Implicancias de la inteligencia artificial en los métodos de imagen endovascular / Implications of Artificial Intelligence in Intravascular Imaging Methods

RESUMEN La angioplastia transluminal coronaria (ATC) es una de las principales estrategias de revascularización en pacientes con enfermedad coronaria aterosclerótica (ECA). Numerosos estudios respaldan la optimización de la ATC mediante métodos de imagen endovascular; sin embargo, estos métodos son subutilizados en la práctica clínica contemporánea y enfrentan desafíos en la interpretación de los datos obtenidos, por lo que la integración de la inteligencia artificial (IA) se vislumbra como una solución atractiva para promover y simplificar su uso. La IA se define como un programa computarizado que imita la capacidad del cerebro humano para recopilar y procesar datos. El aprendizaje de máquinas es una subdisciplina de la IA que implica la creación de algoritmos capaces de analizar grandes conjuntos de datos sin suposiciones previas, mientras que el aprendizaje profundo se centra en la construcción y entrenamiento de redes neuronales artificiales profundas y complejas. Así, se ha demostrado que la incorporación de sistemas de IA a los métodos de imagen endovascular incrementa la precisión de la ATC, disminuye el tiempo del procedimiento y la variabilidad interobservador en la interpretación de los datos obtenidos, promueve así una mayor adopción y facilita su utilización. El propósito de la presente revisión es destacar cómo los sistemas actuales basados en IA pueden desempeñar un papel fundamental en la interpretación de los datos generados por los métodos de imagen endovascular, lo que conduce a una mejora en la optimización de la ATC en pacientes con ECA.

ABSTRACT Percutaneous coronary intervention (PCI) is one of the primary revascularization strategies in patients with coronary artery disease (CAD). Several studies support the use of intravascular imaging methods to optimize PCI. However, these methods are underutilized in contemporary clinical practice and face challenges in data interpretation. Therefore, the incorporation of artificial intelligence (AI) is seen as an attractive solution to promote and simplify their use. AI can be defined as a computer program that mimics the human brain in its ability to collect and process data. Machine learning is a sub-discipline of AI that involves the creation of algorithms capable of analyzing large datasets without making prior assumptions, while deep learning focuses on the construction and training of deep and complex artificial neural networks. The incorporation of AI systems to intravascular imaging methods improves the accuracy of PCI, reduces procedure duration, and minimizes interobserver variability in data interpretation. This promotes their wider adoption and facilitates their use. The aim of this review is to highlight how current AI-based systems can play a key role in the interpretation of data generated by intravascular imaging methods and optimize PCI in patients with CAD.

Impact of endothelial shear stress on absorption process of resorbable magnesium scaffold: A BIOSOLVE-II substudy

BACKGROUND/PURPOSE: Local hemodynamic forces such as endothelial shear stress (ESS) may have an influence on appropriate neointimal healing, vessel remodeling, and struts absorption process following second-generation drug-eluting resorbable magnesium scaffold (RMS, Magmaris, Biotronik AG, Buelach, Switzerland) placement. The aim of this study was to investigate the impact of ESS assessed by optical coherence tomography (OCT)- based computational fluid dynamic (CFD) simulations on absorption process and coronary lumen dimension after Magmaris implantation. METHODS AND RESULTS: A total of 22 patients who were enrolled in the BIOSOLVE-II trial and underwent serial OCT assessment immediately after Magmaris implantation and at 6- and 12-month follow-up were included. We evaluated qualitative OCT findings frame by frame, and CFD simulations were performed to calculate the ESS at 3-dimensional (3D) reconstructed arteries. For quantitative calculation, the average ESS within each 1-mm section was classified into three groups: low (2.5 Pa). A significant difference of percentage remnants of scaffold was observed among the 3 groups at 12-month follow-up (P = 0.001) but not at 6-month follow-up. Low-ESS segment at baseline resulted in a greater lumen change of −1.857 ± 1.902 mm2 at 1 year compared to −1.277 ± 1.562 mm2 in the intermediate-ESS segment (P = 0.017) and − 0.709 ± 1.213 mm2 in the high-ESS segment (P = 0.001). CONCLUSION: After Magmaris implantation, the presence of higher ESS might be associated with slower strut absorption process but less luminal loss. SUMMARY FOR TABLE OF CONTENTS: The authors analyzed 22 patients from the BIOSOLVE-II trial who underwent optical coherence tomography assessment immediately after receiving a Magmaris second-generation drug-eluting resorbable magnesium scaffold. The analysis found that after Magmaris implantation, the presence of higher endothelial shear stress (ESS) might be associated with slower strut absorption process but less luminal loss. This study is the first demonstrating the impact of ESS assessed by OCT on absorption process and coronary lumen dimension after Magmaris implantation.

