Drug-coated balloons in cardiovascular disease: benefits, challenges, and clinical applications

Exploring the Potential of MIM-Manufactured Porous NiTi as a Vascular Drug Delivery Material

Porous nickel-titanium (NiTi) manufactured using metal injection molding (MIM) has emerged as an innovative generation of drug-loaded stent materials. However, an increase in NiTi porosity may compromise its mechanical properties and cytocompatibility. This study aims to explore the potential of porous NiTi as a vascular drug delivery material and evaluate the impact of porosity on its drug loading and release, mechanical properties, and cytocompatibility. MIM, combined with the powder space-holder method, was used to fabricate porous NiTi alloys with three porosity levels. The mechanical properties of porous NiTi were assessed, as well as the surface cell growth capability. Furthermore, by loading rapamycin nanoparticles onto the surface and within the pores of porous NiTi, we evaluated the in vitro drug release behavior, inhibitory effect on cell proliferation, and inhibition of neointimal hyperplasia in vivo. The results demonstrated that an increase in porosity led to a decrease in the mechanical properties of porous NiTi, including hardness, tensile strength, and elastic modulus, and a decrease in the surface cell growth capability, affecting both cell proliferation and morphology. Concurrently, the loading capacity and release duration of rapamycin were extended with increasing porosity, resulting in enhanced inhibitory effects on cell proliferation in vitro and inhibition of neointimal hyperplasia in vivo. In conclusion, porous NiTi holds promise as a desirable vascular drug delivery material, but a balanced consideration of the influence of porosity on both mechanical properties and cytocompatibility is necessary to achieve an optimal balance among drug-loading and release performance, mechanical properties, and cytocompatibility.

Stimuli-responsive polymer-based nanosystems for cardiovascular disease theranostics

Stimulus-responsive polymers have found widespread use in biomedicine due to their ability to alter their own structure in response to various stimuli, including internal factors such as pH, reactive oxygen species (ROS), and enzymes, as well as external factors like light. In the context of atherosclerotic cardiovascular diseases (CVDs), stimulus-response polymers have been extensively employed for the preparation of smart nanocarriers that can deliver therapeutic and diagnostic drugs specifically to inflammatory lesions. Compared with traditional drug delivery systems, stimulus-responsive nanosystems offer higher sensitivity, greater versatility, wider applicability, and enhanced biosafety. Recent research has made significant contributions towards designing stimulus-responsive polymer nanosystems for CVDs diagnosis and treatment. This review summarizes recent advances in this field by classifying stimulus-responsive polymer nanocarriers according to different responsiveness types and describing numerous stimuli relevant to these materials. Additionally, we discuss various applications of stimulus-responsive polymer nanomaterials in CVDs theranostics. We hope that this review will provide valuable insights into optimizing the design of stimulus-response polymers for accelerating their clinical application in diagnosing and treating CVDs.

Association between diabetes mellitus and primary restenosis following endovascular treatment: a comprehensive meta-analysis of randomized controlled trials

IMPORTANCE

Diabetes mellitus (DM) is thought to be closely related to arterial stenotic or occlusive disease caused by atherosclerosis. However, there is still no definitive clinical evidence to confirm that patients with diabetes have a higher risk of restenosis.

OBJECTIVE

This meta-analysis was conducted to determine the effect of DM on restenosis among patients undergoing endovascular treatment, such as percutaneous transluminal angioplasty (PTA) or stenting.

DATA SOURCES AND STUDY SELECTION

The PubMed/Medline, EMBASE and Cochrane Library electronic databases were searched from 01/1990 to 12/2022, without language restrictions. Trials were included if they satisfied the following eligibility criteria: (1) RCTs of patients with or without DM; (2) lesions confined to the coronary arteries or femoral popliteal artery; (3) endovascular treatment via PTA or stenting; and (4) an outcome of restenosis at the target lesion site. The exclusion criteria included the following: (1) greater than 20% of patients lost to follow-up and (2) a secondary restenosis operation.

DATA EXTRACTION AND SYNTHESIS

Two researchers independently screened the titles and abstracts for relevance, obtained full texts of potentially eligible studies, and assessed suitability based on inclusion and exclusion criteria.. Disagreements were resolved through consultation with a third researcher. Treatment effects were measured by relative ratios (RRs) with 95% confidence intervals (CIs) using random effects models. The quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria.

