Improving efficiency and operator proficiency during percutaneous coronary interventions utilizing a standardized optical coherence tomography workflow.

Objectives: This study was designed to compare efficiency and quality metrics between percutaneous coronary intervention (PCI) procedures using optical coherence tomography (OCT) guided by a variable workflow versus a standardized workflow in a real-world population.

Background: The LightLab (LL) Initiative was designed to evaluate the impact of a standardized OCT workflow during PCI to address barriers to adoption.

Methods: The LL Initiative was a multicenter, prospective, observational study.

Safety and efficiency of percutaneous coronary intervention using a standardised optical coherence tomography workflow.

Background: While intravascular imaging guidance during percutaneous coronary intervention (PCI) improves outcomes, routine intravascular imaging usage remains low, in part due to perceived inefficiency and safety concerns.  Aims: The LightLab (LL) Initiative was designed to evaluate whether implementing a standardised optical coherence tomography (OCT) workflow impacts PCI safety metrics and procedural efficiency.

Methods: In this multicentre, prospective, observational study, PCI procedural data were collected over 2 years from 45 physicians at 17 US centres.

Mechanical stress-induced hemolysis of bovine blood is donor-dependent.

Introduction: In vitro hemolysis testing is an essential method for assessing the hemolytic potential of blood pumps, but has poor reproducibility. Further investigations are needed to determine the sources and extent of variability and to find a practical way to reduce the variation.

Methods: A small volume blood circulating loop driven by a Centrimag pump was established to provide relatively higher hemolysis readouts within a short run time and to be able to sequentially perform multiple repeated hemolysis tests in a working day.

Comparison of Angiographic and Intravascular Ultrasound Vessel Measurements in Infra-Popliteal Endovascular Interventions: The Below-the-Knee Calibration Study.

Background: Endovascular revascularization (ER) via percutaneous transluminal angioplasty (PTA) and stenting are viable options for revascularization in below-the-knee (BTK) peripheral arterial disease. Two-dimensional angiography has been the standard of practice for estimating vessel size and selecting treatment devices during ER. However, in other vascular territories, intravascular ultrasound (IVUS) offers better visualization of the lumen dimensions.

Design Effect of Metallic (Durable) and Polymeric (Resorbable) Stents on Blood Flow and Platelet Activation.

Bioresorbable vascular scaffolds (BVS) provide transient vessel support for occluded coronary arteries while resorbing over time, potentially allowing vessel restoration approximating the native, healthy state. Clinical trials indicate that the Absorb BVS (Abbott Vascular, Santa Clara, CA) performance was similar to that of the Xience metallic drug-eluting stent (DES), with low long-term complications rates. However, when under-deployed in very small vessels (diameter < 2.

Evaluation of chemical stability of polymers of XIENCE everolimus-eluting coronary stents in vivo by pyrolysis-gas chromatography/mass spectrometry.

The polymers poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(n-butyl methacrylate) (PBMA) are employed in manufacturing the XIENCE family of coronary stents. PBMA serves as a primer and adheres to both the stent and the drug coating. PVDF-HFP is employed in the drug matrix layer to hold the drug everolimus on the stent and control its release.

Design Principles of Bioresorbable Polymeric Scaffolds.

The concept for a bioresorbable vascular scaffold combines the best features of the first 3 generations of percutaneous coronary intervention (namely), balloon angioplasty, bare metallic stents, and drug-eluting stents, into a single device. The principles of operation of a BRS follow 3 phases of functionality that reflect the different physiologic requirements over time; revascularization, restoration, and resorption. Most BRS designs make use of the continuum of hydrolytic degradation in aliphatic polyesters, such as poly(l-lactide), in which molecular weight, strength, and mass decrease progressively in 3 distinct stages, consistent with the in vivo requirements of each performance phase.

Lessons Learned Regarding Handling and Deployment of the Absorb Bioresorbable Vascular Scaffold in Infrapopliteal Arteries.

Purpose: To describe relevant technical details with which to facilitate safe and effective use of the Absorb coronary bioresorbable vascular scaffold (BVS) in lower extremity arteries.

Technique: The Absorb BVS is a balloon-expandable, poly-l-lactide structure covered in a poly-d,l-lactide bioresorbable polymer that contains the antiproliferative drug everolimus. As a polymeric structure, it has a number of unique physical, handling, and imaging properties that may differ from metallic stents and pose a challenge to the interventionist.

Paving the way to a bioresorbable technology: Development of the absorb BRS program.

Bioresorbable scaffolds (BRS) combine attributes of the preceding generations of percutaneous coronary intervention (PCI) devices with new technologies to result in a novel therapy promoted as being the fourth generation of PCI. By providing mechanical support and drug elution to suppress restenosis, BRS initially function similarly to drug eluting stents. Thereafter, through their degradation, BRS undergo a decline in radial strength, allowing a gradual transition of mechanical function from the scaffold back to the artery in order to provide long term effectiveness similar to balloon angioplasty.

The BVS concept. From the chemical structure to the vascular biology: the bases for a change in interventional cardiology.

Bioresorbable vascular scaffolds (BVS), the fourth generation of percutaneous coronary intervention (PCI), aim to improve the long-term outcomes of PCI facilitating the restoration of the physiology of the treated vessels when the scaffold dismantling process is completed. In this paper we will review all the technical aspects as well as the potential clinical indications of this technology.

Relation Between Bioresorbable Scaffold Sizing Using QCA-Dmax and Clinical Outcomes at 1 Year in 1,232 Patients From 3 Study Cohorts (ABSORB Cohort B, ABSORB EXTEND, and ABSORB II).