Impact of procedural characteristics on coronary vessel wall healing following implantation of second-generation drug-eluting absorbable metal scaffold in patients with de novo coronary artery lesions: an optical coherence tomography analysis

AIMS : Second-generation drug-eluting absorbable metal scaffold (DREAMS 2G) is an alternative novel device for treating coronary lesions. However, the relationship between in-scaffold dimensions after implantation of DREAMS 2G and vessel healing and luminal results at follow-up is unknown. The aim of this study is, therefore, to investigate whether the expansion index after implantation of DREAMS 2G as assessed by optical coherence tomography (OCT) impacts late luminal status and healing of the vessel wall. METHODS AND RESULTS : This study comprises of a total 65 out of 123 patients who were enrolled in the BIOSOLVE-II trial. We assessed both qualitative and quantitative OCT findings and the expansion index of DREAMS 2G after implantation frame by frame using OCT. Expansion index was defined as minimum scaffold area/mean reference lumen area. The over-expansion group was also defined with expansion index >1.0. The total number of analyzed frames at post-procedure and 6-month follow-up was 8243 and 8263 frames, respectively. At 6-month follow-up, in-scaffold healing was documented by the reduction of 82% in dissections, 93% in attached intra-luminal mass (ILM), 65% in non-attached ILM, and 76% in jailed side branch. The over-expansion group had significantly greater in-scaffold luminal volume loss (LVL) compared with the non-over-expansion group [over-expansion: 35.0 (18.5-52.1) mm3 vs. non-over-expansion: 21.0 (11.6-37.9) mm3, P = 0.039]. CONCLUSION : Excellent in vivo healing process after implantation of DREAMS 2G was observed at 6 months. We found that higher expansion indices were associated with higher in-scaffold LVL at 6 months assessed by OCT. (AU)

Standardized classification and framework for reporting, interpreting, and analysing medication non-adherence in cardiovascular clinical trials: a consensus report from the Non-adherence Academic Research Consortium (NARC)

Non-adherence has been well recognized for years to be a common issue that significantly impacts clinical outcomes and health care costs. Medication adherence is remarkably low even in the controlled environment of clinical trials where it has potentially complex major implications. Collection of non-adherence data diverge markedly among cardiovascular randomized trials and, even where collected, is rarely incorporated in the statistical analysis to test the consistency of the primary endpoint(s). The imprecision introduced by the inconsistent assessment of non-adherence in clinical trials might confound the estimate of the calculated efficacy of the study drug. Hence, clinical trials may not accurately answer the scientific question posed by regulators, who seek an accurate estimate of the true efficacy and safety of treatment, or the question posed by payers, who want a reliable estimate of the effectiveness of treatment in the marketplace after approval. The Non-adherence Academic Research Consortium is a collaboration among leading academic research organizations, representatives from the U.S. Food and Drug Administration and physician-scientists from the USA and Europe. One in-person meeting was held in Madrid, Spain, culminating in a document describing consensus recommendations for reporting, collecting, and analysing adherence endpoints across clinical trials. The adoption of these recommendations will afford robustness and consistency in the comparative safety and effectiveness evaluation of investigational drugs from early development to post-marketing approval studies. These principles may be useful for regulatory assessment, as well as for monitoring local and regional outcomes to guide quality improvement initiatives.(AU)

First report of edge vascular response at 12 months of Magmaris, a second-generation drug-eluting resorbable magnesium scaffold, assessed by grayscale intravascular ultrasound, virtual histology, and optical coherence tomography. A biosolve-II trial sub-study

