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AIMS: Scaffold design and plaque characteristics influence implantation outcomes and local flow dynamics in treated coronary segments. Our aim is to assess the impact of strut embedment/protrusion of bioresorbable scaffold on local shear stress distribution in different atherosclerotic plaque types. METHODS AND RESULTS: Fifteen Absorb everolimus-eluting Bioresorbable Vascular Scaffolds were implanted in human epicardial coronary arteries. Optical coherence tomography (OCT) was performed post-scaffold implantation and strut embedment/protrusion were analysed using a dedicated software. OCT data were fused with angiography to reconstruct 3D coronary anatomy. Blood flow simulation was performed and wall shear stress (WSS) was estimated in each scaffolded surface and the relationship between strut embedment/protrusion and WSS was evaluated. There were 9083 struts analysed. Ninety-seven percent of the struts (n = 8840) were well-apposed and 243 (3%) were malapposed. At cross-section level (n = 1289), strut embedment was significantly increased in fibroatheromatous plaques (76 ± 48 µm) and decreased in fibrocalcific plaques (35 ± 52 µm). Compatible with strut embedment, WSS was significantly higher in lipid-rich fibroatheromatous plaques (1.50 ± 0.81 Pa), whereas significantly decreased in fibrocalcified plaques (1.05 ± 0.91 Pa). After categorization of WSS as low (<1.0 Pa) and normal/high WSS (≥1.0 Pa), the percent of low WSS in the plaque subgroups were 30.1%, 31.1%, 25.4%, and 36.2% for non-diseased vessel wall, fibrous plaque, fibroatheromatous plaque, and fibrocalcific plaque, respectively (P-overall < 0.001). CONCLUSION: The composition of the underlying plaque influences strut embedment which seems to have effect on WSS. The struts deeply embedded in lipid-rich fibroatheromas plaques resulted in higher WSS compared with the other plaque types.

It has been hypothesized that dedicated optimized Absorb BVS implantation techniques might mitigate the risk of adverse events such as target vessel f

We aimed to quantitatively assess a possible difference of the neointimal quality between biodegradable polymer- (BP-) and durable polymer drug-eluting stents (DP-DESs). We conducted a single-center all-comer prospective cohort study: the RESTORE registry (UMIN000033009). All patients who received successful OCT examination at planned 3-month follow-up after DES implantation were analyzed. Study population was divided into 2 groups, BP-DES versus DP-DES groups. We evaluated standard OCT variables, coverage percent, and the quantitative light property values including light intensity, attenuation, and backscatter. We performed OCT analyses of 121 lesions in 98 patients (BP-DES 55 lesions in 51 patients vs. DP-DES 66 lesions in DP-DES 53 patients). Lesion and procedural characteristics were overall well-balanced between both groups. At 3-month follow-up, neointimal thickness (BP-DES 49.3 [38.2, 57.7] µm versus DP-DES 54.7 [45.1, 70.7] µm, p = 0.059) and coverage percent (BP-DES 94.5 [89.8, 97.0]% vs. DP-DES 95.8 [91.1, 98.1]%, p = 0.083) did not significantly differ. Light intensity of superficial neointima in the BP-DES was lower than that in the DP-DES, whereas that of deep neointima did not differ between both groups.

Aims As a sine qua non for arterial wall physiology, local hemodynamic forces such as endothelial shear stress (ESS) may influence long-term vessel changes as bioabsorbable scaffolds dissolve. The aim of this study was to perform serial computational fluid dynamic (CFD) simulations to examine immediate and long-term haemodynamic and vascular changes following bioresorbable scaffold placement. Methods and results Coronary arterial models with long-term serial assessment (baseline and 5 years) were reconstructed through fusion of intravascular optical coherence tomography and angiography. Pulsatile non-Newtonian CFD simulations were performed to cal

To establish the accuracy of coronary computed tomography angiography (CTA) for in-scaffold quantitative evaluation with opti

Aims To compare the long-term safety and efficacy of bioresorbable vascular scaffold (BVS) with everolimus-eluting stent (EES) after percutaneous coronary interventions. Methods and results A systematic review and meta-analysis of randomized clinical trials comparing clinical outcomes of patients treated with BVS and EES with at least 24 months follow-up was performed. Adjusted random-effect model by the Knapp- Hartung method was used to compute odds ratios (OR) and 95% confidence intervals (CI). The primary safety outcome of interest was the risk of definite/probable device thrombosis (DT). The primary efficacy outcome of interest was the risk of target lesion failure (TLF). Five randomized clinical trials (n= 1730) were included. Patients treated with Absorb BVS had a higher risk of definite/probable DT compared with patients treated with EES (OR 2.93, 95%CI 1.37-6.26, P= 0.01). Very late DT (VLDT) occurred in 13 patients [12/996 (1.4%, 95%CI: 0.08-2.5) Absorb BVS vs. 1/701 (0.5%, 95%CI: 0.2-1.6) EES; OR 3.04; 95%CI 1.2-7.68, P = 0.03], 92% of the VLDT in the BVS group occurred in the absence of dual antiplatelet therapy (DAPT). Patients treated with Absorb BVS had a trend towards higher risk of TLF (OR 1.48, 95%CI 0.90-2.42, P= 0.09), driven by a higher risk of target vessel myocardial infarction and ischaemia-driven target lesion revascularization. No difference was found in the risk of cardiac death. Conclusion Compared with EES, the use of Absorb BVS was associated with a higher rate of DT and a trend towards higher risk of TLF. VLDT occurred in 1.4% of the patients, the majority of these events occurred in the absence of DAPT.

