A prospective multicenter validation study for a novel angiography-derived physiological assessment software: Rationale and design of the radiographic imaging validation and evaluation for Angio-iFR (ReVEAL iFR) study.

Angiography-derived physiological assessment of coronary lesions has emerged as an alternative to wire-based assessment aiming at less-invasiveness and shorter procedural time as well as cost effectiveness in physiology-guided decision making. However, current available image-derived physiology software have limitations including the requirement of multiple projections and are time consuming. METHODS/DESIGN: The ReVEAL iFR (Radiographic imaging Validation and EvALuation for Angio-iFR) trial is a multicenter, multicontinental, validation study which aims to validate the diagnostic accuracy of the Angio-iFR medical software device (Philips, San Diego, US) in patients undergoing angiography for Chronic Coronary Syndrome (CCS). The Angio-iFR will enable operators to predict both the iFR and FFR value within a few seconds from a single projection of cine angiography by using a lumped parameter fluid dynamics model. Approximately 440 patients with at least one de-novo 40% to 90% stenosis by visual angiographic assessment will be enrolled in the study. The primary endpoint is the sensitivity and specificity of the iFR and FFR for a given lesion compared to the corresponding invasive measures. The enrollment started in August 2019, and was completed in March 2021. SUMMARY: The Angio-iFR system has the potential of simplifying physiological evaluation of coronary stenosis compared with available systems, providing estimates of both FFR and iFR. The ReVEAL iFR study will investigate the predictive performance of the novel Angio-iFR software in CCS patients. Ultimately, based on its unique characteristics, the Angio-iFR system may contribute to improve adoption of functional coronary assessment and the workflow in the catheter laboratory.

Quantitative Assessment of Acute Regurgitation Following TAVR: A Multicenter Pooled Analysis of 2,258 Valves.

OBJECTIVES: The aim of this study was to assess acute regurgitation following transcatheter aortic valve replacement, comparing different implanted transcatheter heart valves. BACKGROUND: Regurgitation following transcatheter aortic valve replacement influences all-cause mortality. Thus far, no quantitative comparison of regurgitation among multiple commercially available transcatheter heart valves has been performed. METHODS: Aortograms from a multicenter cohort of consecutive 3,976 transcatheter aortic valve replacements were evaluated in this pooled analysis. A total of 2,258 (58.3%) were considered analyzable by an independent academic core laboratory using video densitometry. Results of quantitative regurgitation are shown as percentages. The valves evaluated were the ACURATE (n = 115), Centera (n = 11), CoreValve (n = 532), Direct Flow Medical (n = 21), Evolut PRO (n = 95), Evolut R (n = 295), Inovare (n = 4), Lotus (n = 546), Lotus Edge (n = 3), SAPIEN XT (n = 239), and SAPIEN 3 (n = 397). For the main analysis, only valves with more than 50 procedures (7 types) were used. RESULTS: The Lotus valve had the lowest mean regurgitation (3.5 ± 4.4%), followed by Evolut PRO (7.4 ± 6.5%), SAPIEN 3 (7.6 ± 7.1%), Evolut R (7.9 ± 7.4%), SAPIEN XT (8.8 ± 7.5%), ACURATE (9.6 ± 9.2%) and CoreValve (13.7 ± 10.7%) (analysis of variance p < 0.001). The only valves that statistically differed from all their counterparts were Lotus (as the lowest regurgitation) and CoreValve (the highest). The proportion of patients presenting with moderate or severe regurgitation followed the same ranking order: Lotus (2.2%), Evolut PRO (5.3%), SAPIEN 3 (8.3%), Evolut R (8.8%), SAPIEN XT (10.9%), ACURATE (11.3%), and CoreValve (30.1%) (chi-square p < 0.001). CONCLUSIONS: In this pooled analysis stemming from daily clinical practice, the Lotus valve was shown to have the best immediate sealing. This analysis reflects the objective evaluation of regurgitation by an academic core laboratory (nonsponsored) in a real-world cohort of patients using a quantitative technique.