Introduction and objective: The edge vascular response (EVR) remains unknown in second generation drugeluting Resorbable Magnesium Scaffold (RMS), such as Magmaris. The aim of the study was to evaluate tissue modifications in the RMS edges over time, assessed by different invasive imaging modalities. Methods: The patients treated with the device were assessed by optical coherence tomography (OCT), grayscale intravascular ultrasound (IVUS), and virtual histology IVUS at baseline and 12 months. The EVR study performed a segment- and frame-level analysis of the 5 mm segments proximal and distal of the actual RMS. Results: The segment-level grayscale IVUS (n=10), virtual histology IVUS (n=10), and OCT (n=18) analysis did not showany significant changes after 12months, except for a fibrous plaque area (FPA) reduction of 0.5mm2 (p=0.017) in the proximal segment compared to baseline. In the frame-level analysis, IVUS evaluation revealed a vessel area decreased 2.80 ± 1.43 mm2 (p = 0.012) and 2.49 ± 1.53 mm2 (p = 0.022) in 2 proximal frames. This was accompanied by plaque area reduction of 0.88 ± 0.70 mm2 (p = 0.048) and a FPA decreased by 0.63 ± 0.48mm2 (p = 0.004) in one proximal frame. In 1 distal frame, there was a dense calcium area reduction of 0.10 ± 0.12 mm2 (p = 0.045), FPA and fibrous fatty plaque increased 0.54 ± 0.53 mm2 (p = 0.023) and 0.17 ± 0.16 mm2 (p = 0.016), respectively. By OCT, there was a lumen area decrease of 0.76 ± 1.51 mm2 (p = 0.045) in a distal frame. Conclusion: At 12 months, Magmaris EVR assessment does not show overall significant changes, except for a fibrous plaque area reduction in the proximal segment. This could be translated as a benign healing process a the edges of the RMS. Summary: The edge vascular response (EVR) remains unknown in second generation drug-eluting absorbable metal scaffolds (RMS), such as Magmaris. Patients treated with the device were assessed by multi invasive imagingmodalities [i.e. optical coherence tomography (OCT), grayscale intravascular ultrasound (IVUS), and virtual histology IVUS] evaluating the tissue changes over timein the segment- and frame-level analysis of the 5mm segments proximal and distal of the actual RMS. As a result, after 12months, Magmaris EVR assessment does not show overall significant changes, except for a fibrous plaque area reduction in the proximal segment, translating a benign healing process at the edges of the RMS.

Serial 3 dimensional optical coherence tomography assessment of jailed side branch by second-generation drug-eluting absorbable metal scaffold (from the BIOSOLVE-II Trial)

Second-generation drug-eluting absorbable metal scaffold (DREAMS 2G) is used for treating coronary lesions. However, the natural history of the jailed side-branch (SB) after DREAMS 2G implantation remains to be elucidated. The aim of this study is to investigate the effect of scaffold struts on jailed SBs as assessed by 3-dimensional (3D) optical coherence tomography (OCT) after implantation of DREAMS 2G. We enrolled the patients who received a DREAMS 2G implantation and where OCT was performed at postprocedure and 12-month follow-up in the BIOSOLVE-II trial. The area of the ostium of jailed SBs and number of compartments divided by scaffold struts were assessed by cut-plane analysis using 3D OCT. A total of 24 patients with 61 jailed SBs were analyzed in this study. The number of compartments was significantly decreased (postprocedure; 1.98 +/- 0.84 vs 12 months; 1.10 +/- 0.30, p <0.001) during the 12 months. Since most of the struts disappeared, the ostium area was increased in 62% of jailed SBs at 12 months, however, not significantly different from postprocedure (postprocedure; 0.74 [0.34 to 1.46] mm(2) vs 12 months; 0.78 [0.41 to 1.68] mm(2), p=0.055). The number of compartments created by scaffold struts and branching angle at postprocedure had no effect on the changes of SB ostium área. DREAMS 2G has a favorable absorption process in the jailed SBs up to 12 months and may be considered as an optional therapy for treating lesions that involve SBs. (AU)

Safety and clinical performance of a drug eluting absorbable metal scaffold in the treatment of subjects with de novo lesions in native coronary arteries: Pooled 12-month outcomes of BIOSOLVE-II and BIOSOLVE-III