MAIN OUTCOMES AND MEASURES

The main observation endpoint was restenosis, including > 50% stenosis at angiography, or TLR of the primary operation lesion during the follow-up period.

RESULTS

A total of 31,066 patients from 20 RCTs were included. Patients with DM had a higher risk of primary restenosis after endovascular treatment (RR = 1.43, 95% CI: 1.25-1.62; p = 0.001).

CONCLUSIONS AND RELEVANCE

This meta-analysis of all currently available RCTs showed that patients with DM are more prone to primary restenosis after endovascular treatment.

Efficacy and safety of drug-coated balloon for de novo lesions of large coronary arteries: Systematic review and meta-analysis of randomized controlled trials

Background

Drug-coated balloon (DCB) is a novel approach to avoiding stent-related complications and has proven effective for the treatment of in-stent restenosis (ISR) and small vessels. However, its role in the treatment of de novo lesions in large vessels is less settled.

Aims

To estimate the efficacy and safety of drug-coated balloon versus stent in the treatment of de novo lesions in large coronary arteries.

Methods

We searched the literature until April 2023. We judged the safety of DCB based on major adverse cardiovascular events (MACEs), cardiac death, all-cause mortality, non-fatal myocardial infarction, target lesion revascularization (TLR), and bleeding event; and efficacy according to late lumen loss (LLL), minimum lumen diameter (MLD). We conducted subgroup analyses according to stent type and whether urgent PCI was required.

Results

A total of 10 RCTs were included. Overall, LLL (mean difference (MD) = -0.19, 95 % confidence interval (CI): -0.32 to -0.06, P = 0.003) was lower in the DCB group than in the Stent arm. This effect was consistent in subgroup analysis regardless of stent type and disease type. In terms of safety indicators, there were no significant differences between DCB and stent. The subgroup analyses found that safety indicators showed no significant differences between DCB and drug-eluting stent (DES), but TLR was lower in the DCB than in the bare metal stent (BMS). Moreover, in ST-elevation myocardial infarction (STEMI), safety indicators and LLL showed no significant differences between DCB and DES, but MLD in the DCB was smaller. While in patients with excluded STEMI, MACE and TLR was lower in the DCB compared with the overall stent.

Conclusions

DCB could be a promising alternative for treating de novo lesions in large coronary arteries with satisfactory efficacy and low risk, superior to BMS and not inferior to DES, with a trend toward lower late lumen loss.

Drug-coated balloons versus drug-eluting stents in patients with acute myocardial infarction undergoing percutaneous coronary intervention: an updated meta-analysis with trial sequential analysis

BACKGROUND

Drug-coated balloons (DCBs) are an established strategy for coronary artery disease. However, the new generation drug-eluting stent (DES) is recommended for patients with Acute myocardial infarction (AMI) for coronary artery revascularization. Our aim is to provide a comprehensive appraisal of the efficacy of DCBs in patients with AMI undergoing PCI.

METHODS

We searched the WOS, PubMed, Scopus, and Cochrane CENTRAL till March 2023, for studies that compared DCBs versus DES in patients with AMI undergoing PCI. We used a random-effects model to compare major adverse cardiac events (MACE), cardiac death, all-cause death, myocardial infarction, target lesion revascularization (TLR), stent thrombosis, Late lumen Loss (LLL), and minimum lumen diameter (MLD) between the two groups.

RESULTS

Thirteen studies comprising 2644 patients were included. The pooled OR showed non-inferiority of DCB over DES in terms of MACE (OR = 0.89, 95% CI [0.57 to 1.40], p = 0.63). When we defined MACE as a composite of cardiac death, MI, and TLR; the pooled OR favored DCB over DES (OR = 0.50, 95% CI [0.28 to 0.9], p = 0.02). Moreover, DCB was not inferior to DES in terms of all-cause mortality (OR = 0.88, 95% CI: 0.43 to 1.8, p = 0.73), cardiac mortality, (OR = 0.59, 95% CI: 0.22 to 1.56, p = 0.29), MI (OR = 0.88, 95% CI: 0.34 to 2.29, p = 0.79), stent thrombosis (OR = 1.21, 95% CI: 0.35 to 4.23, p = 0.76), TLR (OR = 0.9, 95% CI: 0.43 to 1.93, p = 0.8), LLL (MD = -0.6, 95% CI: -0.3 to 0.19, p = 0.64), or MLD (MD = -0.4, 95% CI: -0.33 to 0.25, p = 0.76).