We realized that during the proof of our published article entitled “Assessment of the hemodynamic characteristics of Absorb BVS in a porcine coronary artery model” we made a mistake probably because of copy-paste process of the table sketch for Table 5b and Table 5c. We sincerely apologize for that mistake and kindly request from the journal to amend it. The authors would like to apologize for any inconvenience caused.

Background and aim Local hemodynamic changes are one of the main factors that determine the vessel wall biological response after stent/scaffold implantation. Computational fluid dynamic studies provide an opportunity to investigate the rheological effects of implanted stent

_Objectives:_ Little data are available to compare coronary artery bypass graft surgery (CABG) vs percutaneous coronary intervention (PCI) with drug-eluting stents (DES) in older adults. We evaluate the long-term outcomes of CABG vs PCI with DES in older adults with left main or multivessel coronary artery disease (CAD). _Design:_ Individual patient-level meta-analysis. _Settings:_ Databases from the BEST, PRECOMBAT, and SYNTAX trials were combined. _Participants:_ A total 1,079 adults aged 70 to 89 years were pooled. _Measurements:_ The primary outcome was a composite of death from any causes, myocardial infarction, stroke, or repeat revascularization. _Results:_ During a total of 6.3 (median, 4.9) years of follow-up, the primary composite outcome of all-cause mortality, myocardial infarction, stroke, or repeat revascularization occurred in 26% (141/550) and 34% (179/529) of patients in the CABG and PCI groups, respectively (hazard ratio (HR), 0.75; 95% confidence interval (CI), 0.60-0.94; P = .012). CABG was associated with fewer myocardial infarction (4% vs 8% for PCI; HR, 0.48; 95% CI, 0.29-0.80; P = .037); and repeat revascularizations (8% vs 17% for PCI; HR, 044; 95% CI, 0.31-0.64; P < .001), but had little association with all-cause mortality or stroke. _Conclusion:_ Older adults age 70 to 89 years with left main or multivessel CAD who

Underexpansion and overexpansion have been incriminated as causative factors of adverse cardiac events. However, dynamic biological interaction between vessel wall and scaffold may attenuate the adverse haemodynamic impact of overexpansion or underexpansion.

Aims: We aimed to investigate the impact of lesion calcification on angiographic outcomes after Absorb everolimus-eluting bioresorbable vascular scaffold (BVS) implantation in comparison with those after cobalt-chromium everolimus-eluting stent (CoCr-EES) implantation. Methods and results: The present post hoc analysis of the ABSORB Japan randomised trial compared post-procedure and 13-month angiographic outcomes between patients implanted with BVS and CoCr-EES based on the presence or absence of calcification, excluding extremely heavily calcified lesions or lesions requiring rotational atherectomy. The study population comprised 384 patients with 384 lesions (including 114 lesions [29.7%] with moderate or severe calcification), classified into two subgroups: calcification, 114 (BVS: n=72 and CoCr-EES: n=42) and non-calcification, 270 (BVS: n=181 and CoCr-EES: n=89). Follow-up angiography was performed in 94.8% of patients. Both post-procedure and follow-up indevice minimal lumen diameters were comparable in both the BVS arm (calcification vs. non-calcification: 2.43±0.32 mm vs. 2.43±0.39 mm, p=0.91 and 2.17±0.49 mm vs. 2.27±0.47 mm, p=0.17) and in the CoCr-EES arm (2.68±0.34 mm vs. 2.65±0.42 mm, p=0.62 and 2.57±0.52 mm vs. 2.47±0.53 mm, p=0.36). Conclusions: Moderate or severe lesion calcification (excluding patients with extremely heavily calcified lesions or lesions requiring rotational atherectomy) does not negatively affect angiographic outcomes at both post-procedure and 13-month follow-up after BVS implantation.