OBJECTIVES: Based on outcomes of the BIOSOLVE-II study, a novel second generation drug eluting absorbable metal scaffold gained CE-mark in 2016. The BIOSOLVE-III study aimed to confirm these outcomes and to obtain additional 12-month angiographic data. BACKGROUND: Bioresorbable scaffolds are intended to overcome possible long-term effects of permanent stents such as chronic vessel wall inflammation, stent crushing, and fractures. METHODS: The prospective, multicenter BIOSOLVE-II and BIOSOLVE-III studies enrolled 184 patients with 189 lesions (123 patients in BIOSOLVE-II and 61 patients in BIOSOLVE-III). Primary endpoints were in-segment late lumen loss at 6 months (BIOSOLVE-II) and procedural success (BIOSOLVE-III). RESULTS: Mean patient age was 65.5 6 10.8 years and mean lesion reference diameter was 2.70 6 0.43 mm. In BIOSOLVE-III, there were significantly more type B2/C lesions than in BIOSOLVE-II (80.3% versus 43.4%, P < 0.0001) and significantly more moderate-to-severe calcifications (24.2% versus 10.7%, P 5 0.014). At 12 months, there was no difference in late lumen loss between the two studies; in the overall population, it was 0.25 6 0.31 mm in-segment and 0.396 0.34 mm in scaffold. Target lesion failure occurred in six patients (3.3%) and included two cardiac deaths, one target-vessel myocardial infarction, and three clinically driven target lesion revascularizations. No definite or probable scaffold thrombosis was observed. CONCLUSION: The pooled outcomes of BIOSOLVE-II and BIOSOLVE-III provide further evidence on the safety and performance of a novel drug-eluting absorbable metal scaffold with constant clinical and angiographic performance parameters at 12 months and no definite or probable scaffold thrombosis.

Adiponectin in Relation to Coronary Plaque Characteristics on Radiofrequency Intravascular Ultrasound and Cardiovascular Outcome / Relação da Adiponectina com as Características da Placa Aterosclerótica ao Ultrassom Intravascular com Radiofrequência e Desfechos Cardiovasculares

Abstract Background: Prospective data on the associations of adiponectin with in-vivo measurements of degree, phenotype and vulnerability of coronary atherosclerosis are currently lacking. Objective: To investigate the association of plasma adiponectin with virtual histology intravascular ultrasound (VH-IVUS)-derived measures of atherosclerosis and with major adverse cardiac events (MACE) in patients with established coronary artery disease. Methods: In 2008-2011, VH-IVUS of a non-culprit non-stenotic coronary segment was performed in 581 patients undergoing coronary angiography for acute coronary syndrome (ACS, n = 318) or stable angina pectoris (SAP, n = 263) from the atherosclerosis-intravascular ultrasound (ATHEROREMO-IVUS) study. Blood was sampled prior to coronary angiography. Coronary plaque burden, tissue composition, high-risk lesions, including VH-IVUS-derived thin-cap fibroatheroma (TCFA), were assessed. All-cause mortality, ACS, unplanned coronary revascularization were registered during a 1-year-follow-up. All statistical tests were two-tailed and p-values < 0.05 were considered statistically significant. Results: In the full cohort, adiponectin levels were not associated with plaque burden, nor with the various VH-tissue types. In SAP patients, adiponectin levels (median[IQR]: 2.9(1.9-3.9) µg/mL) were positively associated with VH-IVUS derived TCFA lesions, (OR[95%CI]: 1.78[1.06-3.00], p = 0.030), and inversely associated with lesions with minimal luminal area (MLA) ≤ 4.0 mm2 (OR[95%CI]: 0.55[0.32-0.92], p = 0.025). In ACS patients, adiponectin levels (median[IQR]: 2.9 [1.8-4.1] µg/mL)were not associated with plaque burden, nor with tissue components. Positive association of adiponectin with death was present in the full cohort (HR[95%CI]: 2.52[1.02-6.23], p = 0.045) and (borderline) in SAP patients (HR[95%CI]: 8.48[0.92-78.0], p = 0.058). In ACS patients, this association lost statistical significance after multivariable adjustment (HR[95%CI]: 1.87[0.67-5.19], p = 0.23). Conclusion: In the full cohort, adiponectin levels were associated with death but not with VH-IVUS atherosclerosis measures. In SAP patients, adiponectin levels were associated with VH-IVUS-derived TCFA lesions. Altogether, substantial role for adiponectin in plaque vulnerability remains unconfirmed.