CONCLUSION

Our meta-analysis indicated that DCB intervention was not inferior to DES in the PCI setting in patients with AMI, and can be recommended as a feasible strategy in AMI.

PROSPERO REGISTRATION

CRD42023412757.

The clinical utility of circulating cell division control 42 in small-vessel coronary artery disease patients undergoing drug-coated balloon treatment

BACKGROUND

Cell division control 42 (CDC42) regulates atherosclerosis, blood lipids, and inflammation and thus affects coronary artery disease (CAD), but its utility in drug-coated balloon (DCB)-treated small-vessel CAD (SV-CAD) patients is unclear. This study intended to evaluate the change and prognostic role of CDC42 in SV-CAD patients underwent DCB.

METHODS

Serum CDC42 was measured by enzyme-linked immunosorbent assay in 211 SV-CAD patients underwent DCB at baseline, day (D) 1, D3, and D7, as well as in 50 healthy controls (HCs).

RESULTS

CDC42 was decreased in SV-CAD patients compared to HCs (P < 0.001), and it was negatively associated with total cholesterol (P = 0.015), low-density lipoprotein cholesterol (P = 0.003), C-reactive protein (P = 0.001), multivessel disease (P = 0.020), and American college of cardiology/American heart association type B2/C lesions (P = 0.039) in SV-CAD patients. Longitudinally, CDC42 decreased from baseline to D1 and then gradually increased to D7 (P < 0.001) in SV-CAD patients after DCB. Interestingly, high CDC42 (cut-off value = 500 pg/mL) at baseline (P = 0.047), D3 (P = 0.046), and D7 (P = 0.008) was associated with a lower accumulating target lesion failure (TLF) rate; high CDC42 at D3 (P = 0.037) and D7 (P = 0.041) was related to a lower accumulating major adverse cardiovascular event (MACE) rate in SV-CAD patients underwent DCB. Importantly, CDC42 at D7 (high vs. low) independently predicted lower accumulating TLF (hazard ratio (HR) = 0.145, P = 0.021) and MACE (HR = 0.295, P = 0.023) risks in SV-CAD patients underwent DCB.

CONCLUSIONS

Circulating CDC42 level relates to milder disease conditions and independently estimates lower risks of TLF and MACE in SV-CAD patients underwent DCB, but further validation is still needed.

Drug-Coated Balloon in Primary Percutaneous Coronary Intervention

According to the latest coronary interventional guidelines, a drug-eluting stent is the recommended reperfusion therapy in primary percutaneous coronary intervention (pPCI). However, deficiencies and defects, such as in-stent restenosis (ISR), incomplete stent apposition, stent thrombosis, reinfarction after stent implantation, long-term dual antiplatelet drug use, and adverse reactions of metal implants, plague clinicians and patients. Drug-coated balloon (DCB), which delivers antiproliferative agents into the vessel wall without stent implantation and leaves no implants behind after the procedure, is a novel option for percutaneous coronary intervention and has proven to be a promising strategy in cases of ISR, small vessel coronary artery disease, and bifurcation lesions. However, most of the available experience has been gained in elective percutaneous coronary intervention, and experience in pPCI is lacking. The current evidence for the use of DCB-only in pPCI was discussed and analyzed in this review.

Lipophilic NO-Driven Nanomotors as Drug Balloon Coating for the Treatment of Atherosclerosis

Drug-coated balloons (DCB) intervention is an important approach for the treatment of atherosclerosis (AS). However, this therapeutic approach has the drawbacks of poor drug retention and penetration at the lesion site. Here, a lipophilic drug-loaded nanomotor as a modified balloon coating for the treatment of AS is reported. First, a lipophilic nanomotor PMA-TPP/PTX loaded with drug PTX and lipophilic triphenylphosphine (TPP) compounds is synthesized. The PMA-TPP/PTX nanomotors use nitric oxide (NO) as the driving force, which is produced from the reaction between arginine on the motor substrate and excess reactive oxygen species (ROS) and inducible nitric oxide synthase (iNOS) in the AS microenvironment. The final in vitro and in vivo experimental results confirm that the introduction of the lipophilic drug-loaded nanomotor technology can greatly enhance the drug retention and permeability in atherosclerotic lesions. In particular, NO can also play an anti-AS role in improving endothelial cell function and reducing oxidative stress. The chemotherapeutic drug PTX loaded onto the nanomotors can inhibit cell division and proliferation, thereby exerting the effect of inhibiting vascular intimal hyperplasia, which is helpful for the multiple therapies of AS. Using nanomotor technology to solve cardiovascular diseases may be a promising research direction.

