Paclitaxel and sirolimus differentially affect growth and motility of endothelial progenitor cells and coronary artery smooth muscle cells

Treatment of coronary lesions with a novel crystalline sirolimus-coated balloon

Background

There is mounting data supporting the use of drug-coated balloons (DCB) not only for treatment of in-stent restenosis (ISR), but also in native coronary artery disease. So far, paclitaxel-coated balloons represented the mainstay DCBs. The SeQuent® crystalline sirolimus-coated balloon (SCB) (B.Braun Medical Inc, Germany) represents a novel DCB, which allows a sustained release of the limus-drug. We evaluated its performance in an all-comer cohort, including complex coronary lesions.

Methods

Consecutive patients treated with the SeQuent® SCB were analyzed from the prospective SIROOP registry (NCT04988685). We assessed clinical outcomes, including major adverse cardiovascular events (MACE), target lesion revascularization (TLR), target vessel myocardial infarction (TV-MI) and cardiovascular death. Angiograms and outcomes were independently adjudicated.

Results

From March 2021 to March 2023, we enrolled 126 patients and lesions, of which 100 (79%) treated using a "DCB-only" strategy and 26 (21%) with a hybrid approach (DES + DCB). The mean age was 68 ± 10 years, 48 (38%) patients had an acute coronary syndrome. Regarding lesion characteristics, ISR was treated in 27 (21%), 11 (9%) underwent CTO-PCI and 59 (47%) of the vessels were moderate to severe calcified. Procedural success rate was 100%. At a median follow-up time of 12.7 (IQR 12; 14.2) months, MACE occurred in 5 patients (4.3%). No acute vessel closure was observed.

Conclusions

Our data indicates promising outcomes following treatment with this novel crystalline SCB in an all-comer cohort with complex coronary lesions. These results require further investigation with randomized trials.

Paclitexel versus sirolimus-coated balloon in the treatment of coronary instent restenosis

BACKGROUND

Few studies compared paclitaxel-coated balloon (PCB) versus sirolimus-coated balloon (SCB) in the treatment of drug-eluting stent (DES) instent restenosis (ISR).

METHODS

Between November 5, 2009, and October 14, 2020, in our center 212 patients with first DES-ISR were treated with PCB (Restore®; Cardionovum GmbH, Bonn, Germany), whereas 230 patients were treated with SCB (Devoir®; MINVASYS SAS, Gennevilliers, France). Following a propensity matching, 186 patients were included into PCB group (PCB group), and in the SCB group (SCB group). The primary purpose of the study was the 1-year target lesion failure (TLF) rate, including cardiac death, target vessel-related myocardial infarction, and repeated target lesion or target vessel revascularization.

RESULTS

Procedural success occurred in all cases. Fully optimal predilation (that is, balloon-to-stent ratio >0.91, time of DCB inflation >60 sec, and residual percent diameter stenosis after lesion preparation <20%) was observed more often in the SCB group (126 [68%] patients versus 106 [57%] patients; P=0.042). One-year TLF occurred in 29 (15.5%) patients in the SCB group and in 32 (17%) patients in the PCB group (OR=1.12 [0.65-1.95]; P=0.78). By logistic Cox regression analysis fully optimal predilation (OR=0.06; 95% CI: 0.01-0.21; P<0.001) but not DCB type (OR=0.74; 95% CI: 0.41-1.31; P=0.29) was independent predictor of 1-year TLF.

CONCLUSIONS

The current study suggests that 1-year TLF is not statistically and clinically different in patients with DES ISR treated with a PCB and a SCB.

Clinical expert consensus document on drug-coated balloon for coronary artery disease from the Japanese Association of Cardiovascular Intervention and Therapeutics

Drug-coated balloon (DCB) technology was developed to deliver the antiproliferative drugs to the vessel wall without leaving any permanent prosthesis or durable polymers. The absence of foreign material can reduce the risk of very late stent failure, improve the ability to perform bypass-graft surgery, and reduce the need for long-term dual antiplatelet therapy, potentially reducing associated bleeding complications. The DCB technology, like the bioresorbable scaffolds, is expected to be a therapeutic approach that facilitates the "leave nothing behind" strategy. Although newer generation drug-eluting stents are the most common therapeutic strategy in modern percutaneous coronary interventions, the use of DCB is steadily increasing in Japan. Currently, the DCB is only indicated for treatment of in-stent restenosis or small vessel lesions (< 3.0 mm), but potential expansion for larger vessels (≥ 3.0 mm) may hasten its use in a wider range of lesions or patients with obstructive coronary artery disease. The task force of the Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT) was convened to describe the expert consensus on DCBs. This document aims to summarize its concept, current clinical evidence, possible indications, technical considerations, and future perspectives.