Resumo Fundamento: Faltam dados prospectivos sobre as associações de adiponectina com medidas in-vivo de grau, fenótipo e vulnerabilidade da aterosclerose coronariana. Objetivo: Investigar a associação da adiponectina plasmática com medidas de aterosclerose derivadas de ultrassonografia virtual intravascular (VH-IVUS) e eventos cardíacos adversos importantes (major adverse cardiac events - MACE) em pacientes com doença arterial coronariana estabelecida. Métodos: Em 2008-2011, a VH-IVUS de um segmento coronariano não estenótico não culpado foi realizado em 581 pacientes submetidos à angiografia coronariana para síndrome coronariana aguda (SCA, n = 318) ou angina pectoris estável (APE, n = 263) a partir do estudo de ultrassonografia aterosclerótica-intravascular (ATHEROREMO-IVUS). Sangue foi amostrado antes da angiografia coronária. Foram avaliados a carga de placa coronária, a composição tecidual, as lesões de alto risco, incluindo fibroateroma de capa fina (FCF) derivado de VH-IVUS. Mortalidade por todas as causas, SCA, e revascularização coronária não planejada foram registradas durante um ano de acompanhamento. Todos os testes estatísticos foram bicaudais e os valores de p < 0,05 foram considerados estatisticamente significativos. Resultados: Na coorte completa, os níveis de adiponectina não foram associados à carga de placa, nem a vários tipos de tecido virtual histológico. Entre os pacientes com APE, os níveis de adiponectina (mediana[IIQ]: 2,9(1,9-3,9) µg/mL) foram associados positivamente às lesões FCF derivadas de VH-IVUS, (OR[IC 95%]: 1,78[1,06-3,00], p = 0,030), e inversamente associados a lesões com área luminal mínima (ALM) ≤4,0 mm2 (OR[IC 95%]: 0,55[0,32-0,92], p = 0,025). Em pacientes com SCA, os níveis de adiponectina (mediana[IIQ]: 2,9 [1,8-4,1] µg/mL) não foram associados à carga de placa nem a componentes teciduais. A associação positive de adiponectina ao óbito esteve presente na coorte completa (HR[IC 95%]: 2,52[1,02-6,23], p = 0,045) e (limítrofe) em pacientes com APE (HR[IC 95%]: 8,48[0,92-78,0], p = 0,058). Entre pacientes com SCA, essa associação perdeu significância estatística após ajuste multivariado (HR[IC 95%]: 1,87[0,67-5,19], p = 0,23). Conclusão: Na coorte completa, os níveis de adiponectina foram associados à obito, mas não a medidas de aterosclerose por VH-IVUS. Em pacientes com APE, os níveis de adiponectina foram associados a lesões FCF derivadas de VH-IVUS. Em geral, o papel da adiponectina na vulnerabilidade da placa permanece não confirmado.

In vivo serial invasive imaging of the second-generation drug-eluting absorbable metal scaffold (Magmaris — DREAMS 2G) in de novo coronary lesions: Insights from the BIOSOLVE-II First-In-Man Trial

RATIONALE: Bioresorbable scaffolds may confer clinical benefit in long-term studies; early mechanistic studies using intravascular imaging have provided insightful information about the immediate and mid-term local serial effects of BRS on the coronary vessel wall. OBJECTIVES: We assessed baseline, 6- and 12-month imaging data of the drug-eluting absorbable metal scaffold (DREAMS 2G). METHODS AND RESULTS: The international, first-in-man BIOSOLVE-II trial enrolled 123 patients with up to 2 de novo lesions (in vessels of 2.2 to 3.7mm). Angiographic based vasomotion, curvature and angulation were assessed; intravascular ultrasound (IVUS) derived radiofrequency (RF) data analysis and echogenicity were evaluated; optical coherence tomography (OCT) attenuation and backscattering analysis were also performed. There was hardly any difference in curvature between pre-procedure and 12months (-0.0019; p=0.48). The change in angulation from pre- to 12months was negligible (-3.58°; 95% CI [-5.97, -1.20]), but statistically significant. At 6months, the change in QCA based minimum lumen diameter in response to high dose of acetylcholine and IVUS-RF necrotic core percentage showed an inverse relationship (estimate of -0.489; p=0.055) and with fibrous volume a positive relationship (estimate of 0.53, p=0.035). Bioresorption analysis by OCT showed that the maximum attenuation values decreased significantly from post-procedure at 6months (Δ 6months vs. post-proc. is -13.5 [95% CI -14.6, -12.4]) and at 12months (Δ 12months vs. post-proc. is -14.0 [95% CI -15.4, -12.6]). By radiofrequency data, the percentage of dense calcium decreased significantly from post-procedure at 6months and at 12months...

