Five-year clinical outcomes of a polymer-free sirolimus-eluting stent versus a permanent polymer paclitaxel-eluting stent: Final results of the intracoronary stenting and angiographic restenosis - test equivalence between two drug-eluting stents (ISAR-TES

Polymer-free stents for percutaneous coronary intervention in diabetic patients: a systematic review and meta-analysis

Aim: To compare the efficacy of polymer-free drug-eluting stents (PF-DES) versus other stents in diabetic patients with coronary artery disease undergoing percutaneous coronary interventions. Materials & methods: A systematic review and meta-analysis were performed to identify pertinent randomized controlled trials. The primary end point was the occurrence of target lesion failure. Results: Eight randomized controlled trials were included for a total of 4854 subjects. The PF-DES group experienced a trend in favor of a lower rate of target lesion failure (Incidence rate ratio = 0.91; p = 0.11) and a significantly lower rate of cardiac mortality, as compared with the control group (Incidence rate ratio = 0.82; p = 0.04). However, statistical significance was lost if bare-metal stent patients were excluded and a trend in favor of the PF-DES strategy was reported only for cardiac mortality. Conclusion: PF-DES could be a valuable strategy in diabetic patients with coronary artery disease undergoing percutaneous coronary interventions.

Individualizing Medicinal Therapy Post Heart Stent Implantation: Tailoring for Patient Factors

The field of cardiovascular medicine is undergoing a transformative shift towards personalized medicinal therapy, particularly in the context of post stent implantation. This narrative review explores the significance, challenges, and future directions of individualized treatment strategies for patients with coronary stents. The review highlights the pivotal role of personalized approaches in optimizing treatment efficacy and minimizing adverse events. Real-world clinical studies and trials underscore the importance of tailoring antiplatelet therapy based on platelet function testing, genetic testing, and risk scoring. These studies reveal that personalized medicinal treatment improves clinical outcomes by balancing preventing thrombotic events and mitigating bleeding risks. Challenges, including cost, test availability, patient adherence, and ethical considerations, are discussed in depth, shedding light on the complexities of implementing personalized approaches. Technological advancements, including omics data integration, artificial intelligence, and big data analytics, shape the future of personalized medicinal therapy. These tools enable precise pharmacogenomic selection of medications and the development of integrated risk-scoring systems. Patient engagement and education are also central, with empowered patients and remote monitoring contributing to collaborative decision-making. In conclusion, the narrative review underscores that personalized medicinal therapy post stent implantation holds immense promise for revolutionizing cardiovascular care. By embracing a comprehensive approach that considers genetics, clinical factors, and patient preferences, healthcare providers can optimize treatment outcomes and improve patient quality of life. The evolving landscape of personalized medicine offers a glimpse into a future where tailored treatment strategies become the cornerstone of precision cardiovascular care.

Clinical Outcomes of Polymer-Free Versus Polymer-Coated Drug-Eluting Stents in Patients With Coronary Artery Disease: A Systematic Review and Meta-Analysis

Drug-eluting stents have transformed the treatment of coronary artery disease (CAD), and there are two types: polymer-free and polymer-coated stents. Polymer-free stents have a coating that is quickly absorbed by the body, whereas polymer-coated stents have a coating that remains on the stent surface. This meta-analysis and systematic review aimed to compare the clinical outcomes of these two stent types in patients with coronary artery disease. The literature and abstracts from significant databases were reviewed to compare polymer-free drug-eluting stents (PF-DES) and polymer-coated drug-eluting stents (PC-DES) for the treatment of coronary artery disease (CAD). The primary efficacy endpoints of the study were all-cause mortality and deaths from cardiovascular and non-cardiovascular causes. Among the secondary outcomes were incidences of myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), stent thrombosis, stroke, and major adverse cardiovascular events (MACEs). In terms of the primary outcomes, the combined analysis revealed a marginally lower risk of all-cause mortality (relative risk, RR (95% CI) = 0.92 (0.85, 1.00), p = 0.05, I² = 0%) with the use of PF-DES versus PC-DES. Nonetheless, there was no significant difference in cardiovascular mortality (RR (95% CI) = 0.97 (0.87, 1.08)) or non-cardiovascular mortality (RR (95% CI) = 0.87 (0.69, 1.10), p = 0.25, I² = 9%) between the groups. Furthermore, univariate meta-regression revealed that male gender and prior myocardial infarction were independently associated with an increased risk of all-cause mortality and cardiovascular disease. According to the current meta-analysis, no statistically significant differences existed in PF-DES and PC-DES outcomes. More extensive research is needed to investigate these findings further and establish their validity.

Drug-eluting stents for the treatment of coronary artery disease: A review of recent advances

INTRODUCTION

Percutaneous coronary intervention is a widely used procedure for the treatment of coronary artery disease to relieve narrowing or occlusion and improve blood supply. Although only balloon angioplasty was performed in the early period, coronary stents were developed later and coronary drug-eluting stents were introduced to decrease in-stent restenosis, which is related to the proliferation and migration of vascular smooth muscle cells.

AREAS COVERED

The drug-eluting stents are composed of a metallic or polymeric platform, specific drug, and polymers or coating for drug release. In this article, the recent advances in drug-eluting stent technologies for the treatment of coronary artery disease and adjunctive antiplatelet therapy after drug-eluting stent implantation will be reviewed.