The factors influencing the efficiency of drug-coated balloons

The drug-coated balloon (DCB) is an emerging percutaneous coronary intervention (PCI) device that delivers drugs to diseased vessels to decrease the rate of vascular stenosis. Recent clinical studies have demonstrated that DCBs tend to have both good safety and efficacy profiles, leading to extended application indications in the clinic, including in-stent restenosis (ISR) for metal stents such as drug-eluting stents (DESs), small vascular disease, bifurcation disease, large vascular disease, acute coronary syndrome (ACS), and high bleeding risk. However, some previous clinical data have suggested that DCBs performed less effectively than DESs. No studies or reviews have systematically discussed the improvement strategies for better DCB performance until now. Drug loss during the process of delivery to the target lesion and inefficient delivery of the coating drug to the diseased vascular wall are two key mechanisms that weaken the efficiency of DCBs. This review is the first to summarize the key influencing factors of DCB efficiency in terms of balloon structure and principles, and then it analyzes how these factors cause outcomes in practice based on current clinical trial studies of DCBs in the treatment of different types of lesions. We also provide some recommendations for improving DCBs to contribute to better DCB performance by improving the design of DCBs and combining other factors in clinical practice.

Appropriate Surrogate Endpoint in Drug-Coated Balloon Trials for Coronary Artery Diseases

Background

The appropriateness of using late lumen loss (LLL) as a surrogate endpoint was established in drug-eluting stent (DES) studies, but it was less supportive for drug-coated balloon (DCB) trials.

Methods

Studies published until 23 June 2021 were searched from PubMed, EMBASE, Cochrane Library, and ClinicalTrials.gov. The correlation between LLL, MLD (minimal lumen diameter), and %DS (percentage diameter stenosis) and clinical endpoints was evaluated by linear regression. Standardized effect size and its 95% CIs were used to illustrate the difference among LLL, MLD, and %DS.

Results

A total of 24 clinical trials were eligible [16 DCB vs. DES, 7 DCB vs. plain old balloon angioplasty (POBA), and 1 DCB vs. DES vs. POBA]. Thirteen (54.2%) trials used LLL as the primary endpoint. LLL, MLD, and %DS all had significant associations with clinical endpoints. For DCB vs. DES trials, the number of studies that reported inconsistent results between LLL and MLD was 12/16 (75.0%) and between LLL and %DS was 10/15 (66.7%), while in MLD and %DS, it was 1/16 (6.3%). The difference of standardized effect size between LLL and MLD was −0.47 (95% CI, −0.69 to −0.25, p < 0.001) and LLL and %DS was−0.31 (95%CI,−0.43 to−0.20, p < 0.001) while in MLD and %DS, there was no difference, 0.1 (95%CI,−0.02 to 0.22, p = 0.084).

Conclusions

For DCB trials, an appropriate surrogate is associated with the control device. The traditional LLL could be used in the DCB vs. POBA trials. However, MLD/%DS should be considered a more suitable surrogate endpoint when comparing DCB with DES.

Efficacy and safety of drug-coated balloon in the treatment of acute myocardial infarction: a meta-analysis of randomized controlled trials

Acute myocardial infarction (AMI) is one of the main causes of death in the world, and the incidence of AMI is increasing in the young population. Drug-coated balloon (DCB) has become an effective concept for the treatment of in-stent restenosis, small vessel disease, bifurcation lesions, high blood risk conditions, and even de novo large vessel disease. To ensure whether DCB can play an alternative role in AMI, we conducted a comprehensive meta‐analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of DCB in the treatment of AMI. Electronic databases were searched for RCTs that compared DCB with stent for AMI. The primary outcome was major adverse cardiac events (MACEs), the secondary outcome was late lumen loss (LLL). RevMan 5.3 software and RStudio software were used for data analysis. Five RCTs involving 528 patients with 6–12 months of follow-up were included. There was no significant difference in the incidence of MACEs between DCB group and stent group (RR, 0.85; 95% CI 0.42 to 1.74; P = 0.66). Lower LLL was shown in DCB group (WMD, − 0.29; 95% CI − 0.46 to − 0.12; P < 0.001). This meta-analysis of RCT showed that DCB might provide a promising way on AMI compared with stents. Rigorous patients’ selection and adequate predilation of culprit lesions are necessary to optimize results and prevent bailout stent implantation.

