Comparison of Efficacy and Safety between First and Second Generation Drug-eluting Stents in Patients with Stable Coronary Artery Disease: A Single-center Retrospective Study

Endothelial Cell Behavior and Nitric Oxide Production on a-C:H:SiOx-Coated Ti-6Al-4V Substrate

This paper focuses on the surface modification of the Ti-6Al-4V alloy substrate via a-C:H:SiOx coating deposition. Research results concern the a-C:H:SiOx coating structure, investigated using transmission electron microscopy and in vitro endothelization to study the coating. Based on the analysis of the atomic radial distribution function, a model is proposed for the atomic short-range order structure of the a-C:H:SiOx coating, and chemical bonds (C-O, C-C, Si-C, Si-O, and Si-Si) are identified. It is shown that the a-C:H:SiOx coating does not possess prolonged cytotoxicity in relation to EA.hy926 endothelial cells. In vitro investigations showed that the adhesion, cell number, and nitric oxide production by EA.hy926 endothelial cells on the a-C:H:SiOx-coated Ti-6Al-4V substrate are significantly lower than those on the uncoated surface. The findings suggest that the a-C:H:SiOx coating can reduce the risk of endothelial cell hyperproliferation on implants and medical devices, including mechanical prosthetic heart valves, endovascular stents, and mechanical circulatory support devices.

Morphofunctional reaction of leukocytes and platelets in in vitro contact with a-C:H:SiOx -coated Ti-6Al-4V substrate

The article deals with the plasma-assisted chemical vapor deposition of 0.3-1.4 μm thick a-C:H:SiO_x films in a mixture of argon and polyphenylmethylsiloxane vapor onto the Ti-6Al-4V alloy substrate, which is often used as an implant material. The a-C:H:SiO_x film structure is studied by the Fourier-transform infrared and Raman spectroscopies. The pull-off adhesion test assesses the adhesive strength of a-C:H:SiO_x films, and the ball-on-disk method is employed to measure their wear rate and friction coefficient. According to these studies, a-C:H:SiO_x films are highly adhesive to the Ti-6Al-4V substrate, have low (0.056) friction coefficient and wear rate (9.8 × 10^-8  mm³  N^-1  m^-1 ) in phosphate-buffered saline at 40°C. In vitro studies show neither thrombogenicity nor cytotoxicity of the a-C:H:SiO_x film for the human blood mononuclear cells (hBMNCs). The in vitro contact between the hBMNC culture and a-C:H:SiO_x films 0.8-1.4 μm thick deposited onto Ti-6Al-4V substrates reduces a 24-hour secretion of pro-inflammatory cytokines and chemokines IL-8, IL-17, TNFα, RANTES, and MCP-1. This reduction is more significant when the film thickness is 1.4 μm and implies its potential anti-inflammatory effect and possible application in cardiovascular surgery. The dependence is suggested for the concentration of anti-inflammatory cytokines and chemokines and the a-C:H:SiO_x film thickness, which correlates with the surface wettability and electrostatic potential. The article discusses the possible applications of the anti-inflammatory effect and low thrombogenicity of a-C:H:SiO_x films in cardiovascular surgery.

Comparison of Efficacy and Safety between First- and Second-Generation Drug-Eluting Stents in Patients with Acute Coronary Syndrome

Background:

It remains undetermined whether second-generation drug-eluting stents (G2-DESs) outperform first-generation DESs (G1-DESs) in patients with acute coronary syndrome (ACS). We aimed to compare the efficacy and safety of G1-DES and G2-DES in ACS patients in a high-volume cardiovascular center.

Methods:

In 2013, 10,724 consecutive patients underwent percutaneous coronary intervention in our institution. We included 4037 patients with ACS who underwent exclusively G1-DES or G2-DES implantation (n = 364 and n = 3673, respectively). We used propensity score matching to minimize the imbalance between the G1-DES and G2-DES groups and followed patients for 2 years. The efficacy endpoints were major adverse cardiac events (MACEs) and its components including target vessel-related myocardial infarction (TV-MI), target vessel revascularization/target lesion revascularization (TVR/TLR), and cardiac death. The safety endpoint was stent thrombosis. Continuous variables were compared by Mann-Whitney U-test, and categorical variables were compared using Pearson's Chi-square or Fisher's exact test. Kaplan-Meier curves were constructed to compare the event-free survival rates, and multivariate Cox proportional hazards regression analysis was used to assess whether stent type was an independent risk factor for the efficacy and safety endpoints.

