Late Stent Thrombosis: The Last Remaining Obstacle in Coronary Interventional Therapy

Phospholipid-based multifunctional coating via layer-by-layer self-assembly for biomedical applications

As an important class of biomaterials，bionics inspired materials has been widely used in creating extracorporeal and implantable medical devices. However, specific service environment is often faced with multiple requirements rather than single function. Herein, we designed a phospholipid-based multifunctional coating with phospholipids-based polymers, type I collagen (Col-I) and Arg-Glu-Asp-Val (REDV) peptide, via layer-by-layer assembly. The successful synthesis of the polymers and the coating is proved by a series of characterization methods including Fourier transforming infrared spectra (FTIR), proton nuclear magnetic resonance (¹H NMR), ultraviolet-visible spectra (UV) and X-ray photoelectron spectroscopy (XPS), while the assembly process and quality change of the coating were monitored via quartz crystal microbalance (QCM). Besides, hydrophilicity and roughness of this coating was analyzed via water contact angle (WCA) and atomic force microscope (AFM), respectively. Finally, results from platelet adhesion, activation assay, smooth muscle cells (SMCs) and endothelial cells (ECs) cultures indicated that the multifunctional coating could strongly inhibit platelet adhesion and SMCs proliferation, hence provide practical application of the coating with good biocompatibility, especially the anticoagulant property and cell compatibility. It is expected that this coating may be used in blood-contacting fields such as cardiovascular stent or other devices in the future.

Protective Function of Ahnak1 in Vascular Healing after Wire Injury

AIM

Vascular remodeling following injury substantially accounts for restenosis and adverse clinical outcomes. In this study, we investigated the role of the giant scaffold protein Ahnak1 in vascular healing after endothelial denudation of the murine femoral artery.

METHODS

The spatiotemporal expression pattern of Ahnak1 and Ahnak2 was examined using specific antibodies and real-time quantitative PCR. Following wire-mediated endothelial injury of Ahnak1-deficient mice and wild-type (WT) littermates, the processes of vascular healing were analyzed.

RESULTS

Ahnak1 and Ahnak2 showed a mutually exclusive vascular expression pattern, with Ahnak1 being expressed in the endothelium and Ahnak2 in the medial cells in naïve WT arteries. After injury, a marked increase of Ahnak1- and Ahnak2-positive cells at the lesion site became evident. Both proteins showed a strong upregulation in neointimal cells 14 days after injury. Ahnak1-deficient mice showed delayed vascular healing and dramatically impaired re-endothelialization that resulted in prolonged adverse vascular remodeling, when compared to the WT littermates.

CONCLUSION

The large scaffold and adaptor proteins Ahnak1 and Ahnak2 exhibit differential expression patterns and functions in naïve and injured arteries. Ahnak1 plays a nonredundant protective role in vascular healing.

Long-term Outcomes of Primary Percutaneous Coronary Intervention with Second-generation Drug-eluting Stents in ST-elevation Myocardial Infarction Patients Caused by Very Late Stent Thrombosis

Background:

The ST-segment elevation myocardial infarction (STEMI) patients due to stent thrombosis (ST) remain a therapeutic challenge for a clinician. Till date, very few researches have been conducted regarding the safety and effectiveness of primary percutaneous coronary intervention (PCI) with second-generation drug-eluting stents (DES) for STEMI caused by very late ST (VLST). This retrospective study evaluated the safety, efficacy, and outcomes of primary PCI with second-generation DES for STEMI due to VLST compared with primary PCI for STEMI due to de novo lesion.

Methods:

Between January 2007 and December 2013, STEMI patients with primary PCI in Fuwai Hospital had only second-generation DES implanted for de novo lesion (558 patients) and VLST (50 patients) were included in this retrospective study. The primary end points included cardiac death and reinfarction. The secondary end points included cardiac death, reinfarction, and target lesion revascularization. Continuous variables were expressed as mean (standard deviation) or median (interquartile range) and compared by Student's t-test or Mann-Whitney U-test as appropriate. Categorical variables were expressed as counts and percentages, and comparison of these variables was performed with Chi-square or Fisher's exact test. A two-tailed value of P < 0.05 was considered statistically significant for all comparisons. Statistical analyses were performed by SAS software (version 9.4, SAS Institute Inc., Cary, USA) for Windows.

