-limiting dissection, followed by neointimal hyperplasia and progressive vascular restenosis even in the case of bare-metal stent use. Drug-eluting stents and drug-coated balloons are emerging endovascular technologies with the promise of significant inhibition of vessel restenosis and improved clinical outcomes. The current review outlines the drug-eluting properties of those instruments and summarizes the currently available clinical data. The authors critically appraise the current status and also provide a glimpse of the near future of endovascular below-the-knee treatments.

Restenosis after PCI. Part 2: prevention and therapy

The techniques and materials used during percutaneous coronary intervention have advanced considerably over the past 3 decades, yet restenosis remains one of the major drawbacks of this procedure. Many innovative technologies, including drug-eluting stents, with or without specific polymers, and fully biodegradable stents have been and continue to be developed in the search for a safe and effective antirestenosis therapy. Remarkable advances in stent design and nanoparticle delivery systems ('nanovehicles') have already fueled revolutionary changes in the prevention and treatment of in-stent restenosis. In this Review we provide an overview of the latest innovations for optimizing outcomes of coronary stenting, and up-to-date information about prevention and treatment of in-stent restenosis.

Downstream coronary effects of drug-eluting stents

BACKGROUND

Antiproliferative agents used in drug-eluting stents (DES) attenuate atherosclerosis, yet DES implantation has been linked to endothelial dysfunction. The downstream effects of DES on new lesion formation have not been previously directly examined. We sought to compare the development of de novo stenoses and need for treatment in the downstream coronary vessel of patients treated with DES or a bare-metal stent.

METHODS

Angiographic images and procedural information were prospectively collected on 463 adults who underwent implantation of a single stent in a proximal coronary artery, had an appropriate control vessel for comparison, and subsequently returned for intervention. Propensity matching identified 89 pairs of patients. End points were defined as angiographic identification of a de novo stenosis or need for secondary intervention in the downstream vessel within 12 months of initial intervention.

RESULTS

In the overall (P < .01) and propensity-matched cohort (P = .01), there was reduced risk of new lesions downstream to DES. No difference was seen in respective control vessels (P = .14 and P = .99). A reduced need for downstream intervention with DES was seen in both the overall (P = .01) and propensity-matched cohorts (P = .04). No difference was seen in the control vessels (P = .98 and P = .36). Multivariate proportional hazards modeling of known atherosclerosis risk factors identified stent type as the sole predictor for downstream lesions (P < .01) and downstream events (P = .02).

CONCLUSIONS

Patients receiving DES appear less likely to develop downstream stenoses and events compared with patients receiving bare-metal stents, suggesting beneficial downstream drug delivery.

Correlation of tissue drug concentrations with in vivo magnetic resonance images of polymer drug depot around arteriovenous graft

Sustained delivery of anti-proliferative drugs to the perivascular area using an injectable polymeric platform is a strategy to inhibit vascular hyperplasia and stenosis. In this study, the concentrations of sirolimus in vascular tissues were evaluated after delivery using an injectable platform made of poly(lactic-co-glycolic acid)-polyethylene glycol-poly(lactic-co-glycolic acid) (PLGA-PEG-PLGA). In order to optimize the drug release profile, the effect of two solvents or solid loading of the sirolimus into the polymer gel was first examined in vitro. The early release was slower with loading of dry drug into the polymer, compared to drug dissolution in solvents. Dry sirolimus was therefore used to load the polymer and applied to the perivascular surface of the graft-venous anastomosis at the time of surgical placement of a carotid-jugular synthetic hemodialysis graft in a porcine model. This was replenished by ultrasound-guided injection of additional drug-laden polymer at one, two and three weeks post-operatively. Magnetic resonance imaging (MRI) using pulse sequences specifically designed for optimal detection of the polymeric gel showed that the polymer injected post-operatively remained at the juxta-anastomotic perivascular site at two weeks. Sirolimus was extracted from various segments of the juxta-anastomotic tissues and the drug concentrations were determined using HPLC MS/MS. Tissue sirolimus concentrations at one and two weeks were highest near the venous anastomosis, which were approximately 100- to 500-fold greater than the concentrations necessary to inhibit vascular smooth muscle cell proliferation in vitro. Drug concentrations remained above the inhibitory concentrations for at least six weeks post-operatively. Thus, serial injections of sustained-delivery polymer gel loaded with sirolimus can provide high localized concentrations at target vascular tissues and thus may be useful for the prevention and treatment of vascular proliferative disorders such as hemodialysis graft stenosis. In addition, MRI is useful for the monitoring of the location of the drug depot.