PROSPERO registration number: CRD42020214333.

Drug Eluting Devices in the Urinary Tract

The obstruction of the upper urinary tract represents a common medical condition which could be related to significant and life-threating complications such acute renal failure and urosepsis. Ureteral stents are commonly used to prevent and manage such complications. However, the use of standard stents involves significant comorbidities, including stent-associated infection, encrustation, migration, urothelial hyperplasia reaction. Also, urethral strictures represent a common cause of lower urinary tract obstruction with the characteristic of frequent recurrence. Patients suffering from urethral strictures can be treated by minimally invasive techniques such as mechanical dilatation with balloon or placing of urethral stents. In attempt to address the any stent-related complications, the urological research considered ideas and concepts used in interventional cardiology and radiology. Percutaneous transluminal coronary angioplasty (PTCA) is the gold standard for coronary revascularization, even if restenosis complications exist in concerning rates. To address this complication, stents bearing drugs agents (most commonly immunosuppressive agents) have been used. These drug-eluting stents (DESs) release single or multiple bioactive agents, which are deposited on adjacent tissues. The immunosuppressive substances reduce benign tissue proliferation and their use has significantly reduced restenosis rates after PTCA. In a similar fashion, the drug-coated balloons (DCBs) are used as a new alternative instead of DESs in selected cases and offer important advantages. Their drug is released directly at the site of the stricture while avoiding any foreign material at the site of the stricture. Unfortunately, possibility of using DCBs in endourology is also under research.

Drug-Coated Balloon vs. Stent for de novo Non-small Coronary Artery Disease: A Systematic Review and Meta-Analysis

Introduction: Drug-coated balloon (DCB) has been an attractive option in de novo vessels. A systematic review and meta-analysis were conducted to evaluate the efficacy and safety of DCB vs. stent for treating de novo lesions in non-small vessels.

Methods: Studies in PubMed, Embase, the Cochrane Central Register of Controlled Trials, and Web of Science were searched (from their commencement to March 2021). This meta-analysis was performed by Review Manager 5.3.

Results: A total of 3 random controlled trials (RCTs) with 255 patients and 2 observational studies (OS) with 265 patients were included in this meta-analysis following our inclusion criteria. It could be observed that DCB presented no significant difference in cardiac death (CD) (RR 0.33, 95% CI [0.01, 8.29], p = 0.50 in OS), myocardial infarction (MI) (RR 0.49, 95% CI [0.09, 2.50], p = 0.39 in RCT), target lesion revascularization (TLR) (RR 0.64, 95% CI [0.19, 2.18], p = 0.47 in RCT) (RR 1.72, 95% CI [0.56, 5.26], p = 0.34 in OS), and late lumen loss (LLL) (SMD −0.48, 95% CI [−1.32, 0.36], p = 0.26 in RCT) for de novo non-small coronary artery disease (CAD) compared with stents, whereas minimal lumen diameter (MLD) including MLD1 (SMD −0.67, 95% CI [−0.92 −0.42], p < 0.00001 in RCT) and MLD2 (SMD −0.36, 95% CI [−0.61 −0.11], p = 0.004 in RCT) was smaller in DCB group.

Conclusion: This systematic review showed that DCB might provide a promising way on de novo non-small coronary artery disease compared with stents. However, more RCTs are still needed to further prove the benefits of the DCB strategy.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/#recordDetails.

Duration of Dual Antiplatelet Therapy After Implantation of Drug-Coated Balloon

The drug-coated balloon (DCB) is an emerging percutaneous coronary intervention (PCI) device with theoretical advantages and promising results. Recent clinical observations have demonstrated that DCB tends to have both good efficacy and a good safety profile in the treatment of in-stent restenosis (ISR) for both bare-metal and drug-eluting stents (DES), de novo coronary artery disease (CAD), and other situation, such as high bleeding risk, chronic total occlusion, and acute coronary syndrome (ACS). Dual antiplatelet therapy (DAPT) has become an essential medication in daily clinical practice, but the optimal duration of DAPT after the implantation of a DCB remains unknown. At the time of the first in vivo implantation of paclitaxel-DCB for the treatment of ISR in 2006, the protocol-defined DAPT duration was only 1 month. Subsequently, DAPT duration ranging from 1 to 12 months has been recommended by various trials. However, there have been no randomized controlled trials (RCTs) on the optimal duration of DAPT after DCB angioplasty. Current clinical guidelines normally recommend the duration of DAPT after DCB-only angioplasty based on data from RCTs on the optimal duration of DAPT after stenting. In this review, we summarized current clinical trials on DCB-only angioplasty for different types of CADs and their stipulated durations of DAPT, and compared their clinical results such as restenosis, target lesion revascularization (TLR) and stent thrombosis event. We hope this review can assist clinicians in making reasonable decisions about the duration of DAPT after DCB implantation.