Preclinical evaluation of a thin-strut bioresorbable scaffold (ArterioSorb): acute-phase invasive imaging assessment and hemodynamic implication.

AIMS: The aim of this study was to assess the acute performance of the 95 µm ArterioSorb oriented poly L-lactic acid (PLLA) scaffold in comparison with the XIENCE metallic drug-eluting stent (DES) in porcine coronary arteries. METHODS AND RESULTS: In 15 non-atherosclerotic Yucatan mini pigs, the ArterioSorb (3.0/14 mm) and XIENCE (3.0/15 mm) were implanted in 25 and 15 vessels, respectively. Acute performance was evaluated by using quantitative coronary angiography (QCA) and optical coherence tomography (OCT). Following three-dimensional reconstruction of the coronary arteries, endothelial shear stress (ESS) was quantified using non-Newtonian steady-flow simulation. Acute recoil measured by QCA was comparable in the two arms. Post-procedural flow and scaffold/stent area by OCT did not differ between the two devices. ESS post procedure was comparable between ArterioSorb and XIENCE (2.21±1.97 vs 2.25±1.71 Pa, p=0.314). CONCLUSIONS: Acute recoil, luminal dimensions and ESS in the ArterioSorb oriented PLLA scaffold with thin struts of 95 µm were comparable to those in the XIENCE metallic DES.

What does the future hold for novel intravascular imaging devices: a focus on morphological and physiological assessment of plaque.

INTRODUCTION: It is well recognized that a lesion that does not cause a hemodynamically significant stenosis can trigger a sudden cardiac event through plaque rupture. As a diagnostic tool, intravascular imaging was developed to circumvent limitations of coronary angiography; however, none of the intravascular imaging devices are individually able to provide complete assessment of the plaque morphology, geometry, physiology and biology. Therefore, over the past few years an effort was made to develop hybrid intravascular imaging catheters to provide more complete evaluation of coronary plaque pathobiology. Areas covered: This paper aims to give an overview of the recent developments on 1) single-modality intravascular imaging devices; 2) hybrid intravascular imaging devices and 3) the hemodynamic analysis in models reconstructed from the fusion of intravascular imaging and angiographic data. Expert commentary: Within five years, most of the hybrid imaging techniques which are now in pre-clinical phase will be utilized in the clinical arena, as NIRS-IVUS. Software for online blood simulation is likely to be developed that will enable ESS calculation while the patient is in the catheterization laboratory.

Quantitative assessment of the stent/scaffold strut embedment analysis by optical coherence tomography.

The degree of stent/scaffold embedment could be a surrogate parameter of the vessel wall-stent/scaffold interaction and could have biological implications in the vascular response. We have developed a new specific software for the quantitative evaluation of embedment of struts by optical coherence tomography (OCT). In the present study, we described the algorithm of the embedment analysis and its reproducibility. The degree of embedment was evaluated as the ratio of the embedded part versus the whole strut height and subdivided into quartiles. The agreement and the inter- and intra-observer reproducibility were evaluated using the kappa and the interclass correlation coefficient (ICC). A total of 4 pullbacks of OCT images in 4 randomly selected coronary lesions with 3.0 × 18 mm devices [2 lesions with Absorb BVS and 2 lesions with XIENCE (both from Abbott Vascular, Santa Clara, CA, USA)] from Absorb Japan trial were evaluated by two investigators with QCU-CMS software version 4.69 (Leiden University Medical Center, Leiden, The Netherlands). Finally, 1481 polymeric struts in 174 cross-sections and 1415 metallic struts in 161 cross-sections were analyzed. Inter- and intra-observer reproducibility of quantitative measurements of embedment ratio and categorical assessment of embedment in Absorb BVS and XIENCE had excellent agreement with ICC ranging from 0.958 to 0.999 and kappa ranging from 0.850 to 0.980. The newly developed embedment software showed excellent reproducibility. Computer-assisted embedment analysis could be a feasible tool to assess the strut penetration into the vessel wall that could be a surrogate of acute injury caused by implantation of devices.