Treatment of Coronary De Novo Lesions by a Sirolimus- or Paclitaxel-Coated Balloon

OBJECTIVES

The aim of this randomized controlled trial was to investigate a novel sirolimus-coated balloon (SCB) compared with the best investigated paclitaxel-coated balloon (PCB).

BACKGROUND

There is increasing clinical evidence for the treatment of coronary de novo disease using drug-coated balloons. However, it is unclear whether paclitaxel remains the drug of choice or if sirolimus is an alternative, in analogy to drug-eluting stents.

METHODS

Seventy patients with coronary de novo lesions were enrolled in a randomized, multicenter trial to compare a novel SCB (SeQuent SCB, B. Braun Melsungen; 4 μg/mm²) with a PCB (SeQuent Please, B. Braun Melsungen; 3 μg/mm²). The primary endpoint was angiographic late lumen loss (LLL) at 6 months. Secondary endpoints included major adverse cardiovascular events and individual clinical endpoints such as cardiac death, target lesion myocardial infarction, clinically driven target lesion revascularization, and binary restenosis.

RESULTS

Quantitative coronary angiography revealed no differences in baseline parameters. After 6 months, in-segment LLL was 0.01 ± 0.33 mm in the PCB group versus 0.10 ± 0.32 mm in the SCB group. The mean difference between SCB and PCB was 0.08 (95% CI: -0.07 to 0.24). Noninferiority at a predefined margin of 0.35 was shown. However, negative LLL was more frequent in the PCB group (60% of lesions vs 32% in the SCB group; P = 0.019). Major adverse cardiovascular events up to 12 months also did not differ between the groups.

CONCLUSIONS

This first-in-human comparison of a novel SCB with a crystalline coating showed similar angiographic outcomes in the treatment of coronary de novo disease compared with a clinically proven PCB. However, late luminal enlargement was more frequently observed after PCB treatment. (Treatment of Coronary De-Novo Stenosis by a Sirolimus Coated Balloon or a Paclitaxel Coated Balloon Catheter Malaysia [SCBDNMAL]; NCT04017364).

Comparison of 2 Different Paclitaxel-Coated Balloons in Coronary In-Stent Restenosis: A Randomized Controlled Trial

BACKGROUND

Drug-coated balloons (DCBs) offer an effective treatment for in-stent restenosis (ISR). The Genoss DCB is a novel paclitaxel-coated balloon with a shellac plus vitamin E excipient that enhances drug delivery to the target lesion, minimizing restenosis.

OBJECTIVES

This study aimed to investigate the angiographic efficacy, clinical safety, and effectiveness of the novel shellac plus vitamin E-based DCB in a randomized controlled trial designed to enable regulatory approval of this new device in South Korea.

METHODS

This noninferiority trial randomized patients experiencing their first ISR to the novel shellac plus vitamin E-based DCB or the reference SeQuent Please iopromide-based DCB in a 1:1 ratio. All patients underwent planned angiographic and clinical follow-up at 6 months. The study was powered for the primary endpoint of 6 months in-segment late lumen loss (LLL).

RESULTS

A total of 82 patients from 7 centers were randomized to either the novel shellac plus vitamin E-based DCB group (n = 41) or the reference iopromide-based DCB group (n = 41). The 6-month in-segment LLL was 0.15 ± 0.43 mm with the novel DCB compared with 0.24 ± 0.39 mm with the reference device. The 1-sided 97.5% upper confidence limit of the difference was 0.13 mm, lower than the noninferiority limit of 0.29 mm, achieving noninferiority (P for noninferiority = 0.001). Major cardiovascular events were comparable between 2 groups at 6 months (7.7% for the novel DCB vs 10.3% for the reference DCB; P = 0.692).

CONCLUSIONS

In this multicenter, head-to-head comparison randomized trial, the novel shellac plus vitamin E-based DCB showed a comparable result to the reference iopromide-based device for the primary endpoint of 6-month in-segment LLL for the treatment of coronary ISR. (Compare the Safety and Efficacy of Genoss® DCB and SeQuent® Please in Korean Patient With Coronary In-stent Restenosis; NCT04405063).