Intracoronary Imaging Versus Coronary Angiography to Guide Drug-Coated Balloon Intervention in Coronary Artery Disease: A Propensity-Matched Pilot Study Analysis

Limited data exist about the effect of intracoronary imaging (ICI)-guided drug-coated balloon (DCB) intervention on clinical end points. In all, 1157 patients with coronary artery disease treated with DCB between December 2014 and December 2017 at Beijing Anzhen Hospital were included in the final analysis in this cohort study. The primary end point was the incidence of target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction (MI), and target lesion revascularization, and the key secondary end point was the incidence of cardiac death or target vessel MI. The median follow-up for clinical events was 32.0 months (IQR 25.0-40.0). Intracoronary imaging was used in 90 (7.8%) patients. There was no statistically significant difference in TLF (12.2% vs 12.5%, P = .80) between ICI-guided and angiography-guided group. Cardiac death or target vessel MI rates (1.1% vs 3.7%, P = .17) were numerically lower for the ICI-guided cohort. In the propensity score-based analysis, TLF (10.5% vs 16.2%, P = .19) and cardiac death or target vessel MI rates (1.2% vs 2.3%, P = .51) tended to be lower for the ICI-guided cohort. In this observational study, TLF rate tended to decrease in the ICI-guided DCB treatment group compared with angiography-guided procedures. Larger studies are needed.

Drug-Coated Balloon versus Drug-Eluting Stent in Patients with Small-Vessel Coronary Artery Disease: A Meta-Analysis of Randomized Controlled Trials

Background

Percutaneous coronary intervention (PCI) with drug-eluting stents (DES) of small-vessel coronary artery disease (SVD) is related to an increased risk of in-stent restenosis (ISR) and stent thrombosis (ST). The application of the drug-coated balloon (DCB) for patients with SVD remains controversial.

Objectives

Assess the outcomes of DCB in the treatment of SVD compared with DES in patients with SVD.

Methods

A meta-analysis of randomized controlled trials (RCTs) published up to June 2020, reporting the outcomes of DCB versus DES in the treatment of SVD, was performed.

Results

Four RCTs with 1227 patients were included. The results indicated that DCB was associated with the decreased risk for myocardial infarction (MI) compared with the DES, but the difference showed no significance (OR 0.50, 95% CI 0.24-1.03, P=0.06). And, there was no significant difference in death (OR 0.76, 95% CI 0.17-3.43, P=0.72), cardiac death (OR 1.92, 95% CI 0.74-4.98, P=0.18), target vessel revascularization (TVR) (OR 0.81, 95% CI 0.51-1.28, P=0.36), target lesion revascularization (TLR) (OR 1.29, 95% CI 0.66-2.52, P=0.46), and major adverse cardiac events (MACE) (OR 0.92, 95% CI 0.61-1.38, P=0.69) between the DCB group and DES group.

Conclusion

Compared with DES, DCB was associated with a decreased risk of MI among patients with SVD, but the difference showed no significance. The application of DCB in SVD is associated with comparable outcomes of death, TVR, and MACE when compared with DES.

Drug-delivering devices in the urinary tract: A systematic review

Objective

: To systematically review the use of drug-eluting stents (DES) and drug-coated balloons (DCB) in urology.

Materials and Methods

The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, Scopus, Web of science and Cochrane Library online databases were searched in February 2019. Experimental and clinical studies, which included the placement of a DES or dilatation with DCB for investigating their potential use in the urinary tract for the management of ureteric or urethral pathologies, were included. The primary endpoint was to evaluate the current use of DES and DCB in urology.

Results

A total of 29 articles were included in the systematic review. A total of 10 studies tested DES or DCB containing anti-proliferative agents (paclitaxel, zotarolimus, sirolimus, halofugione). Antibiotic agent-containing DES were tested in nine studies (triclosan, quinolones, teicoplanin, nitrofurantoin, silver sulfadiazine). A total of eight studies investigated the release of anti-inflammatory agents by DES (ketorolac, indomethacin, EW-7197). Another group studied heparin-eluting stents.