Is there a need for dedicated devices?

Although the provisional approach is recommended over a systematic two-stent approach in bifurcation lesions, an a priori two-stent approach may be considered in certain specific anatomies in a minority of cases. Virtual bench test and intravascular imaging studies have provided essential insights into the technical aspects of bifurcation stenting and led to recommendations on how to optimise both the provisional and the two-stent strategies. Dedicated bifurcation stents may further optimise the procedural and clinical outcomes of both strategies. However, randomised data are sparse and more randomised trials are needed to provide evidence as to whether these dedicated devices will indeed improve procedural and clinical outcomes.

Comparison between two- and three-dimensional quantitative coronary angiography bifurcation analyses for the assessment of bifurcation lesions: A subanalysis of the TRYTON pivotal IDE coronary bifurcation trial.

BACKGROUND: Three-dimensional (3D) quantitative coronary angiography (QCA) provides more accurate measurements by minimizing inherent limitations of two-dimensional (2D) QCA. The aim of this study was to compare the measurements between 2D and 3D QCA analyses in bifurcation lesions. METHODS AND RESULTS: A total of 114 cases with non-left main bifurcation lesions in the TRYTON pivotal IDE Coronary Bifurcation Trial (ClinicalTrials.gov: NCT01258972) were analyzed using a validated bifurcation QCA software (CAAS 5.10, Pie Medical Imaging, Maastricht, the Netherlands). All cases were analyzed in matched projections between pre- and post-procedure. The 2D analysis was performed using one of two angiographic images used for 3D reconstruction showing a larger distal bifurcation angle. In the treated segments (stent and balloon), there were no differences in minimal luminal diameter (MLD) between 2D and 3D, while diameter stenosis (DS) was significantly higher in 2D compared to 3D both pre-procedure and post-procedure (53.9% for 2D vs. 52.1% for 3D pre-procedure, P < 0.01; 23.2% for 2D vs. 20.9% for 3D post-procedure, P = 0.01). In the sub-segment level analysis, lengths of proximal main branch, distal main branch, and side branch were consistently shorter in 2D compared to 3D both pre-procedure and post-procedure. Using 3D QCA, the anatomic location of the smallest MLD or the highest DS was relocated to a different bifurcation sub-segment in a considerable proportion of the patients compared to when 2D-QCA was used (kappa values: 0.50 for MLD, 0.55 for DS). CONCLUSIONS: Our data showed differences in addressing anatomical severity and location of coronary bifurcation lesions between in vivo 2D and 3D QCA analyses. More studies are needed to investigate potential clinical benefits in using 3D approach over 2D QCA for the assessment of bifurcation lesions.

Assessment of coronary atherosclerosis progression and regression at bifurcations using combined IVUS and OCT.

OBJECTIVES: The aim of this study was to evaluate the progression of atherosclerotic coronary plaques at bifurcations, using combined intravascular ultrasound-virtual histology (IVUS-VH) and optical coherence tomography (OCT). BACKGROUND: Pathological findings reveal that atherosclerotic plaques characterized by the presence of large necrotic cores (NCs) with fibrous cap thicknesses < 65 µm are more prone to rupture. Accuracy in the detection of high-risk plaques could be improved by the combined use of IVUS-VH and OCT. METHODS: IVUS-VH and OCT are 2 imaging modalities with different lateral resolutions and different depths of penetration. To provide a precise matching of the images, bifurcations were used as landmarks. IVUS-VH and OCT were performed in 56 bifurcations from 24 patients at baseline and at 6-month follow-up. All patients were treated with standard medical therapy. Bifurcations were studied at the proximal, in-bifurcation, and distal regions. Plaques were classified according to their composition as assessed by IVUS-VH and fibrous cap thickness as quantified by OCT. RESULTS: At baseline, 27 NC-rich plaques were found. At 6-month follow-up, 22 (81%) did not show any significant change. Four new NC-rich lesions developed. At both time points, percent NC was higher and the fibrous cap was thinner at the proximal bifurcation rim compared with the distal. There were no significant changes in percent NC and fibrous cap thickness in the 3 bifurcation regions between baseline and follow-up examinations. No major cardiovascular events due to bifurcation lesion progression were observed. CONCLUSIONS: The combined use of IVUS-VH and OCT is a reliable tool to serially assess plaque progression and regression, and in the present study it was demonstrated to be safe and feasible. At 6-month follow-up, in this post-percutaneous coronary intervention patient population, most high-risk plaques remained unchanged, retaining their imaging classifications, nevertheless appearing to have remained clinically silent.