Sustained safety and clinical performance of a drug-eluting absorbable metal scaffold up to 24 months: pooled outcomes of BIOSOLVE-II and BIOSOLVE-III

AIMS: We aimed to assess the safety and performance of the DREAMS 2G scaffold up to 24 months post implant. METHODS AND RESULTS: The present study population comprises a total of 184 patients with 189 lesions who were enrolled in the prospective, multicentre BIOSOLVE-II and BIOSOLVE-III trials. Clinical follow-up was scheduled at one, six, 12, 24 and 36 months. The present report includes pooled follow-up data at six months and BIOSOLVE-II data at 24 months. Patients were 65.5±10.8 years old, and lesions were 12.5±5.1 mm long with reference diameters of 2.7±0.4 mm. Procedural success was obtained in 97.8%. At six months, the composite clinical endpoint target lesion failure was 3.3% (95% CI: 1.2-7.1), based on two cardiac deaths (1.1%, one unknown and one not device-related), one target vessel myocardial infarction (0.6%), and three clinically driven target lesion revascularisations (1.7%). For BIOSOLVE-II at 24 months, the target lesion failure rate was 5.9% (95% CI: 2.4-11.8), based on two cardiac deaths (1.7%), one target vessel myocardial infarction (0.9%) and four target lesion revascularisations (3.4%). There was no definite or probable scaffold thrombosis...

Sustained safety and performance of the second-generation drug-eluting absorbable metal scaffold in patients with de novo coronary lesions: 12-month clinical results and angiographic findings of the BIOSOLVE-II first-in-man trial

Aims: Metal absorbable scaffolds constitute a conceptually attractive alternative to polymeric scaffolds. Promising 6-month outcomesof a second-generation drug-eluting absorbable metal scaffold (DREAMS 2G), consisting of an absorbable magnesiumscaffold backbone, have been reported. We assessed the 12-month safety and performance of this novel device. Methods and results: The prospective, international, multi-centre, first-in-man BIOSOLVE-II trial enrolled 123 patients with up to two de novolesions with a reference diameter between 2.2 and 3.7 mm. All patients were scheduled for angiographic follow-up at6 months, and—if subjects consented—at 12 months. Dual antiplatelet therapy was recommended for 6 months. Quantitative coronary angiography (QCA) parameters remained stable from 6 to 12 months [paired data of 42patients: in-segment late lumen loss 0.20 + 0.21 mm vs. 0.25 + 0.22 mm, P » 0.117, D 0.05 + 0.21 mm (95%CI: 20.01;0.12); in-scaffold late lumen loss 0.37 + 0.25 mm vs. 0.39 +0.27 mm, P » 0.446, D 0.03 + 0.22 (95%CI: 20.04;0.10), respectively]. Intravascular ultrasound and optical coherence tomography findings corroboratedthe QCA results. Target lesion failure occurred in four patients (3.4%), consisting of one death of unknown cause,one target-vessel myocardial infarction, and two clinically driven target lesion revascularization. No additional eventoccurred beyond the 6-month follow-up. During the entire follow-up of 12 months, none of the patients experienceda definite or probable scaffold thrombosis...

Safety and performance of the second-generation drug-eluting absorbable metal scaffold in patients with de-novo coronary artery lesions (BIOSOLVE-II): 6 month results of a prospective, multicentre, non-randomised, first-in-man trial

Background Absorbable scaffolds were designed to overcome the limitations of conventional, non-absorbable metal-based drug-eluting stents. So far, only polymeric absorbable scaffolds are commercially available. We aimed to assess the safety and performance of a novel second-generation drug-eluting absorb...

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)

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). The incidence of major adverse cardiac events (MACE) (a composite of cardiac death, any myocardial infarction [MI], and ischemia-driven target lesion revascularization) was analyzed according to the Dmax subclassification of scaffold oversize group versus scaffold nonoversize group...