Conclusion

Despite the inconclusive outcomes of the three randomised controlled trials, drug-coated/eluting devices constitute a promising field in urology for the prevention of complications associated with conventional stents including pain and encrustation. Pre-clinical in vitro and in vivo studies have shown their ability to mitigate inflammation, inhibit re-stenosis and improve pain as indicated by declined use of anti-inflammatory drugs.

Abbreviations: DES: drug-eluting stents; DCB: drug-coated balloons; DCS: drug-coated stents; HF: halofungione; MCP-1: monocyte chemoattractant protein 1; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses; PTCA: percutaneous transluminal coronary angioplasty; RANTES: regulated on activation, normal T-cell expressed and secreted; RCT: randomised controlled trial; USSQ, Ureteric Stent Symptoms Questionaire.

Short- and long-term functional results following drug-coated balloons versus drug- eluting stents in small coronary vessels: The RESTORE quantitative flow ratio study

Background Immediate and long-term functional outcomes after percutaneous treatment of small vessel disease (SVD) with drug-coated balloon (DCB) versus drug-eluting stent (DES) remain unknown. The study sought to investigate whether treatment of de novo SVD with DCB yields similar functional results compared with DES, as judged with angiography-based quantitative flow ratio (QFR). Methods and results QFR was measured at pre-procedural, post-procedural and 9-month angiography in all available subjects from the non-inferiority RESTORE SVD China trial, in which patients were randomized to Restore DCB (n = 116) or Resolute DES (n = 114) study arms. Primary outcome of this analysis was 9-month QFR. Pre-procedural, post-procedural and 9-month QFR was performed in 84.8% (195/230), 83.0% (191/230) and 93.8% (181/193) cases, respectively. At 9 months, the QFR of DCB showed no significant difference to DES (0.88 ± 0.23 vs. 0.92 ± 0.12, p = 0.12). Both 9-month QFR and the QFR difference between post-procedure and 9-month follow-up were correlated with angiographic percentage of diameter stenosis and late loss, and predictive of 2-year clinical outcome. Conclusions Treatment of coronary SVD with DCB resulted in similar 9-month functional results compared with DES. This study provides evidences to the value of QFR as a mean of evaluating device performance after coronary revascularization. Clinical trial registration URL: https://www.clinicaltrials.gov; ClinicalTrial.gov: Identifier: NCT02946307.

Drug coated balloons and their role in bifurcation coronary angioplasty: appraisal of the current evidence and future directions

INTRODUCTION

Coronary Bifurcation lesions are technically more challenging and Bifurcation percutaneous coronary intervention (PCI) remains a challenge with unpredictable and sub-optimal clinical and angiographic results. Drug-Coated Balloons (DCB) are emerging devices in the field of coronary intervention with promising results that may overcome some of drug eluting stents limitations and may have potential advantages in complex bifurcation PCI.

AREAS COVERED

We have performed a re-appraisal about the issues with current bifurcation PCI techniques and the use of DCB in the treatment of Bifurcation lesions. Several studies performed utilizing DCB are described and critically appraised. Over the recent years, there have been tremendous developments in the DCB technology, lesion preparation, clinical experience, and clinical data during bifurcation PCI. The current review describes the advances in the DCB technology, pharmacokinetics, role of excipients, and optimization of the technique. Special emphasis in lesion preparation and potential pathway of using DCB in bifurcation PCI is proposed.

EXPERT OPINION

Although different proof of concept and pilot studies have shown promising results in treatment of bifurcation lesions with DCB, larger randomized trials and/or international consensus papers are required to enable worldwide translation of this idea to clinical practice.

Small vessel coronary artery disease: How small can we go with myocardial revascularization?

The issue of small coronary artery atherosclerosis represents an intriguing aspect of coronary artery disease, which is related with higher rates of peri- and post-procedural complications and impaired long-term outcome. This problem is further complicated by the unclear definition of small coronary vessel. Recent randomized controlled trials have provided new data on possible novel interventional treatment of small coronary vessels with drug-coated balloons instead of traditional new-generation drug-eluting stent implantation. Also, the conservative management represents a therapeutic option in light of the results of the recent ISCHEMIA trial. The current article provides an overview of the most appropriate definition, interventional management, and prognosis of small coronary artery atherosclerosis.