Real Polymer-Free Sirolimus- and Probucol-Eluting Versus Biodegradable Polymer Sirolimus-Eluting Stents for Obstructive Coronary Artery Disease: DKPLUS-Wave 1, a Multicenter, Randomized, Prospective Trial

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.

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.

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.

Evaluation of the suitability of a fluidized bed process for the coating of drug-eluting stents

Drug-eluting stents are often coated using single-stent coating techniques. In pharmaceutical industry, single-tablet coating is unthinkable. Instead large batches of tablets are coated in fluidized bed apparatuses or pan coaters. Therefore, it was the aim of this work to evaluate whether stents can be coated using a fluidized bed process. For this purpose stents were coated with the model fluorescent drug triamterene embedded in ammonium methacrylate copolymer. Different stent lengths as well as different coating yields were assessed and also a drug-free topcoat was evaluated. The coated stents were analysed regarded coating layer mass, drug content, surface structure, coating thickness and drug release. Furthermore, coating yield and stent defect rate were examined. Except for one stent configuration good results were obtained without optimization of process parameters which indicates the suitability of the method to coat large amounts of stents simultaneously in principle. Drug release was tuneable over a wide range of time spans and a wide range of drug loadings was produced. Further work will be necessary to transform the results of this study from a model stent to a clinically relevant product.

Biodegradable-Polymer Versus Polymer-Free Drug-Eluting Stents for the Treatment of Coronary Artery Disease

BACKGROUND/PURPOSE

Biodegradable-polymer (BP) and polymer-free (PF) drug eluting stents (DES) were developed to reduce the risk of delayed arterial healing observed with durable-polymer (DP) platforms. Although trials demonstrate BP-DES and PF-DES are non-inferior to DP-DES, there is limited data directly comparing these technologies. We performed a meta-analysis to assess the efficacy and safety of BP-DES versus PF-DES for the treatment of coronary artery disease.

METHODS/MATERIALS

Electronic searches were performed identifying randomized trials comparing BP-DES with PF-DES. Co-primary efficacy endpoints were target vessel revascularization (TVR), target lesion revascularization (TLR) and angiographic in-stent late lumen loss (LLL). Co-secondary safety endpoints were all-cause death, myocardial infarction (MI) and stent thrombosis (ST).

RESULTS

Of 208 studies, 5 met inclusion criteria including 1975 patients. At mean follow-up (14 ± 5 months), BP-DES were associated with significantly reduced rates of TVR (OR 0.58, 95%CI 0.37-0.92, p = 0.02), TLR (4.7% vs 9.5%) (OR 0.48, 95%CI 0.31-0.75, p = 0.001) and in-stent LLL (pooled mean difference -0.20 mm, 95%CI -0.24 to -0.16, p < 0.001). There was no difference in safety, including all-cause death (OR 1.24, 95%CI 0.68-2.28, p = 0.48), MI (OR 0.92, 95%CI 0.54-1.56, p = 0.75) or ST (OR 1.58, 95%CI 0.67-3.73, p = 0.30).

CONCLUSIONS

These data suggests that BP-DES are more efficacious when compared with PF-DES for the treatment of CAD.

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.

Current State of Bioabsorbable Polymer-Coated Drug-Eluting Stents

Drug-eluting stents (DES) have been shown to significantly reduce clinical and angiographic restenosis compared to bare metal stents (BMS). The polymer coatings on DES elute antiproliferative drugs to inhibit intimal proliferation and prevent restenosis after stent implantation. Permanent polymers which do not degrade in vivo may increase the likelihood of stent-related delayed arterial healing or polymer hypersensitivity. In turn, these limitations may contribute to an increased risk of late clinical events. Intuitively, a polymer which degrades after completion of drug release, leaving an inert metal scaffold in place, may improve arterial healing by removing a chronic source of inflammation, neoatherosclerosis, and/or late thrombosis. In this way, a biodegradable polymer may reduce late ischemic events. Additionally, improved healing after stent implantation could reduce the requirement for long-term dual antiplatelet therapy and the associated risk of bleeding and cost. This review will focus on bioabsorbable polymer-coated DES currently being evaluated in clinical trials.