Lesion complexity determines arterial drug distribution after local drug delivery

Though stents are deployed in diseased arteries drug distribution has only been quantified in intact, non-diseased vessels. We correlated steady-state arterial drug distribution with tissue ultrastructure and composition in abdominal aortae from atherosclerotic human autopsy specimens and rabbits with lesions induced by dietary manipulation and controlled injury. Paclitaxel, everolimus, and sirolimus depositions in the human aortae were maximal in the media and scaled inversely with lipid content. Net tissue paclitaxel and everolimus levels were indistinguishable in mildly injured rabbit arteries independent of diet. Yet, serial sectioning of cryopreserved arterial segments demonstrated a differential transmural deposition pattern that was amplified with disease and correlated with the expression of their intracellular targets, tubulin and FKBP-12. Tubulin distribution and paclitaxel binding increased with vascular injury and macrophage infiltration, and were reduced with lipid content. Sirolimus analogs and their specific binding target FKBP-12 were less sensitive to alterations of diet in mildly injured arteries, presumably reflecting a faster transient response of FKBP-12 to injury. The data demonstrate that disease-induced changes in the distribution of drug-binding proteins and interstitial lipid alter the distribution of these drugs, forcing one to consider how disease might affect the evaluation and efficacy of the local release of these and like compounds.

Serial intravascular ultrasound analysis of peri-stent remodeling and proximal and distal edge effects after sirolimus-eluting or paclitaxel-eluting stent implantation in patients with diabetes mellitus

Patients with diabetes have an increased risk of in-stent restenosis after coronary stent implantation. Serial intravascular ultrasound was used to study chronic arterial responses and edge effects after implantation of Cypher (Cordis, Johnson & Johnson, Miami Lakes, Florida) or Taxus (Boston Scientific, Maple Grove, Minnesota) stents in diabetic patients. Seventy-four diabetic patients were randomly assigned to Cypher or Taxus stent implantation. Intravascular ultrasound of 5-mm long segments immediately proximal and distal to the stent was performed after the procedure and at the 8-month follow-up. The increase in peri-stent external elastic membrane (EEM) volume was more pronounced in the Taxus group (292.4 +/- 132.6 to 309.5 +/- 146.8 mm(3)) than in the Cypher group (274.4 +/- 137.2 to 275.4 +/- 140.1 mm(3); p = 0.005). Peri-stent plaque volume increased in the Taxus group (152.5 +/- 73.7 to 166.1 +/- 85.1 mm(3)), but was unchanged in the Cypher group (153.5 +/- 75.5 to 151.5 +/- 75.8 mm(3); p = 0.002). In proximal and distal reference segments, mean lumen area decreased within the entire 5-mm edge segment (proximal and distal) because of plaque progression (distal, 5.5 +/- 3.6 to 5.8 +/- 3.7 mm(2); p = 0.097; proximal, 8.1 +/- 2.7 to 8.7 +/- 2.9 mm(2); p = 0.006) without remodeling (change in EEM) in the Taxus group. Conversely, there were no significant changes in reference-segment EEM or plaque areas in the Cypher group. In conclusion, in diabetic patients, Taxus stent implantation was associated with increased (1) peri-stent EEM volume and peri-stent plaque, and (2) stent edge plaque progression accompanied by lumen reduction without remodeling. These findings were not seen in Cypher stents.

Late stent malapposition risk is higher after drug-eluting stent compared with bare-metal stent implantation and associates with late stent thrombosis

AIMS

Late stent malapposition (LSM) may be acquired (LASM) or persistent. LSM may play a role in patients who develop late stent thrombosis (ST). Our objective was to compare the risk of LASM in bare metal stents (BMS) with drug-eluting stents (DES) and to investigate the possible association of both acquired and persistent LSM with (very) late ST.

METHODS AND RESULTS

We searched PubMed and relevant sources from January 2002 to December 2007. Inclusion criteria were: (a) intra-vascular ultrasonography (IVUS) at both post-stent implantation and follow-up; (b) 6-9-month-follow-up IVUS; (c) implantation of either BMS or the following DES: sirolimus, paclitaxel, everolimus, or zotarolimus; and (d) follow-up for LSM. Of 33 articles retrieved for detailed evaluation, 17 met the inclusion criteria. The risk of LASM in patients with DES was four times higher compared with BMS (OR = 4.36, CI 95% 1.74-10.94) in randomized clinical trials. The risk of (very) late ST in patients with LSM (five studies) was higher compared with those without LSM (OR = 6.51, CI 95% 1.34-34.91).