Results:

In-hospital primary end point and the secondary end point were no significant differences between two groups (P = 1.000 and P = 1.000, respectively). No significant differences between two groups were observed according to the long-term primary end point and the secondary end point. Kaplan-Meier survival curves showed no significant difference between the two groups in the primary end point and the secondary end point at 2 years (P = 0.340 and P = 0.243, respectively). According to Cox analysis, female, intra-aortic balloon pump support, and postprocedural thrombolysis in myocardial infarction flow 3 were found to be independent predictors for long-term follow-up.

Conclusion:

Primary PCI with second-generation DES is a reasonable choice for STEMI patients caused by VLST.

A nontoxic additive to introduce x-ray contrast into poly(lactic acid). Implications for transient medical implants such as bioresorbable coronary vascular scaffolds

Bioresorbable coronary vascular scaffolds are about to revolutionize the landscape of interventional cardiology. These scaffolds, consisting of a poly(L-lactic acid) interior and a poly(D,L-lactic acid) surface coating, offer a genuine alternative for metallic coronary stents. Perhaps the only remaining drawback is that monitoring during implantation is limited to two X-ray contrast points. Here, a new approach to make the biodegradable scaffolds entirely radiopaque is explored. A new contrast agent is designed and synthesized. This compound is miscible with poly(D,L-lactic acid) matrix, and nontoxic to multiple cell types. Blends of poly(D,L-lactic acid) and the contrast agent are found to be hemocompatible, noncytotoxic, and radiopaque. The data show that it is possible to manufacture fully radiopaque bioresorbable coronary vascular scaffolds. Whole-stent X-ray visibility helps interventionalists ensure that the scaffold deploys completely. This important advantage may translate into improved safety, accuracy, and clinical performance of cardiac stents.

Real-world safety and effectiveness outcomes of a zotarolimus-eluting stent: final 3-year report of the RESOLUTE International study

Objectives

We evaluated the safety and effectiveness of the Resolute™ zotarolimus-eluting stent (R-ZES) in real-world clinical practice through 3 years.

Background

A randomized comparison of the R-ZES and the XIENCE V™ everolimus-eluting stent showed no difference in any outcomes through 3-year follow-up in high-volume academic centers. RESOLUTE International is a confirmatory trial designed to evaluate the R-ZES in real-world clinical practice.

Methods

RESOLUTE International is a single arm, observational trial that enrolled 2,349 patients from 88 centers with only a few inclusion and exclusion criteria. The primary end-point was the composite of cardiac death and target vessel myocardial infarction (TV-MI) at 1 year. Secondary end-points include target lesion failure (TLF), target vessel revascularization (TVR), and their components, and stent thrombosis (ST).

Results

At 3 years 97.2% of patients completed clinical follow-up. The mean age was 63.4 ± 11.2 years, 77.8% were male, and 30.4% had diabetes. The average number of stents per patient was 1.6 ± 1.0; and mean stent length was 30.9 ± 20.5 mm. Dual antiplatelet therapy was used in 91.1% of patients at 1 year, 43.0% at 2 years, and 34.6% at 3 years. Cardiac death and TV-MI occurred in 161 patients (7.0%). There were 6 (0.3%) very late ST events for a total ST rate of 1.1% through 3 years. The rates of clinically driven target lesion revascularization (TLR), TVR, and TLF were 5.7%, 7.4%, and 11.4%, respectively.

Conclusions

The safety and effectiveness of the R-ZES through 3 years in this real-world all-comer study was consistent with previously reported all-comer trials. (J Interven Cardiol 2013;26:515-523)