EXPERT OPINION

The need for further advances in drug-eluting stents or fully bioresorbable coronary scaffolds still exists to improve patient survival or clinical outcomes. The use for different actions or of combinations of drugs with several actions can be potential. Technological refinement and progress in manufacturing to improve mechanical integrity are needed, particularly for fully bioresorbable scaffolds. For antiplatelet therapy after stenting, clinical bleeding reduction strategies, such as a shortened duration of dual-antiplatelet therapy, are in progress.

Safety and efficacy of the polymer-free and polymer-coated drug-eluting stents in patients undergoing percutaneous coronary intervention

INTRODUCTION

The relative safety and efficacy of polymer-free (PF) versus polymer-coated (PC) drug-eluting stents (DES) in patients with angina or acute coronary syndrome (ACS) undergoing percutaneous coronary intervention has received limited study.

METHOD

Digital databases were queried to identify relevant studies. Major adverse cardiovascular events (MACE) and secondary outcomes were compared using a random effect model to calculate unadjusted odds ratios (OR).

RESULTS

A total of 28 studies consisting of 23,198 patients were included in the final analysis. On pooled analysis, there was no significant difference in the odds of MACE (OR 0.98, 95% CI 0.91-1.08) and major bleeding (OR 0.87, 95% CI 0.61-1.24) between patients undergoing PF-DES versus PC-DES. Similarly, the odds of myocardial infarction, stroke, stent thrombosis, cardiovascular mortality and need for target vessel revascularization was similar between the two groups. PF-DES was favored due to significantly lower odds of non-cardiac death (OR 0.78, 95% CI 0.68-89) and all-cause mortality (OR 0.87, 95% CI 0.80-0.95), but had a higher need for target lesion revascularization (OR 1.2, 95% CI 1.02-1.42). A subgroup analysis based on follow up duration, clinical presentation, presence of diabetes and class of eluting drugs mirrored the net estimates for all outcomes with a few exceptions. A sensitivity and meta-regression analysis showed no influence of single-study and duration of antiplatelet therapy on pooled outcomes.

CONCLUSION

In patients presenting with angina or ACS, PF-DES might be favored due to lower all-cause mortality and equal risk of ischemic adverse cardiovascular and major bleeding events compared with PC-DES.

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.

Polymer-Free vs. Polymer-Coated Drug-Eluting Stents for the Treatment of Coronary Artery Disease: A Meta-Analysis of 16 Randomized Trials

BACKGROUND

Polymer-coating represents one of components of drug-eluting stents (DES) to have experienced a more intensive technological evolution. Polymer-free DES (PF-DES) have offered promising angiographic results, with earlier complete re-endothelization, potentially reducing the thrombotic risk and offering the option of a shorter antiplatelet therapy. However, contrasting prognostic data have been reported so far with PF-DES. Therefore, the aim of the present study was to perform a comprehensive updated meta-analysis of randomized trials (RCT) comparing the impact of PF-DES vs polymer- coated DES (PC-DES) on clinical outcome.

METHODS

Literature and main scientific session abstracts were searched for RCTs comparing PF-DES vs PC-DES for the treatment of CAD. The primary efficacy endpoint was mortality, secondary endpoints were cardiovascular death, myocardial infarction, target lesion revascularization (TLR) and stent thrombosis.

RESULTS

We included 16 randomized clinical trials, with a total of 15,689 patients, including 50.6% randomized to PF-DES. At a median follow-up of 24 months, PF-DES were associated to a significant reduction in mortality as compared to PC-DES (0.82 [0.68, 0.99], p = .03, I2 = 0%; phet = 0.93). However, no significant benefit was observed in terms of cardiovascular death or major ischemic endpoints (respectively CV death: OR [95% CI] = 0.92 [0.71, 1.18] p = .50, I2 = 0.50; phet = 0.84; MI: OR [95% CI] = 1.08 [0.90, 1.29], p = .42; I2 = 0%, phet = 0.98; TLR: OR [95% CI] = 1.02 [0.78, 1.32], p = .91; I2 = 0.63 phet = 0.0003; ST: OR [95% CI] = 0.98 [0.87, 1.10], p = .72; I2 = 0% phet = 0.64). By meta-regression analysis, the mortality benefits of PF-DES were not conditioned by the rate of diabetes mellitus or acute coronary syndromes.

CONCLUSIONS

Based on the current meta-analysis, PF-DES are associated to a significant reduction in mortality as compared to PC-DES, but not in the occurrence of major ischemic events. Future larger studies are certainly needed to further investigate and confirm our findings, especially in particular subsets of patients, such as those with high bleeding risk or acute myocardial infarction.

Polymer-free drug-eluting stents versus permanent polymer drug-eluting stents: An updated meta-analysis

BACKGROUND

Polymer-free drug-eluting stents (PF-DES) have been demonstrated comparable to permanent polymer drug-eluting stents (PP-DES) during long-term follow-up. As a critical component of drug-eluting stents, antiproliferative drugs may be a confounding factor for the results. Thus, we sought to compare the outcomes of these stents during long-term follow-up, especially in consideration of different stent platforms with the same drugs.

