Direct comparison of bioabsorbable and biodurable polymer everolimus-eluting stent in neointimal stent coverage and in-stent thrombus using high-resolution angioscope

Background/Introduction Although second-generation drug eluting stent (DES) employing biodurable polymer drastically shortened the duration of dual antiplatelet therapy (DAPT), previous reports raised concerns that switching from DAPT to single antiplatelet therapy increased rates of subsequent stent thrombosis with time. Third-generation DES employing bioabsorbable polymer has been introduced so as not to hinder the healing process of the vessel wall, however, at present, both DES with bioabsorbable polymer and those with biodurable polymer are used in parallel. It means there is no conclusive evidence regarding pros and cons of these two types of polymers. Purpose This study aims to clarify how bioabsorbable polymer and biodurable polymer act on the human coronary artery by observing neointimal stent coverage (NIC) and in-stent thrombus by comparing the third-generation DES with bioabsorbable-polymer cobalt-platinum everolimus-eluting stent (BP CoPt-EES), and the second-generation DES with biodurable-polymer cobalt-chromium everolimus-eluting stent (DP CoCr-EES). Methods This is a multicenter observational study including 11 hospitals. We investigated 70 stents (BP CoPt-EES: 40, DP CoCr-EES: 30) of 60 cases, who underwent stent implantation followed by simultaneous observation by coronary angiography, IVUS and angioscopy within 6 to 12 months. For angioscopy, we used a recently available, high-resolution angioscope with a pixel count of 9,000 which realized both stent coverage analysis and planar thrombus detection precisely. Neointimal stent coverage was graded from G0: non coverage to G3: full coverage, and heterogeneity value of neointima was measured as the difference between maximum and minimum NIC grade. Results A strong relationship was observed between NIC grade and in-stent thrombus in all stents (p=0.0011), and between the heterogeneity value and stent thrombus (p=0.012). There was no statistical difference in NIC grade between BP CoPt-EES vs. DP CoCr-EES; grade 0: 0 (0.0%) vs. 2 (6.7%), grade 1: 13 (32.5%) vs. 11 (36.7%), grade 2: 6 (15.0%) vs. 6 (20.0%), grade 3: 21 (52.5%) vs. 11 (36.7%), p=0.17) and neither in the heterogeneity value of neointima (p=0.49). The ratio of stent thrombus did not reach statistical difference; 16 (40.0%) in BP CoPt-EES vs. 17 (56.7%) in DP CoCr-EES (p=0.23). Conclusion The existence of stent thrombus was associated with the neointimal stent coverage. There was no significant difference both in neointimal stent coverage and stent thrombus between bioabsorbable polymer cobalt-platinum EES and biodurable polymer cobalt-chromium EES after 6 to 12 months following stent deployment. FUNDunding Acknowledgement Type of funding sources: Private company. Main funding source(s): Boston Scientific JapanOvalis ltd

Extended Stent Coverage Decreases Distal Aortic Segmental Enlargement After the Endovascular Repair of Acute Complicated Type B Aortic Dissection: A Multi-Center Retrospective Study of 814 Patients

Purpose: This study aimed to investigate the effect of distal aortic segmental enlargement (DASE) after thoracic endovascular aortic repair for complicated type B aortic dissection (cTBAD). Materials and Methods: From March 2003 to October 2018, 814 patients with acute cTBAD from 5 medical centers were retrospectively identified. DASE is indicated as the enlargement of distal aortic segmental volume ≥1.6 fold of the preoperative volume compared with the most recent postoperative computed tomography angiography (CTA) scan. Of these patients, 635 (78%) were identified as non-DASE, and 179 (22%) were identified as DASE. Competing risk analysis was performed to compare late death and distal aortic reintervention between the groups. The morphological variables and false lumen thrombosis at 7 aortic levels were measured based on the preoperative CTA and the most recent CTA. Univariate and multivariate Cox regression analyses were used to assess the independent predictors of DASE. Results: The mean follow-up time of the entire cohort was 5.6 years (interquartile range: 2.4–8.3 years). There were total of 208 late deaths, including 94 (14.8%) deaths in non-DASE group versus 114 (63.7%) deaths in the DASE group. Distal aortic reintervention was observed in 89 patients, with 43(6.7%) in the non-DASE group versus 46 (25.7%) in the DASE group. The cumulative incidence of late death and distal aortic reintervention were significantly higher in the DASE than in the non-DASE group (p<0.001). In morphological analysis, significant incomplete false lumen thrombosis was observed in all distal aortic segments above the aortic level of celiac artery (p<0.01). According to multivariate analysis, the Marfan syndrome, stent coverage to the level of diaphragm and the level of celiac artery were independent predictors of the DASE (p<0.001). Patients with extended stent coverage to the level of celiac artery have shown a lower incidence of DASE (p<0.010). Conclusion: Compared with the non-DASE group, patients with DASE demonstrated a higher rate of late death and distal aortic reintervention. For the cTBAD population, extended stent-graft coverage to the aortic section between diaphragm and celiac artery might serve as a “cost-efficient” cutoff point aiming to reduce the risk of DASE.

