Aims. Percutaneous coronary intervention with Y-stenting of coronary bifurcation disease is not commonly undertaken. The procedural and medium-term clinical outcomes of coronary bifurcation lesions treated with the proximal to distal Y stent technique by a single experienced operator were reviewed. Methods. A total of 167 consecutive procedures using either provisional Y strategies or full-coverage options performed at Auckland City Hospital, New Zealand, between January 2013 and July 2018 were included in this retrospective observational study. All medical records and coronary angiograms were reviewed.Results. Three-year clinical follow-up data were available in 162 of 167 patients. The primary endpoint, defined as the composite of cardiovascular death, spontaneous myocardial infarction (MI), target-lesion revascularization (TLR), target-vessel nontarget-lesion revascularization (nontarget-lesion TVR), and stent thrombosis (ST) occurred in 25 patients (15%) at 3 years. Secondary endpoints were all-cause mortality (12%), including cardiovascular mortality (6%), noncardiovascular mortality (4%), undetermined death (2%), spontaneous MI (7%), TLR (1%), nontarget-lesion TVR (0%), and ST (0.6%). Conclusions. The proximalto distal Y-stent technique is a widely applicable approach to bifurcation lesions, with good medium-term clinical outcomes when used in a heterogeneous group of clinical and anatomical scenarios. Complications related to the stented site were infrequent. Randomized, controlled trials are needed to assess its efficacy compared with other bifurcation interventional techniques.

To describe a novel technique for ostial stent placement using real‐time IVUS guidance.

Objectives In a coronary bifurcation bench model, to determine the effects of side branch (SB) wire crossing position and balloon position on the stent scaffolding after the final proximal optimization technique (POT). Background POT performed as a final step after SB dilatation or kissing balloon inflation (KBI) has been widely advocated despite limited evidence. Methods Thirty-one stent implantations in bifurcation phantoms were performed using a one-stent provisional technique with (KBI) (n= 13), with POT-side-POT technique (n= 12) or with the two-stent culotte technique (n= 6). SB wiring was performed through either a proximal or a distal stent cell and confirmed by optical coherence tomography. Final POT was performed with the balloon positioned either across or proximal to the SB takeoff. The area of the opened stent cell in front of the SB was assessed by 3D reconstructed microcomputation tomography scans performed before and after Final POT. Results In cases with metallic carina, final POT across the SB takeoff caused SB rejailing. Regardless of stent technique and wire position, a Final POT across the SB takeoff reduced the SB cell opening area by 43% [32%;58%] (n= 15). The largest reduction (54-70%) was found after the POT-side-POT technique in procedures with a proximal wiring. Final POT performed proximal to the SB takeoff caused limited or no SB cell opening area reduction (4% [0.6%;6%] [n= 16]). Conclusion Final POT with balloon positioned across the SB takeoff in a narrow angle bifurcation reduces largest stent cell area in front of the SB ostium and may cause SB rejailing in cases with metallic carina.

Proximal to distal Y stenting technique is a modified bifurcation technique based on the original Y stenting technique described over 20 years ago. We use a bench top model to illustrate the steps of the technique, which can provide both provisional and full coverage options, using radial artery access. This technique may be applied in clinical settings on a wide range of bifurcation anatomies with a number of unique advantages.

Objectives To compare on the bench the physical and mechanical properties of Magmaris, a magnesium bioresorbable scaffold (BRS), with Absorb and DESolve polymeric BRS and a permanent metallic stent. Background Understanding the mechanical and physical properties of BRS is crucial for appropriate implantation and postdilatation. Methods Testing was performed in fluid at 37 degrees C and in silicone bifurcation phantoms with a 30 degrees angle between main branch (MB) and side branch. Results The 3.0-mm Magmaris BRS did not fracture after MB postdilatation up to 4.4 mm in contrast to the Absorb where the safe postdilatation diameter was 3.7 mm. For dilatation through stent cells, there were no Magmaris fractures with 3.0-mm noncompliant (NC) balloons inflated to nominal pressure. Mini-kissing balloon postdilatation with two 3.0-mm NC balloons up to 17 atm was without fracture except for an outlier. Longitudinal and radial strengths were similar for Magmaris and Absorb BRS. The crossing profile for the Magmaris was larger than other devices. Recoil 120 min after deployment was the greatest for Magmaris but 120 min after 3.5 mm postdilatation all devices had similar diameters. Conclusions The Magmaris BRS was more resistant to strut fracture than Absorb. It had a larger crossing profile than other devices and similar radial and longitudinal strengths to Absorb. While recoil after deployment was greater with Magmaris, 120 min after 3.5 mm postdilatation all devices had similar diameters.