METHODS

A systemic search was performed to identify the related randomized controlled trials comparing PF-DES with PP-DES. Primary outcomes included short (≤1 year) and long-term (>1 year) target lesion revascularization (TLR), short-term in-stent late luminal loss (LLL) and diameter stenosis (DS). Subgroup analyses stratified by the different platforms with the same proliferative drugs were conducted in TLR, LLL, and DS. Standardized mean differences (SMDs) and risk ratios (RRs) were estimated using fixed /random effects models RESULTS:: A total of 6927 patients extracted from 12 RCTs were enrolled in the meta-analysis. No differences were observed in clinical outcomes of short-term and long-term overall mortality, myocardial infarction and stent thrombosis and angiographic outcomes of short-term in-stent LLL and DS between PF-DES and PP-DES for patients with coronary artery lesions. Nevertheless, compared with PP-DES coated with the same proliferative drugs, PF-DES had significantly increased risks of in-stent LLL (SMD, 0.49; 95% confidence interval [CI], 0.25-0.72) and DS (SMD, 0.67; 95% CI, 0.27-1.07), and long-term TLR (RR, 1.64; 95% CI 1.13-2.39). There were no significant differences in other outcomes.

CONCLUSIONS

Under the condition of using same antiproliferative drugs (paclitaxel or sirolimus) in different stent systems, PF-DES are associated with the increased risk of restenosis compared to PP-DES.

Outcomes of the amphilimus-eluting polymer-free stent for chronic total occlusion treatment: a multicentre experience

AIMS

Late stent thrombosis and delayed vessel wall healing remain an important issue in coronary vessels treated with drug-eluting stents (DES), especially when long-vessel segments need to be covered, like in chronic total occlusions (CTO). Avoiding polymer use to avoid chronic inflammatory responses is a potential solution to reduce target vessel failure (TVF). We aimed to validate the clinical safety and efficacy at 1 year of the polymer-free Cre8 DES vs. nonpolymer-free DES for the percutaneous treatment of CTO.

METHODS

Between September 2011 and August 2016, patients were prospectively enrolled in three CTO centres. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE), including cardiac death, any myocardial infarction, stent thrombosis, TVF and target vessel revascularization.

RESULTS

A total of 102 Cre8 and 133 non-Cre8 patients were enrolled. At 1 year, a low cumulative MACCE was observed in the Cre8 group (6.9%, respectively). Moreover, a numerical trend towards better MACCE was observed in the Cre8 group vs. the non-Cre8 group (6.9 vs. 14.3%; P = 0.065). The clinically driven TVF rate was not statistically different between Cre8 and non-Cre8 patients (6.9 vs. 9.8%; P = 0.373). A borderline significant difference regarding mortality was observed in favour of Cre8 patients (0 vs. 3.8%; P = 0.049).

CONCLUSION

Low rates of MACCE and TVF up to 1 year were observed in the Cre8 group, supportive of the use of polymer-free DES for lesions with high complexity.

Polymer-free versus durable polymer drug-eluting stents in patients with coronary artery disease: A meta-analysis

Background

Polymer-free drug-eluting stents (PF-DES) were introduced with the aim of reducing the risk of stent thrombosis associated with durable polymer drug-eluting stents (DP-DES). The comparison of safety and efficacy profiles between these two stent platforms remains unclear.

Materials and methods

We conducted electronic database searches for randomized controlled trials (RCTs) comparing patients treated with either PF-DES or DP-DES. Outcomes included definite or probable stent thrombosis (ST), myocardial infarction (MI), cardiac death, all-cause death, target lesion revascularization (TLR), and target vessel revascularization (TVR). A random-effects model was used to derive risk ratios (RRs) with 95% confidence intervals (CIs). Subgroup analyses based on different variables were also performed. After screening a total of 1026 articles, the present meta-analysis included 13 RCTs comprising 8021 patients.

Results

No significant differences were found for the risks of definite or probable ST (RR, 0.94; 95% CI, 0.62–1.43; P = 0.77), MI (RR, 1.06; 95% CI, 0.85–1.33; P = 0.61), cardiac death (RR, 0.98; 95% CI, 0.80–1.21; P = 0.88), all-cause death (RR, 0.87; 95% CI, 0.76–1.00; P = 0.06), TLR (RR, 1.12; 95% CI, 0.94–1.33; P = 0.22), and TVR (RR, 1.18; 95% CI, 0.87–1.61; P = 0.29). Similarly, no significant differences were found for all outcomes regardless of anti-proliferative drug, except for an increased risk of TLR for polymer-free paclitaxel-eluting stents compared with DP-DES (RR, 2.32, 95% CI, 1.30–4.14; P = 0.005).

Conclusions

Our findings showed that PF-DES and DP-DES confer equivalent safety and efficacy profiles, with similar rates of stent thrombosis.

•

Polymer-free and durable polymer drug-eluting stents confer similar safety and efficacy profiles.

•

There were comparable rates of stent thrombosis between the two stent platforms.

•

Further trials with greater length of follow-up are warranted to assess long-term safety and efficacy outcomes.

Polymer-free dual drug-eluting stents evaluated in a porcine model

BACKGROUND

Although drug-eluting stents have dramatically reduced the rates of restenosis and target lesion revascularization, they are associated with stent thrombosis (ST), a catastrophic event likely due to delayed endothelialization and chronic inflammation caused by the polymer and the metal scaffolds. To increase the safety and efficacy of stents, polymer-free dual drug-eluting stents (DDES) have been developed.