Aims: Patients with ST-segment elevation myocardial infarction (STEMI) feature thrombus-rich lesions with large necrotic core, which are usually associated with delayed arterial healing and impaired stent-related outcomes. The use of bioresorbable vascular scaffolds (Absorb) has the potential to overcome these limitations owing to restoration of native vessel lumen and physiology at long term. The purpose of this randomized trial was to compare the arterial healing response at short term, as a surrogate for safety and efficacy, between the Absorb and the metallic everolimus-eluting stent (EES) in patients with STEMI. Methods and results: ABSORB-STEMI TROFI II was a multicentre, single-blind, non-inferiority, randomized controlled trial. Patients with STEMI who underwent primary percutaneous coronary intervention were randomly allocated 1:1 to treatment with the Absorb

Aims: Fully bioresorbable Absorb poly-L-lactic-acid (PLLA) scaffolds (Abbott Vascular, Santa Clara, CA, USA) are a novel approach for the treatment of coronary narrowing. Due to the translucency of the material (PLLA), the optical coherence tomography (OCT) measurement methods used in the ABSORB trials were unique but not applicable for permanent metallic stents. When the Absorb scaffold and metallic stents are compared in the context of randomised trials, it is challenging to compare the two devices using the conventional methods. The primary purpose of this report is to explain the biases in conventional methodologies applied for metallic stents and for PLLA scaffolds at baseline and follow-up, and to propose a new standard methodology that enables us to compare two different devices using an almost identical and methodological language. Methods and results: A consensus amongst multiple core labs and expert researchers of OCT was reached on a new standard OCT measurement methodology that enables us to compare these two different devices. In brief, the proposed OCT methods are summarised as follows. 1) Both endoluminal and abluminal scaffold/stent contours should be traced. 2) Consistently, endoluminal and abluminal incomplete stent apposition areas should be measured. 3) The area occupied by scaffold/stent struts should be quantified directly or virtually. 4) The strut area should be systematically excluded from the flow area as well as the neointimal area. 5) Additional information on the degree of embedment could be reported using the interpolated lumen contour. Interobserver variability of the proposed method was excellent (intraclass correlation 0.89-100). Conclusions: A standardised OCT measurement methodology is proposed. This should be implemented in ongoing and future trials comparing the Absorb scaffolds and metallic stents.

Background: The edge vascular response (EVR) has been linked to important prognostic implications in patients treated with permanent metallic stents. We aimed to investigate the relationship of EVR with the geometric changes in the everolimus-eluting bioresorbable scaffold using serial optical coherence tomography (OCT) analysis. Methods and Results: In the first-in-man ABSORB trial, 28 patients (29 lesions) underwent serial OCT at 4 different time points (Cohort B1: post-procedure, 6, 24, and 60 months [n=13]; Cohort B2: post-procedure, 12, 36, and 60 months [n=15]) following implantation of the scaffold. In Cohort B1, there was no significant luminal change at the distal or proximal edge segment throughout the entire follow-up. In contrast, there was a significant reduction of the lumen flow area (LFA) of the scaffold between post-procedure and 6 months (−1.03±0.49 mm2 [P<0.001]), whereas between 6 and 60 months the LFA remained stable (+0.31±1.00 mm2 [P=0.293]). In Cohort B2, there was a significant luminal reduction of the proximal edge between post-procedure and 12 months (−0.57±0.74 mm2 [P=0.017]), whereas the lumen area remained stable (−0.26±1.22 mm2 [P=0.462]) between 12 and 60 months. The scaffold LFA showed a change similar to that observed in Cohort B1. Conclusions: Our study demonstrated a reduction in the scaffold luminal area in the absence of major EVR, suggesting that the physiological continuity of the lumen contour is restored long term.

__Background:__ The optimal implantation technique for the bioresorbable scaffold (Absorb, Abbott Vascular) is still a matter of debate. The purpose of the present study was to evaluate the effect of implantation technique on strut embedment and scaffold expansion. __Methods and Results:__ Strut embedment depth and scaffold expansion index assessed by optical coherence tomography (OCT) (minimum scaffold area/reference vessel area) were evaluated in the ABSORB Japan trial (OCT subgroup: 87 lesions) with respect to implantation technique using either quantitative coronary angiography (QCA) or OCT. Strut embedment was assessed at the strut level (n=667), while scaffold expansion was assessed at the lesion level (n=81). The mean embedment depth was 63±59 µm. Balloon sizing and inflation pressure had no direct effect on strut embedment. Plaque morphology affected strut embedment [nonatherosclerotic (58.9±54.3 µm), fibroatheroma (73.3±59.6 µm), fibrous plaque (59.7±51.1 µm), and fibrocalcific plaque (–3.1±61.6 µm, negative value means malapposition), P <0.001]. The balloon-artery ratio positively correlated with the expansion index. This relationship was stronger when the OCT-derived reference vessel diameter (RVD) was used as a reference for balloon selection rather than the QCA-derived one [predilatation (Pearson correlation r: QCA: 0.167 vs. OCT: 0.552), post-dilatation (QCA: 0.316 vs. OCT: 0.717)]. ___Conclusions:___ Underlying plaque morphology influenced strut embedment, whereas implantation technique had no direct effect on it. Optimal balloon sizing based on OCT-derived RVD might be recommended. However, the safety of such a strategy should be investigated in a prospective trial.

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 assess