Objectives: This study sought to investigate the clinical outcomes based on the assessment of quantitative coronary angiography-maximal lumen diameter (Dmax).

Background: Assessment of pre-procedural Dmax of proximal and distal sites has been used for Absorb scaffold size selection in the ABSORB studies.

Methods: A total of 1,248 patients received Absorb scaffolds in the ABSORB Cohort B (ABSORB Clinical Investigation, Cohort B) study (N = 101), ABSORB EXTEND (ABSORB EXTEND Clinical Investigation) study (N = 812), and ABSORB II (ABSORB II Randomized Controlled Trial) trial (N = 335).

Long-term safety of an everolimus-eluting bioresorbable vascular scaffold and the cobalt-chromium XIENCE V stent in a porcine coronary artery model.

Background: The Absorb everolimus-eluting bioresorbable vascular scaffold (Absorb) has shown promising clinical results; however, only limited preclinical data have been published. We sought to investigate detailed pathological responses to the Absorb versus XIENCE V (XV) in a porcine coronary model with duration of implant extending from 1 to 42 months.

Methods And Results: A total of 335 devices (263 Absorb and 72 XV) were implanted in 2 or 3 main coronary arteries of 136 nonatherosclerotic swine and examined by light microscopy, scanning electron microscopy, pharmacokinetics, and gel permeation chromatography analyses at various time points.

Lumen gain and restoration of pulsatility after implantation of a bioresorbable vascular scaffold in porcine coronary arteries.

Objectives: Using intravascular ultrasound (IVUS) and histomorphometry, this study sought to evaluate the potential of nonatherosclerotic porcine coronary arteries to undergo progressive lumen gain and a return of pulsatility after implantation with an everolimus-eluting bioresorbable vascular scaffold (BVS).

Background: Unique benefits such as lumen gain and restored vasomotion have been demonstrated clinically after treatment with BVS; however, a more rigorous demonstration of these benefits with a randomized clinical trial has not yet been conducted.

Methods: Seventy nonatherosclerotic swine received 109 everolimus-eluting BVS and 70 everolimus-eluting metal stents randomized among the main coronary arteries.

Intracoronary optical coherence tomography and histology of overlapping everolimus-eluting bioresorbable vascular scaffolds in a porcine coronary artery model: the potential implications for clinical practice.

Objectives: This study sought to assess the vascular response of overlapping Absorb stents compared with overlapping newer-generation everolimus-eluting metallic platform stents (Xience V [XV]) in a porcine coronary artery model.

Background: The everolimus-eluting bioresorbable vascular scaffold (Absorb) is a novel approach to treating coronary lesions. A persistent inflammatory response, fibrin deposition, and delayed endothelialization have been reported with overlapping first-generation drug-eluting stents.

In vivo characterisation of bioresorbable vascular scaffold strut interfaces using optical coherence tomography with Gaussian line spread function analysis.

Aims: Optical coherence tomography (OCT) of a bioresorbable vascular scaffold (BVS) produces a highly reflective signal outlining struts. This signal interferes with the measurement of strut thickness, as the boundaries cannot be accurately identified, and with the assessment of coverage, because the neointimal backscattering convolutes that of the polymer, frequently making them indistinguishable from one another. We hypothesise that Gaussian line spread functions (LSFs) can facilitate identification of strut boundaries, improving the accuracy of strut thickness measurements and coverage assessment.

Spatial distribution and temporal evolution of scattering centers by optical coherence tomography in the poly(L-lactide) backbone of a bioresorbable vascular scaffold.

Background: Scattering centers (SC) are often observed with optical coherence tomography (OCT) in some struts of bioresorbable vascular scaffolds (BVS). These SC might be caused by crazes in the polymer during crimp-deployment (more frequent at inflection points) or by other processes, such as physiological loading or hydrolysis (eventually increasing with time). The spatial distribution and temporal evolution of SC in BVS might help to understand their meaning.

Setting acceptance criteria for validation of analytical methods of drug eluting stents: Minimum requirements for analytical variability.

Accuracy and reliability of the analytical results are crucial for ensuring quality, safety and efficacy of drug eluting stents (DESs). Method validation is the process used to confirm that the analytical procedure employed for a specific test is suitable for its intended use. Results from method validation can be used to judge the quality, reliability and consistency of analytical results.

In vivo evaluation of stent strut distribution patterns in the bioabsorbable everolimus-eluting device: an OCT ad hoc analysis of the revision 1.0 and revision 1.1 stent design in the ABSORB clinical trial.

Aims: The ABSORB Cohort A clinical study has shown the feasibility and safety of the fully bioabsorbable everolimus-eluting structure (BVS, revision 1.0). However, the study also demonstrated somewhat higher acute and late recoil with the BVS structure compared to metallic drug eluting stents.

Design principles and performance of bioresorbable polymeric vascular scaffolds.

Aims: Bioresorbable polymeric vascular scaffolds may spawn a fourth revolution in percutaneous coronary intervention (PCI) and a novel treatment termed vascular restoration therapy. The principal design considerations for bioresorbable scaffolds are discussed in the context of physiological behaviour using the Bioabsorbable Vascular Solutions (BVS) ABSORB Cohort B scaffold (Abbott Vascular) as an example.

Methods And Results: The lifecycle of a bioresorbable scaffold is divided into three phases: (1) revascularisation; (2) restoration; and (3) resorption.