METHODS

A total 160 stents (Bare-metal stents (BMS), polymer-free probucol stents (PrES), sirolimus-eluting stents (SES) and DDES) were randomly implanted in the coronary arteries of 80 pigs. 14, 28, 90 and 191 days after implantation, QCA and OCT evaluations were performed in 20 pigs respectively, and the arteries were harvested for scanning electron microscope (SEM), histomorphology, histopathology analyses and for the relative expression of CD31, CD34 and CD133 on mRNA and protein levels.

RESULTS

At the 14-day time point, there were significant differences in the strut rate coverage (p = 0.011), with greater coverage in the PrES than in the SES group (53.2%vs. 20.3%, p = 0.002). As well, there were no significant differences in the expression of CD31, CD34 and CD133 between groups in mRNA and protein level.

CONCLUSIONS

DDES were as safe as BMS and SES, but they did not further improve the endothelialization of the stented coronary arteries in the porcine model.

Efficacy and safety of polymer-free stent versus polymer-permanent drug-eluting stent in patients with acute coronary syndrome: a meta-analysis of randomized control trials

BACKGROUND

The efficacy and safety of polymer-free stent (PFS) versus permanent polymer drug-eluting stent (PPDES) in patients undergoing percutaneous coronary intervention (PCI) remain controversial. Our meta-analysis was undertaken to evaluate and compare the efficacy and safety of PFS with those of PPDES in patients undergoing PCI.

METHODS

We searched PubMed, Cochrane Library, EMBASE, and Clinical Trials.gov databases for randomized controlled trials (RCTs). The primary endpoints were incidence of stent thrombosis (ST) and target-lesion revascularization (TLR). The secondary endpoints included the incidence of major adverse cardiovascular events (MACE), myocardial infarction (MI), cardiac death (CD), late lumen loss (LLL), and diameter stenosis (DS). Subgroup analyses were also conducted based on the follow-up time.

RESULTS

Eleven RCTs met the including criteria, and 8616 patients were included in the study. No significant differences were observed between PFS and PPDES treatments in the incidence of ST (RR 0.90; 95% CI: 0.62-1.31; P = 0.58; I ²  = 0), TLR (RR 0.87; 95% CI: 0.76-1.00; P = 0.05; I ²  = 37%), CD (RR 0.89; 95% CI: 0.72-1.10; P = 0.28; I ²  = 0), MI (RR 0.87; 95% CI: 0.71-1.05; P = 0.15; I ²  = 0), LLL (SMD 0.01; 95% CI: -0.29-0.30; P = 0.96; I² = 90%), and DS (SMD -0.01; 95% CI: - 0.25 to 0.23; P = 0.93; I² = 83%). Meanwhile, the patients with PFS had a lower incidence of MACE (RR 0.87; 95% CI: 0.78-0.97; P = 0.01; I ²  = 0) than those with PPDES.

CONCLUSION

In the overall analysis, patients with PFS presented a lower risk of MACE versus PPDES, but no significant difference were obtained in the risk of ST, TLR, MI, CD, DDD and DS. In the Short term follow up, patients with PSF presented a lower risk of TLR compared with PPDES.

Three-Year Clinical Outcomes of a Polymer-Free Paclitaxel-Eluting Microporous Stent in Real-World Practice: Final Results of the Safety and Efficacy Registry of the Yinyi Stent (SERY-I)

BACKGROUND

The safety and efficacy of a China-made polymer-free paclitaxel-eluting microporous stent (Yinyi) at 1-year has been previously reported. However, limited evidence exists regarding the long-term performance of this novel drug-eluting stent (DES). This study investigated the 3-year efficacy and safety of the Yinyi stent in the setting of safety and efficacy registry of the Yinyi stent (SERY-I) clinical trial.

METHODS

Between June 2008 and August 2009, a total of 1045 patients undergoing percutaneous coronary intervention (PCI) were implanted with ≥ 1 Yinyi stents at 27 medical centers in mainland China. Thereafter, clinical follow-up was performed for a period of 3 years after enrollment. The primary endpoint was the cumulative rate of composite major adverse cardiac events (MACE) including target lesion revascularization (TLR), the combined incidence of cardiac death, and non-fatal myocardial infarction; the second endpoint was the incidence of stent thrombosis.

RESULTS

Overall, 1376 lesions were treated successfully with 1713 Yinyi stents, and 1019 (98.7%) patients received dual antiplatelet therapy for at least 12 months. At 3 years, a total of 13 (1.33%) patients had suffered cardiac death. The incidence of non-fatal myocardial infarction and TLR was 9 (0.92%) and 58 (5.92%) among the patients. Stent thrombosis occurred in 13 (1.33%) patients, and the rate of Academic Research Consortium (ARC) definite or probable stent thrombosis was 0.82%.

CONCLUSIONS

Given the limitations that SERY-I was a single arm, nonrandomized study and only telephone follow-up was performed without angiographic analysis, the safety and efficacy of Yinyi stent observed in this extended follow-up Registry needs further verification.

Long-term clinical impact of polymer-free sirolimus-eluting stents in unselected patients

OBJECTIVES

The long-term clinical impact of polymer-free sirolimus-eluting stents (PF-SES) in unselected patients undergoing percutaneous coronary intervention (PCI) still remains poorly investigated. We studied the long-term clinical impact of PF-SES in a large cohort of unselected patients receiving PCI therapy at two tertiary care centers in India.

