Impact of myocardial bridging on coronary artery plaque formation and long-term mortality after heart transplantation.

Objectives: This study aimed to explore the impact of myocardial bridging (MB) on early development of cardiac allograft vasculopathy and long-term graft survival after heart transplantation.

Background: MB has been reported to be associated with acceleration of proximal plaque development and endothelial dysfunction in native coronary atherosclerosis. However, its clinical significance in heart transplantation remains unclear.

Impact of Diastolic Vessel Restriction on Quality of Life in Symptomatic Myocardial Bridging Patients Treated With Surgical Unroofing: Preoperative Assessments With Intravascular Ultrasound and Coronary Computed Tomography Angiography.

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Head-to-head comparison of quantitative measurements between intravascular imaging systems: An in vitro phantom study.

Introduction: The present study aimed to compare the accuracy of quantitative measurements by contemporary intravascular imaging systems including optical frequency domain imaging (OFDI), frequency domain optical coherence tomography (FD-OCT), and 6 intravascular ultrasound (IVUS) systems.

Methods: We imaged five cylindrical phantom models made from an acrylic resin with known lumen diameters (1.51, 2.

Intravascular ultrasound predictors of long-term outcomes following ABSORB bioresorbable scaffold implantation: A pooled analysis of the ABSORB III and ABSORB Japan trials.

Background: The long-term prognostic impact of IVUS findings following Absorb BVS implantation remains uncertain. This study aimed to identify the IVUS predictors of long-term clinical outcomes following ABSORB bioresorbable vascular scaffold (BVS) implantation from the pooled IVUS substudy cohorts of the ABSORB III and Japan trials.

Methods: A total of 298 lesions in 286 patients were enrolled with 2:1 randomization to ABSORB BVS vs.

Deep learning-based intravascular ultrasound segmentation for the assessment of coronary artery disease.

Background: Accurate segmentation of the coronary arteries with intravascular ultrasound (IVUS) is important to optimize coronary stent implantation. Recently, deep learning (DL) methods have been proposed to develop automatic IVUS segmentation. However, most of those have been limited to segmenting the lumen and vessel (i.

Scaffold underexpansion and late lumen loss after bioresorbable scaffold implantation: Insights from ABSORB JAPAN trial.

Background: Device underexpansion is associated with late adverse outcomes after bioresorbable vascular scaffold (BVS) implantation. This study, representing official IVUS results of the ABSORB Japan trial, aimed to characterize IVUS findings, focusing specifically on acute device expansion, and to investigate its impact on late lumen loss (LLL) with Absorb-BVS compared with cobalt-chromium everolimus-eluting stents (CoCr-EES).

Methods: ABSORB Japan enrolled 148 patients (2:1 randomization) in the IVUS cohort.

Validated model of platelet slip at stenosis and device surfaces.

Platelets are central to thrombosis. However, it is unknown whether platelets slip at vascular or device surfaces. The presence of platelet slip at a surface would interrupt physical contact between the platelet and that surface, and therefore diminish adhesion and thrombosis.

Early invasive assessment of the coronary microcirculation predicts subsequent acute rejection after heart transplantation.

Background: Acute allograft rejection (AAR) plays an important role in patient and graft survival; therefore, more emphasis should be placed on its prediction. This study aimed to investigate baseline clinical and diagnostic variables associated with subsequent AAR during the first year post-transplant, especially focusing on early physiologic and anatomic measures.

Methods: This study enrolled 88 heart transplant patients who underwent fractional flow reserve (FFR), coronary flow reserve (CFR), the index of microcirculatory resistance (IMR) and intravascular ultrasound (IVUS) in the left anterior descending artery at baseline (within 8 weeks post-transplant).

Bioresorbable Scaffold for Treatment of Coronary Artery Lesions: Intravascular Ultrasound Results From the ABSORB Japan Trial.

Objectives: The aim of this study was to characterize post-procedural intravascular ultrasound (IVUS) findings in the ABSORB Japan trial, specifically stratified by the size of target coronary arteries.

Background: Despite overall noninferiority confirmed in recent randomized trials comparing bioresorbable vascular scaffolds (BVS) (Absorb BVS) and cobalt-chromium everolimus-eluting metallic stents (CoCr-EES), higher event rates of Absorb BVS have been reported with suboptimal deployment, especially in small coronary arteries.

Methods: In the ABSORB Japan trial, 150 patients (2:1 randomization) were scheduled in the IVUS cohort.

Impact of Stent Size Selection on Acute and Long-Term Outcomes After Drug-Eluting Stent Implantation in De Novo Coronary Lesions.