Bare Metal Stents on Resveratrol-Coated Balloons in Porcine Coronary and Peripheral Arteries

Balloon angioplasty and stent implantation are standard techniques to reopen stenotic vessels. Often, balloons or stents coated with cytostatic drugs are used to prevent re-occlusion of the arteries. Resveratrol, which is known for its numerous beneficial effects on cardiovascular health, is used as an antioxidant additive on paclitaxel-coated balloon catheters. What is still unclear is whether resveratrol-only balloon coating in combination with a bare metal stent (BMS) also has positive effects on vascular healing. Here, we analyzed neointimal thickening, fibrin deposition, inflammation, vasa vasorum density, and reendothelialization after implantation of BMS via a resveratrol coated balloon approach in a porcine model. In general, resveratrol treatment did not result in significantly altered responses compared to the control group in peripheral arteries. In coronary arteries, an increase in vasa vasorum density became evident three days after resveratrol treatment compared to the control group and abolished up to day 7. Significant effects of the resveratrol treatment on the fibrin score or intima-media area were transient and restricted to either peripheral or coronary arteries. In conclusion, local single-dose resveratrol treatment via a resveratrol-only coated balloon and BMS approach did not lead to adverse systemic or local effects, but also no significant beneficial effects on vascular healing were detected in the current study.

Drug-coated Balloons for Small Coronary Disease-A Literature Review

PURPOSE OF REVIEW

In the interventional treatment of coronary artery disease, new-generation drug-eluting stents (DES) currently are the standard treatment. In addition, drug-coated balloons (DCB) are a well-established option for the treatment of in-stent restenosis in both bare-metal stents (BMS) and DES, where DCBs deliver an antiproliferative drug without the necessity of re-implanting a stent. Since the field of use for DCB has increasingly been extended to other indications such as de novo lesions in small vessel disease (SVD), a review of literature may be useful.

RECENT FINDINGS

Recent randomized trial data show good efficacy and safety for DCB in de novo lesions, especially in small coronary arteries, and confirm long-term clinical efficacy and safety up to three years. DCB are an attractive and safe option in the treatment of de novo lesions in SVD.

Citric acid functionalized nitinol stent surface promotes endothelial cell healing

While drug-eluting stents containing anti-proliferative agents inhibit proliferation of smooth muscle cells (SMCs), they also delay the regrowth of the endothelial cells which can result in subsequent development of restenosis. Acidic extracellular environments promote cell anchorage and migration by inducing conformational change in integrins, the main cell adhesion proteins. This study addresses the feasibility of a citric acid (CA) functionalized nitinol stent for improving vascular biocompatibility, specifically enhancing endothelialization. CA functionalized nitinol vascular stents are compared to commercial bare metal (Zilver Flex) and paclitaxel eluting stents (Zilver PTX) in terms of re-endothelialization. To study the effect of stent coatings, a stent conditioned media methodology was developed in an attempt to represent in vivo conditions. Overall, distinct advantages of the CA functionalized nitinol stent over commercial Zilver PTX DES and Zilver Flex BMS stents in terms of endothelial cell adhesion, migration, and proliferation are reported. These novel findings indicate the potential of a CA functionalized stent to serve as a bioactive and therapeutic surface for re-endothelialization, perhaps in combination with a SMC proliferation inhibitor coating, to prevent restenosis.

Serial assessment of de novo coronary lesions after drug-coated balloon treatment analyzed by intravascular ultrasound: A comparison between acute coronary syndrome and stable angina pectoris

BACKGROUND

This study aimed to assess the serial changes in de novo coronary lesions, including acute coronary syndrome (ACS), treated with a drug-coated balloon (DCB).

METHODS

In this retrospective single-center study, the intravascular changes in patients with de novo lesions treated with DCB were evaluated with serial intravascular ultrasound (IVUS) pre-procedure, post-procedure, and at follow-up. A two-dimensional IVUS measurement was performed with slices at 1 mm intervals in the treated lesion.

RESULTS

This study comprised 40 lesions, including 27 lesions with stable angina pectoris (SAP) and 13 ACS. IVUS showed that the median vessel and lumen area increased significantly from pre-procedure to post-procedure and from post-procedure to follow-up. The median plaque area decreased significantly from pre-procedure to post-procedure and follow-up. The IVUS between ACS and SAP demonstrated that the total vessel volume and the total lumen volume increased, and the total atheroma volume decreased significantly from pre- to follow-up in both groups. The percent change in the lumen area increased, and the plaque area decreased significantly in ACS compared to SAP from pre- to post-procedure and follow-up.

CONCLUSION

The findings of this study suggest that DCB treatment for de novo coronary lesions in patients with ACS and SAP may maintain anatomical patency and increase lumen with positive vessel remodeling and regression of plaque.

Drug-Coated Balloon Angioplasty for Carotid Artery Occlusion Caused by Takayasu Arteritis

A 27-year-old male patient suffering from dizziness and right amaurosis was diagnosed with Takayasu arteritis (TA). Computed tomography angiography showed that all the supra-aortic arteries were occluded except an aberrant right subclavian artery. The patient underwent drug-coated balloon dilatation at the lesion of the right common carotid artery and performed well after the procedure. Six months later, the patient's symptoms have not recurred and computed tomography angiography showed the right carotid artery remains patency. The supra-aortic artery lesions in TA may be a potential novel indication for a drug-coated balloon.

