First clinical evidence characterizing safety and efficacy of the new CoCr Biolimus-A9 eluting stent: The Biomatrix Alpha™ registry

Investigation of optical and biocompatible properties of polyethylene glycol-aspirin loaded commercial pure titanium for cardiovascular device applications

This research investigates the optical and biocompatible properties of alkali-treated cpTi immersed in aspirin and different molecular weights of polyethylene (PEG). Instrumental characterizations were performed using scanning electron microscopy (SEM), Raman spectroscopy, and ultraviolet–visible spectroscopy. Additionally, drug release, antithrombotic, and cell adhesion studies were conducted in in-vitro conditions. The SEM micrographs showed that heat treatment of NaOH modified cpTi substrates increased the average surface pore size by 217%. Raman spectra’s active modes confirmed the presence of titanate groups which intensified the semiconductive nature of alkali-treated cpTi substrates. Further, the semiconductive nature was confirmed through the shift of the energy bandgap from 2.69 to 2.9 eV. The continuous redshift of the absorbance edge with an increase in the molecular weight of PEG indicates improved optical property. Following the Rigter–Peppas dynamic model, the drug release kinetics showed a non-Fickian dispersion (n < 1) and super case II transport (n = 2.21) for PEG-coated cpTi substrates. The alkali-treated cpTi-aspirin-PEG surface exhibits suitable antithrombotic property and interstitial cell adhesion with PEG coating. The modified surface on cpTi demonstrated a promising technique to improve the optical, antithrombotic, and biocompatibility performances, which are the prime requirement for the blood-interacted cardiovascular devices such as stents.

Evolutionary perspective of drug eluting stents: from thick polymer to polymer free approach

Background

Introduction of Bare Metal Stents (BMS) was itself a revolutionary step in the history of the medical industry; however, Drug Eluting Stents (DES) maintained its superiority over BMS in every aspect from restenosis rate to late lumen loss. The reason behind the magnanimous position of the DES in the stent market is the degree of improvement with which it evolves. New and better stents come into the market every year, surpassing their predecessors by many folds.

Literature review

This review paper discusses the journey of DES with supporting clinical trials in detail. In the first generation, there were stainless-steel stents with thicker coatings. Although they had superior results compared to BMS, there was still room for improvement. Afterward came the second-generation stents, which had superior metal platforms with thinner struts and thin coatings. The drugs were also changed from Paclitaxel and Sirolimus to Zotrolimus and Everolimus. These stents performed best; however, there was an issue of permanent coating, which remained intact over the stent surface after complete drug elution and started to cause issues in longer-term studies. Hence, an improved version of DES was introduced to these permanent coatings called the third generation of drug eluting stents, which initially utilized biodegradable polymer and ultimately moved towards polymer free drug coatings. This generation has introduced a unique amalgam of technologies to achieve its polymer free coatings; however, researchers have numerous prospects of growth in this field. This review paper highlights the major coups of stent technology evolution from BMS to DES, from thick polymeric coatings to thin coatings and from durable polymers to polymer free DES.

Conclusion

In conclusion, though the medical industry promptly accepted BMS as the best treatment option for cardiovascular diseases; however, DES has provided even better results than BMS. In DES, the first and second generation has ruled the technology for many years and are still on the shelves. Still, the issues aroused due to durable polymer shifted the attention towards biodegradable drug eluting stents, the third generation growing rapidly. But the scientific community has not restricted themselves and is investigating bioresorbable stents that completely eliminate the polymer intervention in drug eluting stent technology.

Bio-Performance of Hydrothermally and Plasma-Treated Titanium: The New Generation of Vascular Stents

The research presented herein follows an urgent global need for the development of novel surface engineering techniques that would allow the fabrication of next-generation cardiovascular stents, which would drastically reduce cardiovascular diseases (CVD). The combination of hydrothermal treatment (HT) and treatment with highly reactive oxygen plasma (P) allowed for the formation of an oxygen-rich nanostructured surface. The morphology, surface roughness, chemical composition and wettability of the newly prepared oxide layer on the Ti substrate were characterized by scanning electron microscopy (SEM) with energy-dispersive X-ray analysis (EDX), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and water contact angle (WCA) analysis. The alteration of surface characteristics influenced the material’s bio-performance; platelet aggregation and activation was reduced on surfaces treated by hydrothermal treatment, as well as after plasma treatment. Moreover, it was shown that surfaces treated by both treatment procedures (HT and P) promoted the adhesion and proliferation of vascular endothelial cells, while at the same time inhibiting the adhesion and proliferation of vascular smooth muscle cells. The combination of both techniques presents a novel approach for the fabrication of vascular implants, with superior characteristics.