METHODS

A total of 3213 patients received PCI with drug-eluting stents during the period from December 2004 to September 2011. Among these, those receiving PF-SES implantation were retrospectively included in this registry. The primary endpoint in our study was the occurrence of major adverse cardiac events (MACE), defined as the composite of death/myocardial infarction (MI) and target lesion revascularization, whereas the main secondary endpoints were cardiac death/MI and definite/probable stent thrombosis.

RESULTS

A total of 1213 patients (83.8% men, 31.8% diabetics) with 1658 lesions (52.5% B2/C, according to the American College of Cardiology/American Heart Association classification) were studied. After a median follow-up of 1160 days, MACE occurred in 10.0% of patients, whereas the rates of cardiac death/MI and definite/probable ST were found to be 5.4 and 1.9%, respectively. The incidence of MACE was more common in patients aged at least 65 years [hazard ratio (HR)=1.69, 95% confidence interval (CI)=1.13-2.52, P=0.01] and diabetics (HR=1.71, 95% CI=1.18-2.47, P=0.004). The incidence of cardiac death/MI was more common in patients aged at least 65 years (HR=2.21, 95% CI=1.32-3.70, P=0.003). The baseline risk profile did not impact the occurrence of target lesion revascularization.

CONCLUSION

In this large cohort of unselected PCI patients treated in India, PF-SES shows a sustained safety and efficacy at long-term follow-up.

Polymer-free versus permanent polymer drug eluting stents in coronary artery disease: A meta-analysis of 10 RCTs with 6575 patients

Background

Permanent polymer drug eluting stents (PP-DES) may induce inflammation of the vessel wall due to the existence of the polymer, which may delay intimal healing. Polymer-free DES (PF-DES) that eliminate the polymeric carrier may potentially lead to safer DES. However, the safety and efficacy of PF-DES remains controversial.

Methods

Randomized controlled trials comparing PF-DES with PP-DES were searched in online database including MEDLINE, Excerpta Medica Database (EMBASE) and Cochrane Library. Studies reporting late lumen loss (LLL), all-cause death, myocardial infarction (MI), target lesion revascularization (TLR) and late stent thrombosis (LST) were enrolled and quantitatively analyzed.

Results

Ten studies enrolling 6575 patients were included in this meta-analysis. The PF-DES showed a benefit in reducing all-cause death (OR = 0.77, 95% CI: 0.61 to 0.98, P = 0.03) and long-term LLL (weighted mean difference (WMD) −0.16 mm, 95% CI: −0.22 to −0.11 mm, P < 0.001), while no superiority was found in reducing short-term LLL (WMD 0.03 mm, 95% CI: −0.07–0.13 mm, P = 0.57), MI (OR = 1.12, 95% CI: 0.19 to 23.18, P = 0.39), TLR (OR = 1.19, 95% CI: 0.42 to 3.38, P = 0.83) and LST (OR = 0.92, 95% CI: 0.05 to 5.71, P = 0.74).

Conclusion

PF-DES showed benefits in reducing long-term LLL and mortality compared with PP-DES, but no superiority was found in short-term LLL, MI, TLR and LST. These findings provide a sound basis for the wide application of PF-DES in the future.

Matrix metalloproteinase 9 level as an indicator for restenosis following cervical and intracranial angioplasty and stenting

Cervical and intracranial angioplasty and stenting is an effective and safe method of reducing the risk of ischemic stroke, but it may be affected by in-stent restenosis. The present study investigated serum level of matrix metalloproteinase 9 as a predictor of restenosis after 40 patients underwent cervical and/or intracranial angioplasty and stenting. Results showed that restenosis occurred in 30% (3/10) of patients when the serum level of matrix metalloproteinase 9 at 3 days after surgery was 2.5 times higher than preoperative level. No restenosis occurred when the serum level of matrix metalloproteinase 9 at 3 days after surgery was not 2.5 times higher than preoperative level. Restenosis occurred in 12% (2/17) of patients when the serum level of matrix metalloproteinase 9 was higher than preoperative level for more than 30 days after surgery, but only occurred in 4% (1/23) of patients when the serum level of matrix metalloproteinase 9 was higher than preoperative level for less than 30 days after surgery. However, the differences observed were not statistically significant (P > 0.05). Experimental findings indicate that when the serum level of matrix metalloproteinase 9 is 2.5 times higher than preoperative level at 3 days after cervical and intracranial angioplasty and stenting, it may serve as a predictor of in-stent restenosis.

Polymer-Free Drug-Eluting Stents: An Overview of Coating Strategies and Comparison with Polymer-Coated Drug-Eluting Stents

Clinical evaluations have proven the efficacy of drug-elution stents (DES) in reduction of in-stent restenosis rates as compared to drug-free bare metal stents (BMS). Typically, DES are metal stents that are covered with a polymer film loaded with anti-inflammatory or antiproliferative drugs that are released in a sustained manner. However, although favorable effects of the released drugs have been observed, the polymer coating as such has been associated with several adverse clinical effects, such as late stent thrombosis. Elimination of the polymeric carrier of DES may therefore potentially lead to safer DES. Several technologies have been developed to design polymer-free DES, such as the use of microporous stents and inorganic coatings that can be drug loaded. Several drugs, including sirolimus, tacrolimus, paclitaxel, and probucol have been used in the design of carrier-free stents. Due to the function of the polymeric coating to control the release kinetics of a drug, polymer-free stents are expected to have a faster drug elution rate, which may affect the therapeutic efficacy. However, several polymer-free stents have shown similar efficacy and safety as the first-generation DES, although the superiority of polymer-free DES has not been established in clinical trials.