Introduction Bioresorbable scaffolds (BRS) were designed as an alternative to metallic stents with the goal of complete resorption to allow vascular remodelling and to decrease late clinical events associated with permanent implants1. The DESolve® scaffold (Elixir Medical Corporation, Milpitas, CA, USA) is a next-generation scaffold with an early biodegradation and bioresorption profile that has demonstrated positive vascular remodelling at six months and favourable clinical outcomes2,3. The device is comprised of poly-L-lactic acid (PLLA) coated with a matrix of novolimus and a polylactide-based polymer. The strut thickness is 150 µm. We report the five-year clinical results with 18...

We investigated if blood flow changes induced through the presence of a stent could be detected using in vitro dynamically scaled 4D Phase-Contrast Magnetic Resonance Imaging (PC-MRI). Using idealized and patient-specific left main coronary artery bifurcations, we 3D-printed the dynamically large scaled geometries and incorporated them into a flow circuit for non-invasive acquisition with a higher effective spatial resolution. We tested the effects of using non-Newtonian and Newtonian fluids for the experiment. We also numerically simulated the same geometries in true scale for comparison using computational fluid dynamics (CFD). We found that the experimental setup increased the effective spatial resolution enough to reveal stent induced blood flow changes close to the vessel wall. Non-Newtonian fluid replicated all of the flow field well with a strong agreement with the computed flow field (R2 > 0.9). Fine flow structures were not as prominent for the Newtonian compared to non-Newtonian fluid consideration. In the patient-specific geometry, arterial non-planarity increased the difficulty to capture the near wall slow velocity changes. Findings demonstrate the potential to dynamically scale in vitro 4D MRI flow acquisition for micro blood flow considerations.

Background: Spontaneous coronary artery dissection (SCAD) is an uncommon but under-recognised cause of acute coronary syndromes, most often affecting younger women. Methods: Over the last 24 years, all patients from Auckland and Northland undergoing angiography and diagnosed with SCAD were entered into a prospective registry. Patient demographic, clinical and angiographic data were collated. Follow-up coronary angiography was undertaken in a subset. Results: Between 1994 and 2018, 155 patients experienced 166 events of SCAD. The mean age at index presentation was 49.4 ± 11.1 years and 119 (76%) were female. Atherosclerotic risk factors included overweight or obesity (44%), hypertension (28%), dyslipidaemia (24%), family history of premature ischaemic heart disease (20%), and current smoking (16%). Forty-one (27%) presented with ST-elevation myocardial infarction (STEMI) while 96 (62%) presented with non-STEMI. The left anterior descending artery was the most frequently affected artery (47%). Treatment was conservative in the majority, but 19 patients underwent coronary artery stenting and four patients had coronary artery bypass grafting. All but two patients survived the index hospital admission. Thirty-nine patients (25%) had subsequent coronary imaging, 3.28 ± 3.18 years later; the majority of coronary dissections had healed. At latest follow-up, 10 patients had suffered from recurrent dissection and 11 had died. At 5 and 10 years, Kaplan-Meier survival was 96.1% and 94.2% respectively, and survival free of dissection 92.3% and 89.0%, respectively. Conclusion: SCAD should be considered in all patients, particularly younger females, presenting with an acute coronary syndrome. The long-term clinical and angiographic prognosis is generally favourable.

OBJECTIVES:To confirm clinically that coronary balloon catheter tips may be damaged during bifurcation treatment with side-branch access through the side of a stent. On the bench, we aimed to assess the susceptibility of different balloon designs to damage. We compared catheter tip widths. We tested whether balloon tip flaring can cause stent distortion.BACKGROUND:We had observed that balloon catheters that failed to cross to a side-branch frequently exhibited tip damage.METHODS AND RESULTS:We examined microscopically for damage 82 balloon tips after clinical side-branch access. In a bench study, the forces required to compress catheter tips 0.5 mm were compared to assess susceptibility to damage. We compared tip widths of balloons of different nominal inflation diameters. We examined stents after side-branch access for distortion. In 42 of 48 (88%) of balloon tips from patients with resistance to or failure to cross through the side of a stent there was tip damage. Even when the balloon crossed without perceptible resistance, tip damage occurred in over half of balloons 18/34 (53%). Some balloon designs were more resistant to damage than others. Tips from balloons of different nominal diameters from the same manufacturer had the same width. Stent distortion caused by damaged balloon tips is improved by kissing balloon post-dilatation.CONCLUSIONS:Balloon tip damage is common with crossing between stent struts. This is one cause of failure of a balloon to access a side-branch and a new balloon should be used. If stent distortion is suspected, it should be corrected with kissing balloon post-dilatation.