Treatment of Coronary Drug-Eluting Stent Restenosis by a Sirolimus- or Paclitaxel-Coated Balloon

OBJECTIVES

The aim of this randomized controlled trial was to investigate a novel sirolimus-coated balloon (SCB) compared with the best investigated paclitaxel-coated balloon (PCB).

BACKGROUND

Treatment of coronary in-stent restenosis (ISR) remains challenging. PCBs are an established treatment option outside the United States with a Class I, Level of Evidence: A recommendation in the European guidelines. However, their efficacy is better in bare-metal stent (BMS) ISR compared with drug-eluting stent (DES) ISR.

METHODS

Fifty patients with DES ISR were enrolled in a randomized, multicenter trial to compare a novel SCB (SeQuent SCB, 4 μg/mm²) with a clinically proven PCB (SeQuent Please Neo, 3 μg/mm²) in coronary DES ISR. The primary endpoint was angiographic late lumen loss at 6 months. Secondary endpoints included procedural success, major adverse cardiovascular events, and individual clinical endpoints such as stent thrombosis, cardiac death, target lesion myocardial infarction, clinically driven target lesion revascularization, and binary restenosis.

RESULTS

Quantitative coronary angiography revealed no differences in baseline parameters. After 6 months, in-segment late lumen loss was 0.21 ± 0.54 mm in the PCB group versus 0.17 ± 0.55 mm in the SCB group (p = NS; per-protocol analysis). Clinical events up to 12 months also did not differ between the groups.

CONCLUSIONS

This first-in-man comparison of a novel SCB with a crystalline coating shows similar angiographic outcomes in the treatment of coronary DES ISR compared with a clinically proven PCB. (Treatment of Coronary In-Stent Restenosis by a Sirolimus [Rapamycin] Coated Balloon or a Paclitaxel Coated Balloon [FIM LIMUS DCB]; NCT02996318).

One-year results of drug-coated balloons for long and occlusive Femoropopliteal artery disease: a single-arm trial

Background

The performance of drug-coated balloons (DCBs) in femoropopliteal interventions has been proven through randomized trials in short lesions and lesions with relatively low proportion of occlusions. There is limited evidence of DCBs in long or occlusive lesions. This study is to investigate the efficacy of the paclitaxel-coated balloon for treatment of long and occlusive femoropopliteal arterial lesions.

Methods

A single-arm trial including 44 femoropopliteal lesions (chronic total occlusion (CTO) plus > 10 cm) treated with DCBs was performed to collect data of average 1-year follow-up. Endpoints contain primary patency, target lesion revascularization (TLR), amelioration of the Rutherford classification, change of ankle brachial index (ABI) and major adverse events.

Results

Technical success is 97.7% while device success is 100%. Mean lesion length was 186 ± 86.3 cm. Stent implantation was performed in 13.6%. Cumulative probability of primary patency was 78.8% ± 6.8% at 1 year while that of freedom from TLR was 91.4% ± 4.9%. Rutherford classification improved from average 3.3 ± 1.0 to 2.1 ± 1.4 (p < 0.001) at follow-up with a 72.7% amelioration rate. Ankle-branchial index changed from 0.33 ± 0.40 to 0.67 ± 0.37 (p = 0.002). No major adverse event was observed.

Conclusion

These results suggest that it is safe and effective to treat long and totally occlusive femoropopliteal artery disease with DCBs. Further studies are demanded to confirm these results.

Resveratrol-Coated Balloon Catheters in Porcine Coronary and Peripheral Arteries

Angioplasty aiming at vascular dilatation causes endothelial denudation and induces complex inflammatory responses that affect vascular healing, including delayed reendothelialization and excessive neointima proliferation. Resveratrol is known for multiple beneficial effects on the vessel wall after systemic treatment or sustained release from a stent. It is also used as an additive on drug-coated balloon catheters (DCB). In this study, the effect of a single dose of resveratrol, three days to four weeks after administration as a balloon coating during angioplasty, was investigated. Sixteen pigs underwent angioplasty with resveratrol-coated or uncoated balloon catheters in coronary and peripheral arteries. Vessels were overstretched by approximately 20% to enhance vessel wall injury and to produce persistent vessel wall irritation. A significantly reduced number of micro vessels and macrophages in the adventitia, as well as an improved reendothelialization of the vessel lumen, were observed in resveratrol-treated peripheral arteries. The coronaries had a much higher injury score compared to peripheral vessels. Resveratrol-dependent reduction of macrophages, micro vessels or acceleration of reendothelialization was not evident in the coronary vessels. Additionally, no significant effect on neointima proliferation and inflammation score in either vessel territory was observed as a result of resveratrol treatment. In conclusion, the results suggest that resveratrol diminishes the inflammatory response and promotes vascular healing in peripheral arteries. These same effects are absent in more severely injured coronary arteries.