CONCLUSION

In our meta-analysis, the risk of LASM is strongly increased after DES implantation compared with BMS. Furthermore, LSM seems to be associated with late and very late ST.

Drug-eluting stents for the treatment of ostial coronary lesions: comparison of sirolimus-eluting stent with paclitaxel-eluting stent

BACKGROUND

Treatment of ostial coronary lesions represents a challenge for interventional cardiologists. The efficacy of drug-eluting stents (DES) has been demonstrated as improving the outcomes of patients in a few studies. It is not known, however, which DES, sirolimus-eluting stent (SES) versus paclitaxel-eluting stent (PES), is superior for the treatment of ostial lesions.

METHODS

In this retrospective study, 95 consecutive patients with de-novo ostial lesions underwent coronary SES (n=47, lesions=48) or PES implantation (n=45, lesions=47), and quantitative coronary analysis was performed at the time of stent implantation and subsequently at 8 months post stenting. Ostial lesion was defined as > or =50% diameter stenosis rising within 3 mm of either left anterior descending coronary artery or left circumflex artery or right coronary artery measured by quantitative coronary analysis. Major adverse cardiac events including death, thrombosis, nonfatal myocardial infarction, and target lesion revascularization were compared between the two groups.

RESULTS

Baseline clinical and angiographic characteristics were well balanced between the two groups. At 8 months clinical and angiographic follow-up, overall major adverse cardiac events and target lesion revascularization rates were similar in both groups (6.4 vs. 11.2%, P=0.184; 4.3 vs. 8.9%, P=0.170, respectively). The in-stent and in-segment restenosis were, however, significantly higher in PES group compared with SES group (15.5 vs. 0%, P=0.001; 22.2 vs. 4.3%, P=0.003). Similarly, the late loss in both in-stent and in-segment was significantly higher in the PES group than in SES group (0.65+ or -0.67 vs. 0.16+ or -0.18 mm; 0.68+ or -0.65 vs. 0.15+ or -0.12 mm; P<0.001, respectively).

CONCLUSION

In this small sample-size, nonrandomized, and nonprospective study, the data indicated that implantation of DES appears safe and effective for the treatment of patients with de-novo ostial coronary lesions, but SES implantation showed more favorable results in respect of restenosis compared with PES implantation.

Comparison of changes in early inflammatory markers between sirolimus- and paclitaxel-eluting stent implantation

BACKGROUND

Systemic inflammation after coronary intervention identifies patients at increased risk of subsequent cardiac events. Cardiac events, especially in-stent restenosis, are less frequent after use of sirolimus-eluting stent (SES) compared with paclitaxel-eluting stent (PES). However, the underlying mechanism for this disparity is not well investigated. We hypothesize that an attenuated inflammatory response after SES implantation may be a contributor.

PURPOSE

In the present study, we sought to determine the early inflammatory response after SES implantation in patients with single-vessel disease compared with PES implantation, and evaluate the relationship between inflammatory response and late clinical outcomes in a randomized design.

METHODS

Thirty-two patients with stable angina were randomly enrolled into the two groups, SES or PSE group (n = 16 respectively). Peripheral blood samples were taken before PCI, 24 and 72 h after stenting. The plasma concentrations of C-reactive protein (CRP) and interleukin-6 (IL-6) were determined by enzyme-linked immunosorbent assay (ELISA). The clinical and angiographic follow-up was performed at 8 months after stenting.

RESULTS

The data showed that there was no significant difference in clinical and angiographic baseline characteristics between the two groups. The plasma CRP and IL-6 levels at 24 h after stenting were significant higher in both groups compared with baseline (p < 0.01 respectively). Likewise, the CRP levels at 72 h after stenting were also significant higher compared with baseline in both groups (p < 0.01 respectively). However, the plasma levels of IL-6 at 24 h and CRP at 72 h after stenting were higher in PES group compared with SES group (p < 0.05). At 8 months follow-up, the rates of major adverse cardiac events, target lesion revascularization, in-stent and in-segment restenosis were similar in both groups. However, the late loss in both in-stent and in-segment was significantly higher in the PES group than in SES group (p < 0.001 respectively).

CONCLUSIONS

Our findings suggest that a drug-eluting stent implantation could trigger a systemic inflammatory response as previously demonstrated. However, SES implantation results in a lower inflammatory response compared with PES implantation, which seems to be associated with greater late of in-stent and in-segment loss at 8-month follow-up with PES.