3-Dimensional optical coherence tomography assessment of jailed side branches by bioresorbable vascular scaffolds: a proposal for classification.

OBJECTIVES: The purpose of this study is to assess jailing of side branches (SB) by the everolimus-eluting, bioresorbable vascular scaffold (BVS) with 3-dimensional (3D) optical coherence tomography (OCT) reconstruction. BACKGROUND: Because BVS struts at the SB orifice are suspected of being bioresorbed and/or forming a neointimal bridge, OCT has been used to evaluate the struts in detail at that particular site. Our understanding of the 3D relationship of the strut and the SB orifice is limited by the use of 2-dimensional OCT images. Fourier-domain OCT enables reliable 3D reconstruction of coronary vessels. METHODS: The ABSORB Cohort B (A Clinical Evaluation of the Bioabsorbable Everolimus Eluting Coronary Stent System in the Treatment of Patients With de Novo Native Coronary Artery Lesions) trial is a multicenter single-arm trial to assess the safety and performance of the BVS. Fourier-domain OCT pullbacks (C7-XR system, LightLab Imaging Inc., Westford, Massachusetts) are obtained at pullback speed of 20 mm/s and 3D renderings are performed. The orifices of the SB are assessed visually. The area of SB orifice and the number of strut-free compartments delineated by the BVS struts are evaluated. RESULTS: Fifty-one OCT pullbacks were acquired: 33 pullbacks were imaged with Fourier-domain OCT and 27 treated segments had 46 side branches. Three-dimensional assessment was feasible in 87% (40 of 46) of pullbacks. The mean area of the SB orifice was 1.16 +/- 1.02 mm(2). The mean number of strut-free compartments was 2.0 +/- 1.1. The classification of the overhanging struts is proposed. CONCLUSIONS: This study demonstrates that 3D OCT reconstruction is feasible to evaluate the orifices of SB jailed with BVS. (ABSORB Clinical Investigation, Cohort B; NCT00856856).

Value of the SYNTAX score for risk assessment in the all-comers population of the randomized multicenter LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) trial.