Relationship Between Postoperative Neutrophil-Lymphocyte Ratio and 6-Month Primary Patency of Percutaneous Transluminal Angioplasty in Femoropopliteal disease With Drug-Coated and Uncoated Balloons

We investigated the relationship of postoperative neutrophil-lymphocyte ratio (NLR) with 6-month primary patency of percutaneous transluminal angioplasty (PTA) in femoropopliteal disease using drug-coated balloon (DCB) or uncoated balloon (UCB). This retrospective study included 106 patients who received DCB (n = 44) or UCB (n = 62). The postoperative NLR was lower in the DCB group than that in the UCB group (2.60 vs 3.23; P = .004), and 6-month primary patency rate was significantly higher in DCB group than that in the UCB group (77.3% vs 53.2%; P = .011). Multivariate logistic analysis showed that the postoperative NLR was an independent predictor of 6-month primary patency after PTA in patients with femoropopliteal disease (odds ratio: 1.589, 95% confidence interval: 1.078-2.343; P = .019). The cutoff value of postoperative NLR was 3.05 for prediction of 6-month primary patency, with a sensitivity of 64.1% and specificity of 65.7%. The 6-month primary patency rate in the NLR ≤3.05 group was higher than that in the NLR >3.05 group (75.9% vs 47.9%; P = .003). In conclusion, DCB may improve early primary patency by inhibiting inflammation. A higher postoperative NLR was associated with early restenosis.

Hypercholesterolemia after conversion to sirolimus as primary immunosuppression and cardiac allograft vasculopathy in heart transplant recipients

BACKGROUND

Sirolimus (SRL) attenuates cardiac allograft vasculopathy (CAV) progression after heart transplantation (HT) but often results in hyperlipidemia. In this study we investigated the differential effects of SRL-based and calcineurin inhibitor (CNI)-based immunosuppression on CAV progression and clinical outcomes in HT recipients.

METHODS

CAV progression was assessed by coronary intravascular ultrasound (IVUS) as changes in volumetric measurements after correction to time between the first and last follow-up IVUS exams. CAV progression rate and CAV-associated events were compared between patients with mean follow-up low-density lipoprotein (LDL) <100 mg/dl (lower level or LL) and ≥100 mg/dl (higher level or HL) in the SRL and CNI groups.

RESULTS

We identified 227 patients on SRL (LL: 118; HL: 109) and 96 on CNI (LL: 56; HL: 40), with a median follow-up of 6.7 years. Clinical characteristics did not differ between the LL and HL groups and all patients were on statins. In the SRL arm, there were no significant differences in CAV progression rate and there were no differences in all-cause mortality and CAV-associated events between the LL and HL groups. In the CNI arm, the Δ change in plaque volume normalized to segment length and time of follow-up (PV/SL/year) (0.55 ± 0.53 vs 1.53 ± 2.32, p = 0.003) and Δ change in plaque index per year (defined as PV/vessel volume ratio) (3.1 ± 3.7% vs 6.3 ± 10.4%; p = 0.034) were significantly lower in the LL than the HL group. After adjusting for patient characteristics, HL was associated with higher rates of advanced CAV requiring coronary angioplasty (hazard ratio [HR] 3.0, 95% confidence interval [CI] 1.05 to 9.40, p = 0.040) and higher rates of all CAV-associated events (HR 2.2, 95% CI 1.10 to 4.54, p = 0.026) in these CNI-treated subjects.

CONCLUSION

Unlike CNI-based immunosuppression, the effects of SRL on attenuating CAV progression are independent of LDL cholesterol levels post-HT.

Zedoary Guaiane-Type Sesquiterpenes-Eluting Stents Accelerate Endothelial Healing Without Neointimal Hyperplasia in a Porcine Coronary Artery Model

Objective:

The effects of zedoary guaiane-type sesquiterpenes (ZGS)-based eluting stent (ZES) in accelerating reendothelialization and inhibiting neointimal hyperplasia were examined in a porcine coronary artery model.

Methods:

The ZES was prepared by polymer-free 316L stainless metal stents. Sirolimus-eluting stents (SES) and bare metal stents (BMS) with identical platforms were used as controls. Stents with 15 mm in length and 2.0 to 3.5 mm in diameter were implanted in porcine coronary arteries. Scanning electron microscopy (SEM) and histopathology were performed to assess the reendothelialization and neointimal hyperplasia. The 3-(4, 5-dimethylthiazol-2yl)-2, 5-diphenyl-2H-tetrazoliumbromide assay and flow cytometry were used to assess the influence of ZGS on human umbilical vascular endothelial cells (HUVECs).

