The 2010s in clinical drug-eluting stent and bioresorbable scaffold research: a Dutch perspective

Atlas Drug-Eluting Coronary Stents Inhibit Neointimal Hyperplasia in Sheep Modeling

Background

Coronary artery disease (CAD) is one of the leading causes of mortality and morbidity worldwide. Many patients with CAD require mechanical revascularization. However, restenosis after minimally invasive interventions is a major problem for these patients. Fortunately, the controlled drug delivery properties of drug-eluting stents seem to be able to overcome this problem. In this study, the pharmacodynamic and pharmacokinetic properties of Atlas Drug-eluting Coronary Stents coated with poly (lactic acid-coglycolic acid) (PLGA) were evaluated.

Materials and Methods

This study included 20 non-atherosclerotic female sheep divided into 4 groups that included 4 study and 1 control animal randomly assigned to each group. Animals in the study groups were stented with Atlas Drug-eluting Coronary Stents, and the pharmacodynamic and pharmacokinetic properties were evaluated.

Results

Sirolimus was shown to have a statistically important effect on the vascular endothelium. With time, the decrease in sirolimus in blood samples was statistically significant. Two animals died after implantation; however no clinically significant side effects were observed in the others.

Conclusions

The results in this study showed a significant reduction in neointimal hyperplasia after experimental implantation of Atlas Drug-eluting Coronary Stents coated with PLGA polymer. Pharmacokinetic studies also showed that the stent did not release a significant amount of sirolimus after 28 days.

Ethnic minorities treated with new-generation drug-eluting coronary stents in two European randomised clinical trials

BACKGROUND

Several ethnic minorities have an increased risk of cardiovascular events, but previous European trials that investigated clinical outcome after coronary stenting did not assess the patients' ethnic background.

AIMS

To compare ethnic minority and Western European trial participants in terms of both cardiovascular risk profile and 1‑year clinical outcome after percutaneous coronary intervention.

METHODS

In the BIO-RESORT and BIONYX randomised trials, which assessed new-generation drug-eluting stents, information on patients' self-reported ethnic background was prospectively collected. Pooled patient-level data of 5803 patients, enrolled in the Netherlands and Belgium, were analysed in this prespecified analysis. The main endpoint was target vessel failure after 1 year.

RESULTS

Patients were classified as belonging to an ethnic minority (n = 293, 5%) or of Western European origin (n = 5510, 95%). Follow-up data were available in 5772 of 5803 (99.5%) patients. Ethnic minority patients were younger, less often female, more often current smokers, more often medically treated for diabetes, and more often had a positive family history of coronary artery disease. The main endpoint target vessel failure did not differ between ethnic minority and Western European patients (3.5% vs 4.9%, hazard ratio 0.71, 95% confidence interval 0.38-1.33; p = 0.28). There was also no difference in mortality, myocardial infarction, and repeat revascularisation rates.

CONCLUSIONS

Despite the unfavourable cardiovascular risk profile of ethnic minority patients, short-term clinical outcome after treatment with contemporary drug-eluting stents was highly similar to that in Western European patients. Further efforts should be made to ensure the enrolment of more ethnic minority patients in future coronary stent trials.

Ten-year mortality after treating obstructive coronary atherosclerosis with contemporary stents in patients with or without concomitant peripheral arterial disease

BACKGROUND AND AIMS

Previous studies in percutaneous coronary intervention (PCI) patients showed a higher 3-year adverse event risk, including all-cause mortality, in those with concomitant peripheral arterial disease (PADs). Ten-year data of mortality and causes of death are scarce. This analysis assessed PCI patients, treated with contemporary drug-eluting stents, the impact of concomitant PADs on very long-term mortality, and causes of death.

METHODS

We assessed PCI all-comers from our center who participated in the TWENTE and DUTCH PEERS trials (clinicaltrials.gov:NCT01066650, NCT01331707), comparing patients with versus without PADs. Life status was checked in the Dutch Personal Records Database; causes of death were obtained from medical records.

RESULTS

Of 2705 study patients, 668 (24.7%) died during follow-up: 88/212 (41.5%) patients with PADs and 580/2493 (23.1%) without PADs. In PADs patients, the 10-year rate of all-cause mortality was about twice as high as in patients without PADs (41.5% vs.23.1%, HR: 2.05, 95%-CI: 1.64-2.57, p<0.001). For both groups, the rates of patients dying from various causes of death were: cardiac (14.1% vs.6.8%), vascular (2.8% vs. 1.1%), non-cardiovascular (17.4% vs. 9.8%), and unclear causes (7.1% vs. 5.3%), without a statistically significant between-group difference. When multivariate analysis was adjusted for between-group differences in cardiovascular risk profile, PADs remained predictor of all-cause mortality (adjusted HR: 1.38, 95%-CI: 1.08-1.75, p=0.01).

CONCLUSIONS

The 10-year all-cause mortality rate in PCI patients with concomitant PADs was almost twice as high as in those without PADs. Age and other traditional cardiovascular risk factors were higher in patients with PADs, but after correction for these confounders PADs still accounted for almost 40% increase in mortality.

Finite element analysis of the mechanical performance of a zinc alloy stent with the tenon-and-mortise structure

BACKGROUND

Inadequate scaffolding performance hinders the clinical application of the biodegradable zinc alloy stents.

OBJECTIVE

In this study we propose a novel stent with the tenon-and-mortise structure to improve its scaffolding performance.

METHODS

3D models of stents were established in Pro/E. Based on the biodegradable zinc alloy material and two numerical simulation experiments were performed in ABAQUS. Firstly, the novel stent could be compressed to a small-closed ring by a crimp shell and can form a tenon-and-mortise structure after expanded by a balloon. Finally, 0.35 MPa was applied to the crimp shell to test the scaffolding performance of the novel stent and meanwhile compare it with an ordinary stent.

RESULTS

Results showed that the novel stent decreased the recoiling ratio by 70.7% compared with the ordinary stent, indicating the novel structure improved the scaffolding performance of the biodegradable zinc alloy stent.

CONCLUSION

This study proposes a novel design that is expected to improve the scaffolding performance of biodegradable stents.

Cardiovascular Stents: A Review of Past, Current, and Emerging Devices

One of the leading causes of morbidity and mortality worldwide is coronary artery disease, a condition characterized by the narrowing of the artery due to plaque deposits. The standard of care for treating this disease is the introduction of a stent at the lesion site. This life-saving tubular device ensures vessel support, keeping the blood-flow path open so that the cardiac muscle receives its vital nutrients and oxygen supply. Several generations of stents have been iteratively developed towards improving patient outcomes and diminishing adverse side effects following the implanting procedure. Moving from bare-metal stents to drug-eluting stents, and recently reaching bioresorbable stents, this research field is under continuous development. To keep up with how stent technology has advanced in the past few decades, this paper reviews the evolution of these devices, focusing on how they can be further optimized towards creating an ideal vascular scaffold.