A new polymer-free drug-eluting stent with nanocarriers eluting sirolimus from stent-plus-balloon compared with bare-metal stent and with biolimus A9 eluting stent in porcine coronary arteries

BACKGROUND

Permanent polymers in first generation drug-eluting stent (DES) have been imputed to be a possible cause of persistent inflammation, remodeling, malapposition and late stent thrombosis. We aim to describe the in vivo experimental result of a new polymer-free DES eluting sirolimus from stent-plus-balloon (Focus np stent, Envision Scientific) compared with a bare-metal stent (BMS) (Amazonia CroCo, Minvasys) and with a biolimus A9 eluting stent (Biomatrix, Biosensors).

METHODS

In 10 juvenile pigs, 23 coronary stents were implanted in the coronary arteries (8 Amazonia CroCo, 8 Focus np, and 7 Biomatrix). At 28-day follow-up, optical coherence tomography (OCT) and histology were used to evaluate neointimal hyperplasia and healing response.

RESULTS

According to OCT analysis, Focus np stents had a greater lumen area and less neointimal hyperplasia response than BMS and Biomatrix had. Histomorphometry results showed less neointimal hyperplasia in Focus np than in BMS. Histology showed a higher fibrin deposition in Biomatrix stent compared to Focus np and BMS.

CONCLUSIONS

The new polymer-free DES with sirolimus eluted from stent-plus-balloon demonstrated safety and reduced neointimal proliferation compared with the BMS and Biomatrix stents at 28-day follow-up in this porcine coronary model. This new polymer-free DES is promising and warrants further clinical studies.

Novel potential targets for prevention of arterial restenosis: insights from the pre-clinical research

Restenosis is the pathophysiological process occurring in 10-15% of patients submitted to revascularization procedures of coronary, carotid and peripheral arteries. It can be considered as an excessive healing reaction of the vascular wall subjected to arterial/venous bypass graft interposition, endarterectomy or angioplasty. The advent of bare metal stents, drug-eluting stents and of the more recent drug-eluting balloons, have significantly reduced, but not eliminated, the incidence of restenosis, which remains a clinically relevant problem. Biomedical research in pre-clinical animal models of (re)stenosis, despite its limitations, has contributed enormously to the identification of processes involved in restenosis progression, going well beyond the initial dogma of a primarily proliferative disease. Although the main molecular and cellular mechanisms underlying restenosis have been well described, new signalling molecules and cell types controlling the progress of restenosis are continuously being discovered. In particular, microRNAs and vascular progenitor cells have recently been shown to play a key role in this pathophysiological process. In addition, the advanced highly sensitive high-throughput analyses of molecular alterations at the transcriptome, proteome and metabolome levels occurring in injured vessels in animal models of disease and in human specimens serve as a basis to identify novel potential therapeutic targets for restenosis. Molecular analyses are also contributing to the identification of reliable circulating biomarkers predictive of post-interventional restenosis in patients, which could be potentially helpful in the establishment of an early diagnosis and therapy. The present review summarizes the most recent and promising therapeutic strategies identified in experimental models of (re)stenosis and potentially translatable to patients subjected to revascularization procedures.

Polymer-free sirolimus-eluting versus polymer-based paclitaxel-eluting stents: an individual patient data analysis of randomized trials

INTRODUCTION AND OBJECTIVES

The angiographic and clinical efficacy of polymer-free sirolimus-eluting stents vs polymer-based paclitaxel-eluting stents remain a matter of debate. We sought to investigate angiographic and clinical measures of efficacy of polymer-free sirolimus-eluting stents vs polymer-based paclitaxel-eluting stents.

METHODS

Patient data from the randomized intracoronary stenting and angiographic restenosis-test equivalence between the 2 drug-eluting stents (ISAR-TEST) clinical trial and the LIPSIA Yukon clinical trial (randomized comparison of a polymer-free sirolimus-eluting stent vs a polymer-based paclitaxel-eluting stent in patients with diabetes mellitus) were pooled. The angiographic (primary) endpoint was in-stent late lumen loss at 6 months to 9 months. The clinical (secondary) endpoints were death or myocardial infarction, cardiac death or myocardial infarction, target lesion revascularization, and myocardial infarction.

RESULTS

A total of 686 patients (polymer-free sirolimus-eluting stents, n=345 vs polymer-based paclitaxel-eluting stents, n=341) and 751 lesions (polymer-free sirolimus-eluting stents, n=383 vs polymer-based paclitaxel-eluting stents, n=368) were included in the study. Control angiography (606 lesions, 80.6%) showed comparable in-stent late lumen loss for polymer-free sirolimus-eluting stents vs polymer-based paclitaxel-eluting stents (0.53 [0.59] mm vs 0.46 [0.57] mm; P=.15). Median follow-up was 34.8 months. Polymer-free sirolimus-eluting stents and polymer-based paclitaxel-eluting stents were associated with comparable risk of death or myocardial infarction (relative risk=1.17; 95% confidence interval, 0.49-2.80; P=.71), cardiac death or myocardial infarction (relative risk=1.17; 95% confidence interval, 0.72-1.89; P=.50), target lesion revascularization (relative risk=0.98; 95% confidence interval, 0.65-1.47; P=.93), and myocardial infarction (relative risk=1.79; 95% confidence interval, 0.85-3.76; P=.12).