Results:

At 7 days, SEM showed that percentage of endothelial coverage area was 94.04% ± 5.01% for ZES, 47.59% ± 19.91% for SES ( P < .01 for ZES vs SES), and 59.58% ± 19.61% for BMS ( P < .05 for ZES vs BMS). At 28 days, the percentage of coverage area was 98.51% ± 1.86% for ZES, 86.18% ± 8.16% for SES ( P < .05 for ZES vs SES), and 94.26% ± 5.58% for BMS. Neointimal area and stenosis were significantly lower in ZES (1.07 ± 0.48 mm2, 27.66% ± 12.20%) compared to BMS (1.73 ± 0.69 mm2, 44.08% ± 15.03%, both P < .01, respectively), with no difference in SES (0.94 ± 0.12 mm2, 28.87% ± 6.00%, both P > .05, respectively). The ZGS also promoted HUVECs viability and improved HUVECs proliferation compared to sirolimus.

Conclusion:

The ZES accelerated reendothelialization and suppressed neointimal hyperplasia in a porcine coronary artery model, with beneficial effects on HUVECs.

Novel Sirolimus–Coated Balloon Catheter

Background—

Limus-eluting stents are dominating coronary interventions, although paclitaxel is the only drug on balloon catheters with proven inhibition of restenosis. Neointimal inhibition by limus-coated balloons has been shown in few animal studies, but data from randomized clinical trials are not available. The aim of the present preclinical studies was to achieve high and persistent sirolimus levels in the vessel wall after administration by a coated balloon.

Methods and Results—

Different coating formulations and doses were studied in the porcine coronary model to investigate sirolimus tissue levels at different time points as well as efficacy at 1 month using quantitative coronary angiography and histomorphometry. Loss of the selected coating in the valve, guiding catheter, and blood was low (2±14% of dose). Acute drug transfer to the vessel wall was 14.4±4.6% with the crystalline coating, whereas the amorphous coatings were less effective in this respect. Persistence of sirolimus in the vessel wall until 1 month was 40% to 50% of the transferred drug. At 1-month follow-up, a modest but significant reduction of neointimal growth was demonstrated in a dose range from 4 μg/mm 2 to 2×7 μg/mm 2 , for example, maximum neointimal thickness of 0.38±0.13 versus 0.65±0.21 mm in the uncoated control group.

Conclusions—

Various sirolimus-coated balloons effectively reduce neointimal proliferation in the porcine coronary model but differ considerably in retention time in the vessel wall. It has to be determined if such a formulation with persistent high vessel concentration will result in a relevant clinical effect.

G-CSF Predicts Cardiovascular Events in Patients with Stable Coronary Artery Disease

Granulocyte-colony-stimulating-factor (G-CSF) induces mobilization of progenitor cells but may also exert pro-inflammatory and pro-thrombotic effects. Treatment with recombinant G-CSF after acute myocardial infarction is currently under examination and has been associated with in-stent restenosis. However, it is not known whether plasma levels of endogenous G-CSF are also associated with an increased cardiovascular risk. Therefore we included 280 patients with angiographically proven stable coronary artery disease. G-CSF was measured by specific ELISA and patients were followed for a median of 30 months for the occurrence of major adverse cardiovascular events (MACE: death, myocardial infarction, re-hospitalization). Those with cardiac events during follow-up showed significant higher G-CSF levels (32.3 pg/mL IQR 21.4-40.5 pg/mL vs. 24.6 pg/mL IQR 16.4-34.9 pg/mL; p<0.05) at baseline. Patients with G-CSF plasma levels above the median had a 2-fold increased risk for MACE (p<0.05). This was independent from established cardiovascular risk factors. In addition, G-CSF above the median was a predictor of clinical in-stent restenosis after implantation of bare-metal stents (6.6% vs. 19.4%; p<0.05) but not of drug-eluting stents (7.7% vs. 7.6%; p = 0.98). This data suggests that endogenous plasma levels of G-CSF predict cardiovascular events independently from established cardiac risk factors and are associated with increased in-stent restenosis rates after implantation of bare metal stents.

Local delivery of paclitaxel in the treatment of peripheral arterial disease

BACKGROUND

Despite advancements from balloon angioplasty to drug-eluting stents, primary patency rates after endovascular revascularization of peripheral artery disease have remained inferior compared to surgery. Endovascular revascularization has been limited by restenosis and mechanical stent failure. Thus, there is increased research into other nonstent-based local drug delivery modalities, which can provide an active drug to inhibit restenosis focally and avoid the risk of systemic adverse effects.

