Clinical performance of biodegradable versus permanent polymer drug-eluting stents: A meta-analysis of randomized clinical trials at long-term follow-up

Outcome of a polymer-free drug-coated coronary stent in bifurcation lesions-Pilot registry with serial OCT imaging

BACKGROUND

Polymer-free and carrier-free drug-coated stents (DCS) represent a novel therapeutic option for the treatment of coronary artery disease. The objective of this pilot registry is to evaluate the safety and efficacy of DCS implantation in bifurcation lesions.

METHODS

Overall, 23 consecutive patients with 24 lesions received a Biolimus A9-coated DCS for coronary bifurcation lesions. Patients were examined with quantitative coronary angiography (QCA) and optical coherence tomography (OCT) at 3-6 months of follow-up.

RESULTS

A total of 23 patients with 24 bifurcation lesions were included in this study. Nine (33.3%) lesions of eight patients revealed angiographical target lesion failure due to in-stent restenosis (ISR). In total, 19 patients with 20 bifurcation lesions were suitable for OCT analysis. A total of 2936 struts were analyzed and 14 struts (0.47%) were classified as malapposed. The mean luminal area (mm2) was not different in lesions with ISR vs. lesions with no ISR (5.07 ± 2.0 vs. 5.73 ± 1.34, p = 0.39) at follow-up. Lesions with ISR showed higher mean neointimal burden (27.11 ± 10.59 vs. 13.93 ± 9.16%, respectively; p = 0.009). All of the patients who presented with significant ISR required percutaneous re-intervention.

CONCLUSIONS

We observed a high rate of DCS ISR in bifurcation lesions, possibly related to increased inflammation and neoatherosclerosis. The small size of the study warrants careful interpretation of our results. Larger trials are necessary to expand knowledge of these findings.

Biodegradable polymer drug-eluting stents versus first-generation durable polymer drug-eluting stents: A systematic review and meta-analysis of 12 randomized controlled trials

BACKGROUND

Even if drug-eluting stents (DES) showed beneficial effects in patients with coronary artery diseases (CADs), limitations have been observed with the first-generation durable polymer DES (DP-DES). Recently, biodegradable polymer DES (BP-DES) have been approved to be used as an alternative to DP-DES, with potential benefits. We aimed to systematically compare BP-DES with the first-generation DP-DES using a large number of randomized patients.

METHODS

Electronic databases were searched for randomized controlled trials (RCTs) comparing BP-DES with first-generation DP-DES. The main endpoints were the long-term (≥2 years) adverse clinical outcomes that were reported with these 2 types of DES. We calculated odds ratios (ORs) with 95% confidence intervals (CIs) and the analysis was carried out by RevMan 5.3 software.

RESULTS

Twelve trials with a total number of 13,480 patients (7730 and 5750 patients were treated by BP-DES and first-generation DP-DES, respectively) were included. During a long-term follow-up period of ≥2 years, mortality, myocardial infarction (MI), target lesion revascularization (TLR), and major adverse cardiac events (MACEs) were not significantly different between these 2 groups with OR: 0.84, 95% CI: 0.66-1.07; P = .16, I = 0%, OR: 1.01, 95% CI: 0.45-2.27; P = .98, I = 0%, OR: 0.91, 95% CI: 0.75-1.11; P = .37, I = 0% and OR: 0.86, 95% CI: 0.44-1.67; P = .65, I = 0%, respectively. Long-term total stent thrombosis (ST), definite ST, and probable ST were also not significantly different between BP-DES and the first-generation DP-DES with OR: 0.77, 95% CI: 0.50-1.18; P = .22, I = 0%, OR: 0.71, 95% CI: 0.43-1.18; P = .19, I = 0% and OR: 1.31, 95% CI: 0.56-3.08; P = .53, I = 6%, respectively.

CONCLUSION

Long-term mortality, MI, TLR, MACEs, and ST were not significantly different between BP-DES and the first-generation DP-DES. However, the follow-up period was restricted to only 3 years in this analysis.

Nanomaterial coatings applied on stent surfaces

The advent of percutaneous coronary intervention and intravascular stents has revolutionized the field of interventional cardiology. Nonetheless, in-stent restenosis, inflammation and late-stent thrombosis are the major obstacles with currently available stents. In order to enhance the hemocompatibility of stents, advances in the field of nanotechnology allow novel designs of nanoparticles and biomaterials toward localized drug/gene carriers or stent scaffolds. The current review focuses on promising polymers used in the fabrication of newer generations of stents with a short synopsis on atherosclerosis and current commercialized stents, nanotechnology's impact on stent development and recent advancements in stent biomaterials is discussed in context.