Aims: This study sought to investigate the long-term clinical outcomes related to scaffold sizing based on quantitative coronary angiography. Methods and results: A total of 1,248 patients who received Absorb bioresorbable scaffolds in the ABSORB Cohort B, ABSORB EXTEND, and ABSORB II trials were included in the analysis. The incidence of MACE (a composite of cardiac death, any myocardial infarction [MI], and ischaemia-driven target lesion revascularisation [ID-TLR]) was analysed according to the Dmax subclassification of oversized scaffold group versus non-oversized (any undersize) scaffold group. At three years, event rates were similar in both groups in MACE (9.4% vs. 9.8%, p=0.847), target vessel MI (5.2% vs. 4.8%, p=0.795), and ID-TLR (4.8% vs. 5.8%, p=0.445). Landmark analysis after one year showed that the non-oversized scaffold group had higher rates of MACE (3.2% vs. 6.9%, log-rank p=0.004), target vessel MI (0.7% vs. 2.7%, log-rank p=0.007), and ID-TLR (2.5% vs. 4.7%, log-rank p=0.041). Conclusions: Implantation of an undersized scaffold was associated with a higher risk of MACE between one and three years, while in the previous report an oversized scaffold was associated with a higher risk of MACE up to one year. This implies different mechanisms for early and late events after scaffold implantation.

This is a consensus document from the European Bifurcation Club concerning bench testing in coronary artery bifurcations. It is intended to provide guidelines for bench assessment of stents and other strategies in coronary bifurcation treatment where the United States Food and Drug Administration (FDA) or International Organization for Standardization (ISO) guidelines are limited or absent. These recommendations provide guidelines rather than a step-by-step manual. We provide data on the anatomy of bifurcations and elastic response of coronary arteries to aid model construction. We discuss testing apparatus, bench testing endpoints and bifurcation nomenclature.

Background:Percutaneous coronary intervention in complex bifurcation lesions is prone to suboptimal implantation results and is associated with increased risk of subsequent clinical events. Angiographic ambiguity is high during bifurcation stenting, but it is unknown if procedural guidance by intravascular optical coherence tomography (OCT) improves clinical outcome. Methods and Design:OCTOBER is a randomized, investigator-initiated, multicenter trial aimed to show superiority of OCT-guided stent implantation compared to standard angiographic-guided implantation in bifurcation lesions. The primary outcome measure is a 2-year composite end point of cardiac death, target lesion myocardial infarction, and ischemia-driven target lesion revascularization. The calculated sample size is 1,200 patients in total, and allocation is 1:1. Eligible patients have stable or unstable angina pectoris or stabilized non–ST elevation myocardial infarction, and a coronary bifurcation lesion with significant main vessel stenosis and more than 50 % stenosis in a side branch with a reference diameter ≥2.5mm. Treatment is performed by the provisional side branch stenting technique or 2-stent techniques, and the systematic OCT guiding protocol is aimed to evaluate (1) plaque preparation, (2) lesion length, (3) segmental reference sizes, (4) lesion coverage, (5) stent expansion, (6) malapposition, (7) wire positions, and (8) ostial results. Implications:A positive outcome of the OCTOBER trial may establish OCT as a routine tool for optimization of complex percutaneous coronary intervention, whereas a negative result would indicate that OCT remains a tool for ad hoc evaluation in selected cases.

AIMS:The aim of this study was to evaluate the five-year clinical results of a sirolimus-eluting stent (MiStent SES) with a bioabsorbable coating designed for sustained drug delivery during and after rapid polymer dissolution.METHODS AND RESULTS:The five-year results from the DESSOLVE I and II trials including major adverse cardiac events (MACE), target lesion failure (TLF), target vessel failure (TVF), and stent thrombosis (ST) at five-year follow-up are reported. In DESSOLVE I, 10.3% of patients receiving the MiStent SES (3/29) had a MACE event up to five years without TLF. In DESSOLVE II, 15.1% of patients in the MiStent group (18/119) had a five-year MACE event compared to 22.0% of patients in the Endeavor group (p=0.295). TLF was 9.2% in the MiStent group and 8.5% in the Endeavor group (p=1.00). TVF was 10.1% for MiStent versus 15.3% for Endeavor (p=0.331). Up to five-year follow-up, the MiStent SES has continued to demonstrate low rates of TLR across DESSOLVE I (0.0%) and DESSOLVE II (3.4%). No ST was reported with the MiStent up to five years in the DESSOLVE I trial. In DESSOLVE II, definite or probable ST was 0.0% with MiStent and 1.7% with Endeavor up to five years.CONCLUSIONS:The MiStent SES demonstrated long-term safety and effectiveness with low rates of five-year MACE, TLF, and TVF across these two clinical trials.