METHODS

This review will summarize the unique properties of paclitaxel and studies on paclitaxel local delivery for the treatment of peripheral artery disease. A MEDLINE search for relevant peer-reviewed scientific literature published in English was conducted. Search terms included but were not limited to paclitaxel pharmacodynamics, paclitaxel local drug delivery, and drug eluting balloons, with a focus on the use of paclitaxel in the context of coronary and peripheral vascular disease.

RESULTS

The primary search produced 182 results of which 51 papers were relevant. Of the 51 relevant papers, 27 were original research papers and 24 were either review papers, commentary or opinion papers.

CONCLUSIONS

Paclitaxel has several chemical properties, which make it ideal for local drug delivery including its hydrophobicity, ability to concentrate into the arterial intima layer and prolonged effect on cells even after brief exposure periods. Local delivery of paclitaxel via injection catheters, balloon catheters and coated balloons has shown encouraging results in terms of efficacy and safety in small-scale animal and clinical studies. Additional preclinical and clinical studies are needed to determine the long-term efficacy and safety of these treatments in humans.

The GroEL protein of Porphyromonas gingivalis accelerates tumor growth by enhancing endothelial progenitor cell function and neovascularization

Porphyromonas gingivalis is a bacterial species that causes destruction of periodontal tissues. Additionally, previous evidence indicates that GroEL from P. gingivalis may possess biological activities involved in systemic inflammation, especially inflammation involved in the progression of periodontal diseases. The literature has established a relationship between periodontal disease and cancer. However, it is unclear whether P. gingivalis GroEL enhances tumor growth. Here, we investigated the effects of P. gingivalis GroEL on neovasculogenesis in C26 carcinoma cell-carrying BALB/c mice and chick eggs in vivo as well as its effect on human endothelial progenitor cells (EPC) in vitro. We found that GroEL treatment accelerated tumor growth (tumor volume and weight) and increased the mortality rate in C26 cell-carrying BALB/c mice. GroEL promoted neovasculogenesis in chicken embryonic allantois and increased the circulating EPC level in BALB/c mice. Furthermore, GroEL effectively stimulated EPC migration and tube formation and increased E-selectin expression, which is mediated by eNOS production and p38 mitogen-activated protein kinase activation. Additionally, GroEL may enhance resistance against paclitaxel-induced cell cytotoxicity and senescence in EPC. In conclusion, P. gingivalis GroEL may act as a potent virulence factor, contributing to the neovasculogenesis of tumor cells and resulting in accelerated tumor growth.

The Eternal Tale of Dialysis Access Vessels and Restenosis: Are Drug-Eluting Balloons the Solution?

In dialysis access fistulas and grafts, percutaneous transluminal angioplasty (PTA) is frequently followed by restenosis development, which results in repeated periodical re-interventions. The technique of drug-eluting balloon (DEB) angioplasty has shown promising results in the treatment of femoropopliteal arteriosclerotic lesions. In contrast to arteriosclerotic arteries, dialysis access vessels host unfavorable hemodynamics due to the direct conduction of high-pressure fluid into a low-pressure system. Hence, the beneficial effect of DEB angioplasty may be limited in this system. However, a first prospective randomized trial on 40 patients with arteriovenous fistula or graft stenoses exhibited a significantly higher 6-month primary patency of the treated lesions after DEB angioplasty than after uncoated balloon angioplasty. Despite such a positive reference, general recommendations regarding the value of DEBs in dialysis access vessels cannot be considered as serious unless large randomized controlled trials have been performed.

Stem Cells on Biomaterials for Synthetic Grafts to Promote Vascular Healing

This review is divided into two interconnected parts, namely a biological and a chemical one. The focus of the first part is on the biological background for constructing tissue-engineered vascular grafts to promote vascular healing. Various cell types, such as embryonic, mesenchymal and induced pluripotent stem cells, progenitor cells and endothelial- and smooth muscle cells will be discussed with respect to their specific markers. The in vitro and in vivo models and their potential to treat vascular diseases are also introduced. The chemical part focuses on strategies using either artificial or natural polymers for scaffold fabrication, including decellularized cardiovascular tissue. An overview will be given on scaffold fabrication including conventional methods and nanotechnologies. Special attention is given to 3D network formation via different chemical and physical cross-linking methods. In particular, electron beam treatment is introduced as a method to combine 3D network formation and surface modification. The review includes recently published scientific data and patents which have been registered within the last decade.