Background: Although significant undersizing often results in incomplete stent apposition or underexpansion, the possible impact of oversized stent implantation on arterial wall injury has not been systematically investigated with drug-eluting stents. The aim of this study was to investigate the impact of stent oversizing on acute and long-term outcomes after drug-eluting stents implantation in de novo coronary lesions.

Methods And Results: Serial (baseline and 6-12 months) coronary angiography and intravascular ultrasound were performed in 2931 lesions treated with drug-eluting stents (355 sirolimus, 846 paclitaxel, 1387 zotarolimus, and 343 everolimus).

Assessment of bioresorbable scaffold with a novel high-definition 60 MHz IVUS imaging system: Comparison with 40-MHz IVUS referenced to optical coherence tomography.

Background: In vivo assessment of bioresorbable scaffold (BRS) is of growing clinical interest. The novel 60MHz high-definition intravascular ultrasound (HD-IVUS) has been developed to overcome the limitations of conventional 40 MHz IVUS. This study aimed to evaluate the performance and limitations of 60 MHz HD-IVUS compared with 40 MHz IVUS with respect to polymeric-strut visualization, quantitative and qualitative analysis, and feasibility of high-speed pullback in the assessment of BRS.

Needs-Based Innovation in Interventional Radiology: The Biodesign Process.

There are many possible mechanisms for innovation and bringing new technology into the marketplace. The Stanford Biodesign innovation process is based in a deep understanding of clinical unmet needs as the basis for focused ideation and development. By identifying and vetting a compelling unmet need, the aspiring innovator can "derisk" a project and maximize chances for successful development in an increasingly challenging regulatory and economic environment.

The effect of negative remodeling on fractional flow reserve after cardiac transplantation.

Background: Negative remodeling is a common occurrence early after cardiac transplantation. Its impact on the development of myocardial ischemia is not well documented. The aim of this study is to investigate the impact of negative remodeling on fractional flow reserve after cardiac transplantation.

Impact of attenuated-signal plaque observed by intravascular ultrasound on vessel response after drug-eluting stent implantation.

Background And Aims: The aim of this study was to investigate the impact of attenuated-signal plaque (ASP) observed by intravascular ultrasound (IVUS) on vessel response after drug-eluting stent implantation.

Methods: Data were derived from the IVUS cohort of the J-DESsERT trial comparing paclitaxel- and sirolimus-eluting stents. Serial IVUS analysis (pre- and post-intervention, and 8-month follow-up) was performed in 136 non-AMI lesions.

The Impact of Postgraduate Health Technology Innovation Training: Outcomes of the Stanford Biodesign Fellowship.

Stanford Biodesign launched its Innovation Fellowship in 2001 as a first-of-its kind postgraduate training experience for teaching biomedical technology innovators a need-driven process for developing medical technologies and delivering them to patients. Since then, many design-oriented educational programs have been initiated, yet the impact of this type of training remains poorly understood. This study measures the career focus, leadership trajectory, and productivity of 114 Biodesign Innovation Fellowship alumni based on survey data and public career information.

Needs-Based Innovation in Cardiovascular Medicine: The Stanford Biodesign Process.

More than a decade ago, a formalized fellowship training program in medical device innovation, the first of its kind, was created at Stanford University. Now in its 15th year, the Stanford Biodesign Fellowship Program is a 10-month program whereby postgraduate students with a prior background in medicine, engineering, and/or business form interdisciplinary teams for an experiential process of identifying unmet clinical needs, inventing new solutions, and implementing these ideas (the 3 "I's"). A key component of this structured process is focused attention on needs finding and characterization, which differs from the traditional "tech-push" model (i.

Attenuated-Signal Plaque Progression Predicts Long-Term Mortality After Heart Transplantation: IVUS Assessment of Cardiac Allograft Vasculopathy.

Background: Although cardiac allograft vasculopathy (CAV) is typically characterized by diffuse coronary intimal thickening with pathological vessel remodeling, plaque instability may also play an important role in CAV. Previous studies of native coronary atherosclerosis have demonstrated associations between attenuated-signal plaque (ASP), plaque instability, and adverse clinical events.

Objectives: This study's aim was to characterize the association between ASP and long-term mortality post-heart transplantation.

Multimodality Molecular Imaging of Cardiac Cell Transplantation: Part II. In Vivo Imaging of Bone Marrow Stromal Cells in Swine with PET/CT and MR Imaging.