Shortened dual antiplatelet therapy in contemporary percutaneous coronary intervention era

Percutaneous coronary intervention with stenting is followed by a duration of dual antiplatelet therapy (DAPT) to reduce stent thrombosis and avoid target lesion failure. The period of DAPT recommended in international guidelines following drug-eluting stent implantation is 12 mo for most patients with acute coronary syndrome, and 6 mo for patients with chronic coronary syndrome or high bleeding risk. The new generation of drug-eluting stents have metallic platforms with thinner struts, associated with significantly less stent thrombosis. Shortened DAPT has been investigated with these stents, with evidence from randomised clinical trials for some individual stents showing non-inferior safety and efficacy outcomes. This has to be balanced by the effect of DAPT on secondary prevention of systemic cardiovascular disease especially in high-risk populations. This review will outline the current evidence for individual stents with regards to DAPT duration for both acute coronary syndrome and chronic coronary syndrome and discuss further directions for research and personalised medicine in this contemporary percutaneous coronary intervention era.

Thin Strut CoCr Biodegradable Polymer Biolimus A9-Eluting Stents versus Thicker Strut Stainless Steel Biodegradable Polymer Biolimus A9-Eluting Stents: Two-Year Clinical Outcomes

Background

While thinner struts are associated with improved clinical outcomes in bare-metal stents (BMS), reducing strut thickness may affect drug delivery from drug-eluting stents (DES) and there are limited data comparing otherwise similar thin and thick strut DES. We assessed 2-year outcomes of patients treated with a thin strut (84–88um) cobalt-chromium, biodegradable polymer, Biolimus A9-eluting stent (CoCr-BP-BES) and compared these to patients treated with a stainless steel, biodegradable polymer, Biolimus A9-eluting stent (SS-BP-BES).

Methods

In total, 1257 patients were studied: 400 patients from 12 centres receiving ≥1 CoCr-BP-BES in the prospective Biomatrix Alpha registry underwent prespecified comparison with 857 patients who received ≥1 Biomatrix Flex SS-BP-BES in the LEADERS study (historical control). The primary outcome was major adverse cardiac events (MACE)—cardiac death, myocardial infarction (MI), or clinically driven target vessel revascularization (cd-TVR). Propensity analysis was used to adjust for differences in baseline variables and a landmark analysis at day-3 to account for differences in periprocedural MI definitions.

Results

MACE at 2 years occurred in 6.65% CoCr-BP-BES versus 13.23% SS-BP-BES groups (unadjusted HR 0.48 [0.31–0.73]; P=0.0005). Following propensity analysis, 2-year adjusted MACE rates were 7.4% versus 13.3% (HR 0.53 [0.35–0.79]; P=0.004). Definite or probable stent thrombosis, adjudicated using identical criteria in both studies, occurred less frequently with CoCr-BP-BES (1.12% vs. 3.22%; adjusted HR 0.32 [0.11–0.9]; P=0.034). In day-3 landmark analysis, the difference in 2-year MACE was no longer significant but there was a lower patient-orientated composite endpoint (11.7% vs. 18.4%; HR 0.6 [0.43–0.83]; P=0.006) and a trend to lower target vessel failure (5.8% vs. 9.1%; HR 0.63 [0.4–1.00]; P=0.078).

Conclusion

At 2-year follow-up, propensity-adjusted analysis showed the thin strut (84–88um) Biomatrix Alpha CoCr-BP-BES was associated with improved clinical outcomes compared with the thicker strut (114–120um) Biomatrix Flex SS-BP-BES.

Advances in Clinical Cardiology 2019: A Summary of Key Clinical Trials

INTRODUCTION

A large number of important clinical trials in cardiology were published or presented at major international conferences during 2019. This paper aims to offer a concise overview of these significant advances and to put them into clinical context.

METHODS

Trials presented at the major international cardiology meetings during 2019 were reviewed including The American College of Cardiology (ACC), Euro PCR, The European Society of Cardiology (ESC), Transcatheter Cardiovascular Therapeutics (TCT), and the American Heart Association (AHA). In addition to this a literature search identified several other publications eligible for inclusion based on their relevance to clinical cardiology, their potential impact on clinical practice and on future guidelines.

RESULTS

A total of 70 trials met the inclusion criteria. New interventional and structural data include trials examining use of drug-coated balloons in patients with acute myocardial infarction (MI), interventions following shockable cardiac arrest, mechanical circulatory support in cardiogenic shock complicating MI, intervention in stable coronary artery disease, surgical or percutaneous revascularisation strategies in left main coronary artery disease, revascularisation strategy in ST elevation MI, transcatheter aortic valve replacement in low-risk patients, and percutaneous mitral or tricuspid valve interventions. Preventative cardiology data included the use of sodium-glucose cotransporter 2 (SGLT2) inhibitors (dapagliflozin), proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors (evolocumab), bempedoic acid, and novel approaches to the management of hypertension. Antiplatelet data included trials evaluating both the optimal length of course and combination of antiplatelet agents and regimes including combination antithrombotic therapies for patients with atrial fibrillation. Heart failure data included trials of sacubitril-valsartan in heart failure with preserved ejection fraction and the use of SGLT2 inhibitors in patients with heart failure but without diabetes. Electrophysiology data included trials examining alcohol in atrial fibrillation and the use of wearable fitness devices for identifying atrial fibrillation.

CONCLUSION

This article presents key clinical trials completed during 2019 and should be valuable to clinicians and researchers working in cardiology.