Inhibition of Orai1-mediated Ca(2+) entry is a key mechanism of the antiproliferative action of sirolimus in human arterial smooth muscle

Sirolimus (rapamycin) is used in drug-eluting stent strategies and proved clearly superior in this application compared with other immunomodulators such as pimecrolimus. The molecular basis of this action of sirolimus in the vascular system is still incompletely understood. Measurements of cell proliferation in human coronary artery smooth muscle cells (hCASM) demonstrated a higher antiproliferative activity of sirolimus compared with pimecrolimus. Although sirolimus lacks inhibitory effects on calcineurin, nuclear factor of activated T-cell activation in hCASM was suppressed to a similar extent by both drugs at 10 μM. Sirolimus, but not pimecrolimus, inhibited agonist-induced and store-operated Ca(2+) entry as well as cAMP response element binding protein (CREB) phosphorylation in human arterial smooth muscle, suggesting the existence of an as-yet unrecognized inhibitory effect of sirolimus on Ca(2+) signaling and Ca(2+)-dependent gene transcription. Electrophysiological experiments revealed that only sirolimus but not pimecrolimus significantly blocked the classical stromal interaction molecule/Orai-mediated, store-operated Ca(2+) current reconstituted in human embryonic kidney cells (HEK293). A link between Orai function and proliferation was confirmed by dominant-negative knockout of Orai in hCASM. Analysis of the effects of sirolimus on cell proliferation and CREB activation in an in vitro model of arterial intervention using human aorta corroborated the ability of sirolimus to suppress stent implantation-induced CREB activation in human arteries. We suggest inhibition of store-operated Ca(2+) entry based on Orai channels and the resulting suppression of Ca(2+) transcription coupling as a key mechanism underlying the antiproliferative activity of sirolimus in human arteries. This mechanism of action is specific for sirolimus and not a general feature of drugs interacting with FK506-binding proteins.

An Egr-1-specific DNAzyme regulates Egr-1 and proliferating cell nuclear antigen expression in rat vascular smooth muscle cells

The aim of the present study was to transfect rat aortic smooth muscle cells with an early growth response factor-1 (Egr-1)-specific DNAzyme (ED5), to observe its effect on Egr-1 and proliferating cell nuclear antigen (PCNA) expression and to elucidate the mechanism of ED5-mediated inhibition of vascular smooth muscle cell (VSMC) proliferation. VSMCs in primary culture obtained by tissue block adhesion were identified by morphological observation and α smooth muscle actin (α-SM-actin) immunocytochemistry. The cells were then transfected with ED5 or scrambled ED5 (ED5SCR). The three groups of cells used in the present study were the control group, ED5 group and ED5SCR group. The expression levels of Egr-1 and PCNA protein were detected following transfection by analyzing and calculating the integral optical density value in each group. Primary culture of VSMCs and transfection of ED5 and ED5SCR were successfully accomplished. Following stimulation with 10% fetal calf serum, the Egr-1 protein was expressed most strongly at 1 h and demonstrated a declining trend over time; the expression of PCNA protein began at 4 h, peaked at 24 h and then demonstrated a slightly declining trend over time. Compared with the control group and the ED5SCR group, ED5 inhibited the expression of Egr-1 and PCNA (P<0.05). ED5 was able to inhibit the expression of Egr-1 and PCNA proteins in VSMCs to a certain extent and VSMC proliferation in vitro. DNAzyme gene therapy may be useful as a new method for treating vascular proliferative diseases, including atherosclerosis and restenosis.

Reliability of the McSweeney Acute and Prodromal Myocardial Infarction Symptom Survey among black and white women

BACKGROUND

Coronary heart disease (CHD) mortality rates are higher among women, particularly black, than men. Women's mortality rates may reflect difficulty in recognizing CHD prodromal symptoms (PS) but reliable screening instruments for women are scarce. The McSweeney Acute and Prodromal Myocardial Infarction Symptom Survey (MAPMISS) captures women's PS presentation, but has limited testing among black women.

AIM

To assess the test-retest reliability of the MAPMISS PS section for black and white women.

METHODS

The sample was recruited from women enrolled in a longitudinal study examining the predictive validity of the MAPMISS. The MAPMISS was re-administered to 42 women (22 white, 20 black) 3-5 days after baseline assessment.

RESULTS

Women endorsed an average of 7.5 PS (SD 4.8; range 0-20) initially and 7.6 (SD 4.7; range 0-20) at retest. Over half of the women (54.8%) of both races endorsed the same number of PS at test and retest; for 69%, the number endorsed at both testings differed by no more than one. Percentage agreement and kappa statistics on the number ofPS endorsed were excellent overall and by race. PS test and retest scores, reflecting PS intensity and frequency, were highly correlated overall (r = 0.92, p < 0.001) and separately for white (r = 0.93, p < 0.001) and black women (r = 0.91,p < 0.001). Racial differences were insignificant.

CONCLUSIONS

Findings indicate (i) the MAPMISS PS score has excellent test-retest reliability (r = 0.92) when administered to women without a history of CHD, and (ii) test-retest reliability is as strong for black (r = 0.91) as for white women (r = 0.93).