Purpose To quantitatively determine the limit of detection of marrow stromal cells (MSC) after cardiac cell therapy (CCT) in swine by using clinical positron emission tomography (PET) reporter gene imaging and magnetic resonance (MR) imaging with cell prelabeling. Materials and Methods Animal studies were approved by the institutional administrative panel on laboratory animal care. Seven swine received 23 intracardiac cell injections that contained control MSC and cell mixtures of MSC expressing a multimodality triple fusion (TF) reporter gene (MSC-TF) and bearing superparamagnetic iron oxide nanoparticles (NP) (MSC-TF-NP) or NP alone.

Multimodality Molecular Imaging of Cardiac Cell Transplantation: Part I. Reporter Gene Design, Characterization, and Optical in Vivo Imaging of Bone Marrow Stromal Cells after Myocardial Infarction.

Purpose To use multimodality reporter-gene imaging to assess the serial survival of marrow stromal cells (MSC) after therapy for myocardial infarction (MI) and to determine if the requisite preclinical imaging end point was met prior to a follow-up large-animal MSC imaging study. Materials and Methods Animal studies were approved by the Institutional Administrative Panel on Laboratory Animal Care. Mice (n = 19) that had experienced MI were injected with bone marrow-derived MSC that expressed a multimodality triple fusion (TF) reporter gene.

Acute stent recoil and optimal balloon inflation strategy: an experimental study using real-time optical coherence tomography.

Aims: Our aim was to evaluate stent expansion and acute recoil at deployment and post-dilatation, and the impact of post-dilatation strategies on final stent dimensions.

Methods And Results: Optical coherence tomography (OCT) was performed on eight bare metal platforms of drug-eluting stents (3.0 mm diameter, n=6 for each) during and after balloon inflation in a silicone mock vessel.

Functional Versus Anatomic Assessment of Myocardial Bridging by Intravascular Ultrasound: Impact of Arterial Compression on Proximal Atherosclerotic Plaque.

Background: The presence of a myocardial bridge (MB) has been shown to promote atherosclerotic plaque formation proximal to the MB, presumably because of hemodynamic disturbances provoked by retrograde blood flow toward this segment in cardiac systole. We aimed to determine the anatomic and functional properties of an MB related to the extent of atherosclerosis assessed by intravascular ultrasound.

Methods And Results: We enrolled 100 patients with angina but no significant obstructive coronary artery disease who had an intravascular ultrasound-detected MB in the left anterior descending artery (median age 54 years, 36% male).

Association of periarterial neovascularization with progression of cardiac allograft vasculopathy and long-term clinical outcomes in heart transplant recipients.

Background: This study investigated the relationship between periarterial neovascularization, development of cardiac allograft vasculopathy (CAV), and long-term clinical outcomes after heart transplantation. Proliferation of the vasa vasorum is associated with arterial inflammation. The contribution of angiogenesis to the development of CAV has been suggested.

Relative dose and vascular response after drug-eluting stent implantation: A dosimetric 3D-intravascular ultrasound study.

Background: In drug-eluting stents (DESs), the theoretical drug dose exposed to the vessel wall per stent surface area may vary due to the fixed loading dose and differences in the stent surface area once expanded in varying vessel sizes. The aim of this study was to evaluate the potential effects of different dose intensities, as estimated by 3D-IVUS dosimetry, on vascular response after DES implantation.

Methods: Follow-up (6-9 months) 3D-IVUS was performed in 840 coronary lesions treated with a single DES of the following types: sirolimus (SES, n=148), paclitaxel (PES, n=162), Endeavor zotarolimus (E-ZES, n=233), Resolute zotarolimus (R-ZES, n=147), and everolimus (EES, n=150).

Paradoxical Vessel Remodeling of the Proximal Segment of the Left Anterior Descending Artery Predicts Long-Term Mortality After Heart Transplantation.

Objectives: This study investigated the association between arterial remodeling and geographic distribution of cardiac allograft vasculopathy (CAV), and outcomes after heart transplantation.

Background: CAV is characterized by a combination of coronary intimal thickening and pathological vessel remodeling, which varies at different locations in coronary arteries.

Methods: In 100 transplant recipients, serial volumetric intravascular ultrasonography (IVUS) was performed at baseline and 1 year post-transplantation in the first 50 mm of the left anterior descending artery (LAD).

Quantitative precision of optical frequency domain imaging: direct comparison with frequency domain optical coherence tomography and intravascular ultrasound.

No systematic validation study is available with optical frequency domain imaging (OFDI), directly compared with frequency domain optical coherence tomography (FD-OCT) and intravascular ultrasound (IVUS). Controversy also remains about the impact of different stent contour tracing methods by OFDI/FD-OCT. In vitro: coronary phantom models (1.