In the article by Onuma et al (Onuma Y, Grundeken MJ, Nakatani S, Asano T, Sotomi Y, Foin N, Ng J, Okamura T, Wykrzykowska JJ, de Winter RJ, van Geuns RJ, Koolen J, Christiansen E, Whitbourn R, McClean D, Smits P, Windecker S, Ormiston JA, Serruys PW. Serial 5-year evaluation of side branches jailed by bioresorbable vascular scaffolds using 3-dimensional optical coherence tomography: insights from the ABSORB Cohort B trial (A Clinical Evaluation of the Bioabsorbable Everolimus Eluting Coronary Stent System in the Treatment of Patients With De Novo Native Coronary Artery Lesions). Circ Cardiovasc Interv. 2017;10:9:e004393. DOI: 10.1161/CIRCINTERVENTIONS. 116.004393.), which published online September 11, 2017, and appeared in the September 2017 issue of the journal, a correction was needed. Dr Christiansen's name should appear as Evald H. Christiansen. This correction has been made to the article, which is available at http://circinterventions. ahajournals.org/content/10/9/e004393.

s for the Cardiac Society of Australia and New Zealand Annual Scientific Meeting (New Zealand) 2018, 14 – 16 June 2018, Christchurch, New Zealand Oral Presentations Young Investigator Award Abstracts

Aims: The aim of the study was to investigate long-term changes in lumen eccentricity and asymmetry at five years after implantation of the Absorb bioresorbable vascular scaffold (BVS). Methods and results: Out of 101 patients from the ABSORB cohort B trial, 28 patients (29 lesions) with serial optical coherence tomography (OCT) examination at four different time points (cohort B1: postprocedure, six months, two, and five years [n=13]; cohort B2: post-procedure, one, three, and five years [n=16]) were evaluated. The longitudinal variance in lumen diameter was assessed by asymmetry index (AI). An asymmetric lesion was defined as AI u003e0.3. The circularity of the lumen or scaffold was evaluated by the eccentricity index calculated as minimal divided by maximal luminal or scaffold diameter per cross-section. The lowest lumen eccentricity index within a scaffold segment (EIL) u003c0.7 was defined as an eccentric lesion. Post procedure, an eccentric lesion was observed in 72.4% and became concentric in 93.1% at five years (post EIL 0.67±0.05 vs. five-year EIL 0.80±0.10, p=0.03) with a modest reduction of the lumen area from baseline to five years by 0.75±0.32 mm2. Asymmetric lumen morphology was observed in 93.1% (n=27) post implantation and persisted until five-year follow-up. On serial OCT analyses, there was a substantial increase in the scaffold EI during the first two years (post 0.70±0.06, six months 0.76±0.08, two years 0.85±0.07); then, it remained stable whereas the lumen circularity improved further. There were no significant differences in major adverse cardiac events regarding the lumen morphology over the fiveyear follow-up. Conclusions: In patients treated with the Absorb BVS, the cross-sectional circularity improved over five years while the variance in longitudinal diameters remained. Regaining of lumen circularity is mainly caused by reshaping of the scaffold during the first two years.

The ideal stent must fulfil a broad range of technical requirements. Stents must be securely crimped onto the delivery balloon and, in this form, must have a low profile and be sufficiently flexible to facilitate deliverability to the lesion site without distortion or displacement. Following expansion, stents must exert sufficient radial force on the vessel wall to overcome lesion resistance and elastic recoil. To achieve an optimal lumen diameter, the lesion must be uniformly and adequately scaffolded, with minimal tissue prolapse between struts but without compromising side-branch access. Furthermore, the deployed stent must conform to the vessel curvature to minimise vessel distortion, particularly at the stent edges. Radio-opacity is also important to guide safe positioning, adequate deployment and postdilataion and to permit assessment of optimal stent expansion. Equally though, the stent lumen must also be sufficiently visible to allow radiographic assessment of flow dynamics and restenosis. Efforts to optimise one characteristic of stent design may have detrimental effects on another. Thus, currently available stents all reflect a compromise between competing desirable features and have subtle differences in their performance characteristics. Striving to achieve stents with optimal deliverability, conformability and radial strength led to a reduction in longitudinal strength. The importance of this parameter was highlighted by complications occurring in the real-world setting where percutaneous coronary intervention is often undertaken in challenging anatomy. This review focuses on aspects of stent design relevant to longitudinal strength.