CONCLUSIONS

In this pooled analysis, polymer-free sirolimus-eluting stents were comparable to polymer-based paclitaxel-eluting stents with respect to both angiographic and clinical efficacy.

Choosing the right coronary stent in the modern era

Research and development in the field of coronary stent design is a fast-evolving and fascinating journey. A device that was once introduced to salvage acute closure associated with balloon angioplasty is now the standard of care for many patients with coronary artery disease. Newer generation stents are the product of remarkable progress in technology and innovation, driven by the need to make the stents easier to deliver and to improve their safety and efficacy. As such, the design of these stents has become quite sophisticated and complex. The number of available stents has increased giving patients and physicians more choices on one hand, but also created confusion in selecting the optimal stent for a given patient. Although a 'one size fits all' approach may not be reasonable, several randomized trials have attested to the efficacy and safety of newer generation durable polymer drug eluting stents. This article discusses the evidence base to support various stent choices in contemporary practice.

Similar five-year outcome with paclitaxel- and sirolimus-eluting coronary stents

OBJECTIVE

Millions of patients were treated with the sirolimus-eluting Cypher™ and the paclitaxel-eluting Taxus™ coronary stents with potential late-occurring increase in event rates. Therefore, the long-term outcome follow-up is of major clinical interest.

DESIGN

In total, 2.098 unselected patients with ST-segment elevation myocardial infarction (STEMI), non-STEMI, stable or unstable angina pectoris were randomized to receive Cypher™ (n = 1.065) or Taxus™ (n = 1.033) stents and were followed for 5 years.

RESULTS

The primary end-point; the composite of cardiac death, myocardial infarction and target vessel revascularization (major adverse cardiac event, MACE), occurred in 467 patients (22.3%); Cypher™ n = 222 (20.8%), Taxus™ n = 245 (23.7%), ns. Definite and probable stent thrombosis occurred in 107 patients (5.1%); Cypher™ n = 51 (4.8%), Taxus™ n = 56 (5.4%), ns. No statistically significant differences were found in the elements of the primary end-point or in other secondary end-points between the two stent groups. After one year, the annual rates of stent thrombosis and MACE remained constant.

CONCLUSIONS

During 5-year follow-up, the Cypher™ and the Taxus™ coronary stents had similar clinical outcome with no signs of increasing rates of adverse events over time.

Current application and bioavailability of drug-eluting stents

INTRODUCTION

Drug-eluting stents (DES) were developed to reduce the restenosis rate of bare metal stents (BMS) and comprises three main components: i) a metallic scaffold; ii) an antiproliferative drug to reduce or abolish the formation of the neointima; and iii) the polymer, which both enables and controls drug elution into the vessel wall. Over the years, growing evidence has been reported on the safety and efficacy for different indications of DES.

AREAS COVERED

Since the introduction of first-generation DES, the technology has been refined, including changes in the alloy, stent design, polymer, drug and drug dose. In 2014, we will usher in a third generation of DES, which will include biodegradable polymers, polymer-free DES and bioabsorbable scaffolds.

EXPERT OPINION

In recent years, considerable progress has been made in DES development. The BMS platform set the groundwork for the development of metal scaffolds with drug-eluting capability to prevent restenosis. Importantly, extensive research has shown long-term safety and efficacy of the newer generation DES. Available data suggest that DES can be safely and effectively used to treat a complex subset of patients and lesions, including patients presenting with acute myocardial infarction, lesions in saphenous vein grafts, chronic total occlusions, multivessel disease, small vessels, long lesions and bifurcations. One of the safety targets is to eliminate stent thrombosis.

Long-term safety of drug-eluting stents

Stent implantation in coronary stenosis has revolutionized the treatment of coronary artery disease. The introduction of antirestenotic drug coatings further improved their efficacy in reducing target vessel revascularizations. With increasing use of drug-eluting stents (DES), stent thrombosis (ST) rose as potentially fatal major complication. Initially, the incidence of ST late after stent implantation seemed to be similar for DES and bare metal stents until several studies proved otherwise in first-generation DES. Since then, the design and components of DES have been changed and new polymers, drugs and different combinations of platelet inhibitors have been introduced to further improve the safety of DES. In this review, the authors focus on the relationship between DES, lesion anatomy, implantation technique and pharmacology to avoid the occurrence of ST. Furthermore, the relationship between dual antiplatelet therapy, bleeding rate and its significant impact on patient outcome is discussed. Finally, some promising future concepts are highlighted.