OBJECTIVES: We aimed to assess the predictive value of the SYNTAX score (SXscore) for major adverse cardiac events in the all-comers population of the LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) trial. BACKGROUND: The SXscore has been shown to be an effective predictor of clinical outcomes in patients with multivessel disease undergoing percutaneous coronary intervention. METHODS: The SXscore was prospectively collected in 1,397 of the 1,707 patients enrolled in the LEADERS trial (patients after surgical revascularization were excluded). Post hoc analysis was performed by stratifying clinical outcomes at 1-year follow-up, according to 1 of 3 SXscore tertiles. RESULTS: The 1,397 patients were divided into tertiles based on the SXscore in the following fashion: SXscore8 and 16 (SXhigh) (n=461). At 1-year follow-up, there was a significantly lower number of patients with major cardiac event-free survival in the highest tertile of SXscore (SXlow=92.2%, SXmid=91.1%, and SXhigh=84.6%; p<0.001). Death occurred in 1.5% of SXlow patients, 2.1% of SXmid patients, and 5.6% of SXhigh patients (hazard ratio [HR]: 1.97, 95% confidence interval [CI]: 1.29 to 3.01; p=0.002). The myocardial infarction rate tended to be higher in the SXhigh group. Target vessel revascularization was 11.3% in the SXhigh group compared with 6.3% and 7.8% in the SXlow and SXmid groups, respectively (HR: 1.38, 95% CI: 1.1 to 1.75; p=0.006). Composite of cardiac death, myocardial infarction, and clinically indicated target vessel revascularization was 7.8%, 8.9%, and 15.4% in the SXlow, SXmid, and SXhigh groups, respectively (HR: 1.47, 95% CI: 1.19 to 1.81; p<0.001). CONCLUSIONS: The SXscore, when applied to an all-comers patient population treated with drug-eluting stents, may allow prospective risk stratification of patients undergoing percutaneous coronary intervention. (LEADERS Trial Limus Eluted From A Durable Versus ERodable Stent Coating; NCT00389220).

Optical coherence tomography for the assessment of pericardium covered stents for the treatment of degenerated saphenous vein grafts.

AIMS: Pre- and post-interventional optical coherence tomography (OCT) assessment of degenerated saphenous vein grafts (SVG) treated with implantation of pericardium covered stents. Percutaneous treatment of SVG represents one of the major challenges of current percutaneous coronary interventions (PCI). Artificial membrane-covered stents have failed to show additional benefit over conventional stents. METHODS AND RESULTS: Six cases of PCI of de novo lesions in degenerated SVGs were successfully treated with a novel pericardium covered stent (PCS). Successful deployment was achieved in all cases. Large emboli were retrieved in a distal filter in one case with a long degenerated lesion. Pre- and postinterventional OCT was performed to assess the lesion characteristics and vessel diameter before stenting and the pericardium layer integrity, strut apposition and presence of plaque prolapse after stenting. In order to better understand the OCT images, three PCS of different diameters were deployed in silicone tubes of 700 microm thickness wall with inner tube diameter matching the stent diameter. OCT was repeated after spreading a thin layer of gel inside the tube, mimicking the toothpaste-like plaque observed in SVG. In vivo and in vitro OCT images excluded the presence of plaque prolapse in all but one case and detected a characteristic pattern with bulging of the pericardium between struts, possibly due to trapping of soft intraluminal plaque (or gel) behind the pericardial layer. CONCLUSIONS: These cases offer insight into the mechanism of protection against distal embolisation, elucidated by the appearance of these stents after deployment in vivo and in vitro.

Assessment of in-stent restenosis using 64-MDCT: analysis of the CORE-64 Multicenter International Trial.

OBJECTIVE: Evaluations of stents by MDCT from studies performed at single centers have yielded variable results with a high proportion of unassessable stents. The purpose of this study was to evaluate the accuracy of 64-MDCT angiography (MDCTA) in identifying in-stent restenosis in a multicenter trial. MATERIALS AND METHODS: The Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography Using 64 Detectors (CORE-64) Multicenter Trial and Registry evaluated the accuracy of 64-MDCTA in assessing 405 patients referred for coronary angiography. A total of 75 stents in 52 patients were assessed: 48 of 75 stents (64%) in 36 of 52 patients (69%) could be evaluated. The prevalence of in-stent restenosis by quantitative coronary angiography (QCA) in this subgroup was 23% (17/75). Eighty percent of the stents were or=50% stenosis by QCA was 0.25 (p=0.073). Quantitative assessment failed to improve the accuracy of MDCT over qualitative assessment. CONCLUSION: The results of our study showed that 64-MDCT has poor ability to detect in-stent restenosis in small-diameter stents. Evaluability and negative predictive value were better in large-diameter stents. Thus, 64-MDCT may be appropriate for stent assessment in only selected patients.