Results:

At the 2-year follow-up, the results for MACE and it components, as well as stent thrombosis, were similar for G1-DES and G2-DES (MACE, 5.2% vs. 4.3%, χ² = 0.514, P = 0.474; TV-MI, 0.8% vs. 0.4%, P = 0.407; TVR, 4.9% vs. 3.7%, χ² = 0.939, P = 0.333; TLR, 3.8% vs. 2.5%, χ² = 1.610, P = 0.205; cardiac death, 0.3% vs. 0.5%, P = 0.670; and stent thrombosis, 0.5% vs. 0.4%, P > 0.999). Kaplan-Meier analysis indicated similar event-free survival rates between G1-DES and G2-DES after propensity score matching (all: log-rank P > 0.05). Multivariate analysis demonstrated that stent type was not an independent risk factor for the efficacy and safety endpoints (MACE, hazard ratio [HR] = 0.805, 95% confidence interval [CI]: 0.455–1.424, P = 0.456; TV-MI, HR = 0.500, 95% CI: 0.101–2.475, P = 0.395; TVR, HR = 0.732, 95% CI: 0.403–1.330, P = 0.306; TLR, HR = 0.629, 95% CI: 0.313–1.264, P = 0.193; cardiac death, HR = 1.991, 95% CI: 0.223–17.814, P = 0.538; and stent thrombosis, HR = 0.746, 95% CI: 0.125–4.467, P = 0.749).

Conclusion:

G1-DES and G2-DES have similar efficacy and safety profiles in ACS patients at the 2-year follow-up.

Drug-Eluting Balloon versus New-Generation Drug-Eluting Stent for the Treatment of In-Stent Restenosis: An Updated Systematic Review and Meta-Analysis

BACKGROUND

Currently, drug-eluting balloon (DEB) appears to be an attractive alternative option for the treatment of in-stent restenosis (ISR). Nevertheless, the clinical outcomes of DEB have seldom been compared to those of new-generation drug-eluting stent (DES). Thus, this meta-analysis aimed to evaluate the safety and efficacy of DEB compared to those of new-generation DES in the treatment of ISR.

METHODS

A comprehensive search of electronic databases including PubMed, EMBASE, and Cochrane Library up to November 2, 2017 was performed to identify pertinent articles comparing DEB to new-generation DES for the treatment of ISR. In addition, conference proceedings for the scientific sessions of the American College of Cardiology, American Heart Association, European Society of Cardiology, Transcatheter Cardiovascular Therapeutics, and EuroPCR were also searched. The primary endpoint was target lesion revascularization (TLR) at the longest follow-up. Dichotomous variables were presented as risk ratios (RR s) with 95% confidence intervals (CI s), while the overall RR s were estimated using the Mantel-Haenszel random-effects model.

RESULTS

Five randomized controlled trials (RCTs) and eight observational studies involving 2743 patients were included in the present meta-analysis. Overall, DEB was comparable to new-generation DES in terms of TLR (RR = 1.24, 95% CI: 0.89-1.72, P = 0.21), cardiac death (RR = 1.55, 95% CI: 0.89-2.71, P = 0.12), major adverse cardiovascular event (RR = 1.21, 95% CI: 0.98-1.48, P = 0.07), myocardial infarction (RR = 1.12, 95% CI: 0.72-1.76, P = 0.62), and stent thrombosis (RR = 0.95, 95% CI: 0.38-2.42, P = 0.92). However, DEB was associated with higher risk of all-cause mortality than new-generation DES (RR = 1.65, 95% CI: 1.09-2.50, P = 0.02). This was especially true in the real-world observational studies (RR = 1.79, 95% CI: 1.12-2.88, P = 0.02). In RCTs, however, no significant difference was found between the two treatment strategies in the risk of all-cause mortality.

CONCLUSIONS

The current meta-analysis showed that DEB and new-generation DES had comparable safety and efficacy for the treatment of ISR in RCTs. However, treatment with DEB was associated with higher risk of all-cause mortality in the real-world nonrandomized studies.