Five-year clinical follow-up of a randomized comparison of a polymer-free sirolimus-eluting stent versus a polymer-based paclitaxel-eluting stent in patients with diabetes mellitus (LIPSIA Yukon trial)

OBJECTIVES

The long-term performance of polymer-free stent systems in patients with diabetes mellitus has not been investigated extensively. This study reports long-term results of the LIPSIA Yukon trial which compared the polymer-free sirolimus-eluting Yukon Choice stent with the polymer-based paclitaxel-eluting Taxus Liberté stent in this subpopulation. At 9 months, the Yukon Choice stent failed to show non-inferiority in terms of the primary end point late lumen loss, while no significant difference in clinical outcome was detected.

METHODS AND RESULTS

The LIPSIA Yukon trial randomized 240 patients with diabetes mellitus to a polymer-free sirolimus eluting stent (Yukon Choice, Translumina) versus a polymer-based paclitaxel-eluting stent (Taxus Liberté, Boston Scientific). Clinical follow-up was conducted with a standardized telephone follow-up and all events were centrally adjudicated. Follow-up was available for 98.3% of patients after a median of 5.0 years. The incidence of all-cause death (16.9% versus 14.0%, P = 0.67), respectively definite or presumed cardiovascular death (7.6% versus 8.8%, P = 0.94) were similar in the Yukon Choice and the Taxus Liberté group. There were no significant differences in the rates of myocardial infarction (9.3% versus 7.9%, P = 0.88), definite stent thrombosis (0.8% versus 0.9%, P = 1.0), target lesion revascularization (15.3% versus 15.8%, P = 1.0), target vessel revascularization (18.6% versus 23.7%, P = 0.44), non-target vessel revascularization (18.6% versus 26.3%, P = 0.21), and stroke (3.4% versus 4.4%, P = 0.96) between patients assigned to the Yukon Choice and the Taxus Liberté stent.

CONCLUSION

At 5 years of follow-up, clinical outcome was similar between the polymer-free sirolimus-eluting Yukon Choice stent and the polymer-based paclitaxel-eluting Taxus Liberté stent.

Drug eluting balloons for de novo coronary lesions - a systematic review and meta-analysis

BACKGROUND

The role of drug-eluting balloons (DEB) is unclear. Increasing evidence has shown a benefit for the treatment of in-stent restenosis. Its effect on de novo coronary lesions is more controversial. Several smaller randomized trials found conflicting results.

METHODS

This is a systematic review and meta-analysis of randomized controlled trials (RCT) evaluating the effect of local Paclitaxel delivery/drug eluting balloons (DEB) (+/- bare metal stent) compared to current standard therapy (stenting) to treat de novo coronary lesions. Data sources for RCT were identified through a literature search from 2005 through 28 December 2012. The main endpoints of interest were target lesion revascularization (TLR), major adverse cardiac events (MACE), binary in-segment restenosis, stent thrombosis (ST), myocardial infarction (MI), late lumen loss (LLL) and mortality. A random effects model was used to calculate the pooled relative risks (RR) with 95% confidence intervals.

RESULTS

Eight studies (11 subgroups) and a total of 1,706 patients were included in this analysis. Follow-up duration ranged from 6 to 12 months. Overall, DEB showed similar results to the comparator treatment. The relative risk (RR) for MACE was 0.95 (0.64 to 1.39); P = 0.776, for mortality it was 0.79 (0.30 to 2.11), P = 0.644, for stent thrombosis it was 1.45 (0.42 to 5.01), P = 0.560, for MI it was 1.26 (0.49 to 3.21), P = 0.629, for TLR it was 1.09 (0.71 to 1.68); P = 0.700 and for binary in-stent restenosis it was 0.96 (0.48 to 1.93), P = 0.918. Compared to bare metal stents (BMS), DEB showed a lower LLL (- 0.26 mm (-0.51 to 0.01)) and a trend towards a lower MACE risk (RR 0.66 (0.43 to 1.02)).

CONCLUSION

Overall, drug-eluting balloons (+/- bare metal stent) are not superior to current standard therapies (BMS or drug eluting stent (DES)) in treating de novo coronary lesions. However, the performance of DEB seems to lie in between DES and BMS with a trend towards superiority over BMS alone. Therefore, DEB may be considered in patients with contraindications for DES. The heterogeneity between the included studies is a limitation of this meta-analysis; different drug-eluting balloons have been used.

Progress in treatment by percutaneous coronary intervention: the stent of the future

First generation drug-eluting stents have considerably reduced in-stent restenosis and broadened the applications of percutaneous coronary interventions for the treatment of coronary artery disease. The polymer is an integral part of drug-eluting stents in that, it controls the release of an antiproliferative drug. The main safety concern of first generation drug-eluting stents with permanent polymers--stent thrombosis--has been caused by local hypersensitivity, delayed vessel healing, and endothelial dysfunction. This has prompted the development of newer generation drug-eluting stents with biodegradable polymers or even polymer-free drug-eluting stents. Recent clinical trials have shown the safety and efficacy of drug-eluting stents with biodegradable polymer, with proven reductions in very late stent thrombosis as compared to first generation drug-eluting stents. However, the concept of using a permanent metallic prosthesis implies major drawbacks, such as the presence of a foreign material within the native coronary artery that causes vascular inflammation and neoatherosclerosis, and also impedes the restoration of the vasomotor function of the stented segment. Bioresorbable scaffolds have been introduced to overcome these limitations, since they provide temporary scaffolding and then disappear, liberating the treated vessel from its cage. This update article presents the current status of these new technologies and highlights their future perspectives in interventional cardiology.