Lessons learned from acute and late scaffold failures in the ABSORB EXTEND trial

Aims: Bioresorbable scaffolds are increasingly used in patients with coronary artery disease undergoing percutaneouscoronary interventions. ABSORB EXTEND is an ongoing study that will recruit 800 patients. Thisreport evaluates acute and late scaffold failure in the first 450 patients enrolled in ABSORB EXTEND whohave completed 12 months follow-up.Methods and results: Clinical event data from the first 450 patients enrolled in ABSORB EXTEND havedemonstrated low rates of ischaemia-driven MACE (4.2%) and target vessel failure (4.7%) at 12 months.There have been seven cases of device failure in this study: three cases of scaffold dislodgement (0.67%) andfour cases of subacute or late scaffold thrombosis (0.89%). All scaffold dislodgements occurred in the leftcircumflex (LCX), and in two cases dislodgement was observed after reinsertion of the same device. Twocases of subacute scaffold thrombosis and two late scaffold thromboses were observed. Two out of four casesof scaffold thrombosis seemed to be related to either premature discontinuation of dual antiplatelet therapy(DAPT) or resistance to clopidogrel.Conclusions: This is the first report specifically describing the incidence and the potential mechanisms ofscaffold dislodgement and scaffold thrombosis as seen in the ABSORB EXTEND trial.

Proximal and distal maximal luminal diameters as a guide to appropriate deployment of the ABSORB everolimus-eluting bioresorbable vascular scaffold: a sub-study of the ABSORB Cohort B and the on-going ABSORB EXTEND single arm study

Objectives: Due to the limited distensibility of the everolimus-eluting bioresorbablevascular scaffold (ABSORB) compared to metallic platform stents, quantitative coronaryarteriography (QCA) is a mandatory requirement for ABSORB deployment in theon-going ABSORB EXTEND Single-Arm Study. Visual assessment of vessel size in theABSORB Cohort B study often lead to under and over-sizing of the 3 mm ABSORB incoronary vessels (recommended range of the vessel diameter 2.5 mm and 3.3 mm),with an increased risk of spontaneous incomplete scaffold apposition post ABSORBdeployment. We report whether mandatory QCA assessment of vessel size pre-implantation,utilizing the maximal luminal diameter (Dmax) and established interpolatedreference vessel diameter (RVD) measurements, has improved device/vessel sizing.Methods: Pre-implantation post-hoc QCA analyses of all 101 patients from ABSORBCohort B (102 lesions) and first consecutive 101 patients (108 lesions) from ABSORBEXTEND were undertaken by an independent core-laboratory; all patients had a 3 mmABSORB implanted. Comparative analyses were performed. Results: Within ABSORBCohort B, a greater number of over-sized vessels (>3.3 mm) were identified utilizingthe Dmax compared to the interpolated RVD (17 vessels, 16.7% vs. 3 vessels, 2.9%; P 50.002). Comparative analyses demonstrated a greater number of appropriate vessel-sizeselection (75 vessels, 69.4% vs. 48 vessels, 47.1%; P 5 0.001), a trend towards a reductionin implantation in small (3.3 mm) vessels(4 vessels, 3.7% vs. 17 vessels, 16.7%; P 5 0.002) in ABSORB EXTEND. Bland–Altmanplots suggested a good agreement between operator and core-laboratory calculatedDmax measurements. Conclusions: ...

Assessment of drug-eluting stents and bioresorbable stentsby grayscale IVUS and IVUS-based imaging modalities

Abstract Grayscale IVUS and IVUS-based imagingmodalities during the last years have becomeuseful in the assessment not only of drug elutingstent, but also of new bioresorbable vascular scaffolds.Although IVUS resolution is not sufficient fordetermining stent coverage (optical coherence tomographyis the gold standard), serial IVUS can measureintimal hyperplasia, assess acute and late incompletestent apposition, detect the presence and persistenceof edge dissections, study edge effects and look forcauses of restenosis and thrombosis. In addition otherIVUS-based imaging modalities, such as IVUS-VH,iMAP or palpography, can be used to study the serialcompositional and mechanical changes of the plaquebehind stent struts and also to follow the bioresorptionof the new bioresorbable scaffolds, analyzing thebackscattering signal coming from the polymericstruts. This review details and evaluates grayscaleIVUS and IVUS-based techniques findings in clinicaltrials, highlighting the usefulness of these imagingmodalities in the study of drug eluting stents andbioresorbable vascular scaffold.

Precisión diagnóstica de la angiografía coronaria por tomografía computarizada multislice aplicada al "mundo real" / Diagnostic accuracy of coronary angiography with multislice computed tomography

Objetivo: Evaluar la precisión diagnóstica de la angiografía coronaria por tomografía computarizada multislice (ACTCM) para la detección de estenosis significativas en arterias coronarias. Material y métodos: Se estudiaron pacientes con indicación de cinecoronariografía diagnóstica sin antecedentes de alergia al contraste, insuficiencia renal ni arritmias. Para la adquisición de imágenes se utilizó un tomógrafo multislice (multicorte) (Brilliance 40, Philips, The Netherlands) gatillado electrocardiográficamente. Se administraron 90-125 ml de contraste yodado por vía endovenosa. La obesidad, la diabetes, los segmentos difusamente calcificados, con diámetro < 2,0 mm, y aquellos tratados con stents no constituyeron criterios de exclusión. Las lesiones se definieron significativas cuando presentaron una reducción luminal ≥ 50 por ciento por ACTCM y angiografía cuantitativa coronaria (QCA). Resultados: Previo a la intervención se escanearon 38 pacientes. De ellos, uno (3 por ciento) fue excluido debido a calidad de imagen insuficiente. Los 37 restantes (444 segmentos), con calidad de scan satisfactoria, se incluyeron en el estudio (81 por ciento hombres, edad media 62,43 ± 12,5 años, 13,5 por ciento diabéticos). El tiempo medio de scan fue de 15,12 ± 2,6 segundos. Se analizaron 444 segmentos por ambas técnicas. Se encontraron 88 (17 por ciento) y 93 (18 por ciento) lesiones significativas por CCG y ACTCM, respectivamente. La sensibilidad, la especificidad, el valor predictivo positivo y el valor predictivo negativo de la ACTCM para detectar estenosis significativas fueron del 82 por ciento, 93 por ciento, 72 por ciento y 96 por ciento, respectivamente. Conclusión: En pacientes seleccionados para cinecoronariografía, la angiografía coronaria por tomografía computarizada multislice presenta un alto valor predictivo negativo para la detección de enfermedad obstructiva coronaria.

Drug-eluting stents

Stent implantation was developed to overcome the acute recoil and high restenosis rate of balloon angioplasty, but resulted in the development of chronic in-stent restenosis related to specific factors regarding patient, stent, lesion and procedural characteristics. Some factors are not modifiable, such as patient and lesion characteristics, whereas procedural characteristics may be improved by better implantation technique and stent design. Drug-eluting stents are a novel approach in stent technology and design with local drug delivery to inhibit intimal thickening by interfering with different pathways involved in the development of inflammation, migration, proliferation and/or secretion of the extracellular matrix. Both the drug and the delivery vehicle must fulfill pharmacological, pharmacokinetic and mechanical requirements. Current successful drug eluting stents require a polymer coating for drug delivery. Clinical trials examining several pharmaceutical agents, particularly sirolimus and paclitaxel, have demonstrated marked reduction in restenosis following stenting. Sirolimus is a natural macrocyclic lactone and paclitaxel is a cytotoxic agent against many tumors. Both compounds block cell cycle progression and thus inhibit smooth muscle cell proliferation. The development of drug-eluting stents is one of the major revolutions in the field of Interventional Cardiology. Restenosis rate has been significantly reduced, in comparison to bare metal stents. The ideal drug to prevent restenosis must have an anti-proliferative and anti-migratory effect on smooth muscle cells but on the other hand must also enhance re-endothelialization, in order to prevent late thrombosis. Additionally, it should effectively inhibit the anti-inflammatory response after balloon induced arterial injury. Currently sirolimus, paclitaxel and more recently, ABT-578-eluting stents are commercially available, but ongoing research and clinical trials will result in new stents coming to market with novel designs loaded with a variety of compounds. As drug-eluting stent implantation becomes more liberal leading to an extensive use of this technology, the problem of restenosis in drug-eluting stents will become more common. However, for the time being, little is known regarding optimal treatment of in-stent restenosis following drug-eluting stent implantation. Future research is mandatory to further clarify, whether these patients should be treated with the same drug-eluting sten.