Delayed Proximal Flow Diverting Stent Migration in a Ruptured Intracranial Aneurysm: A Case Report

A flow diverter can be used to treat a ruptured aneurysm, especially during complicated cases for endovascular or open microsurgical procedures. However, some complications have been reported such as occlusion of side branches or perforating arteries, stent migration or improper stent position, re-rupture of the aneurysm, and in-stent thrombosis. A 38-year-old man diagnosed with a ruptured left supraclinoid aneurysm was treated with a Pipeline embolization device. Despite adequate stent coverage of the aneurysmal neck, delayed proximal migration was seen in follow-up imaging. To our knowledge, proximal migration of the stent mostly happens intraoperatively due to an undersized stent or excessive stretching. We report a case of delayed proximal flow diverter stent migration.

Angioscopic findings one year after percutaneous coronary intervention for chronic total occlusion

Background Chronic total occlusion (CTO) is thought as a high-risk feature of stent thrombosis, but little is known about the difference in neointimal healing of stents implanted for CTO lesions compared to that of non-CTO lesions. Methods and results A total of 62 stents in consecutive 47 patients (69±11 years, 41 male) who underwent follow-up angiography and angioscopy one year after percutaneous coronary intervention (PCI) between March 2016 and July 2019 were evaluated. The examined stents were divided into 3 groups according to the lesion status at previous PCI: CTO group (n=12), stable coronary artery disease without CTO (non-CTO group, n=30) and acute coronary syndrome (ACS group, n=20). The grade of neointimal stent coverage in CTO group was significantly lower than that of non-CTO group (0.5±0.5 vs 1.4±0.9, p=0.001). The frequency of presence of thrombus was significantly higher in CTO group and ACS group compared to non-CTO group (67%, 50%, and 13%, respectively, p=0.001). The yellow grade in CTO group was equivalent (p=1.00) to that in ACS group and was tented to be higher (p=0.051) compared to non-CTO group (1.3±0.8, 1.5±0.6, and 0.8±0.7, respectively). Conclusion The present study suggested a delayed healing in stents implanted for CTO lesions. Longer dual-antithrombotic therapy maybe beneficial for these patients. Funding Acknowledgement Type of funding source: None

P3393Comparison of intermediate-term vascular response to new-generation biodegradable polymer and durable polymer-based drug-eluting stents: optical coherence tomographic study

Background Over the last decade, drug-eluting stents (DES) have undergone substantial modifications with thinner struts and more biocompatible durable polymer (DP) or biodegradable polymer (BP). In DP-based DES, after drug elusion has been completed, DP remnants may trigger of local inflammatory vascular reactions and promote delayed healing, leading to accelerated neoatherosclerosis (NA). Thus, BPs have been developed to reduce the above-mentioned risks. Recently, poor strut coverage and in-stent NA are increasingly recognized the cause of late stent failure, but it is unclear whether BPs can reduce the incidence of NA and the poor stent coverage as compared to DPs. Objectives The purpose of this study was to compare the incidence of NA and the stent coverage using optical coherence tomography (OCT) between the DPs and the BPs. Methods Between July 2016 and April 2018, 127 consecutive patients with new-generation DES who underwent 8-month follow up OCT imaging were enrolled. Patients were divided into the two groups: DP group who had the new-generation durable polymer everolimus-eluting and zotarolimus-eluting stents and BP group who had the new-generation biodegradable polymer sirolimus-eluting and everolimus-eluting stents. We compared patient characteristics including hypertension, dyslipidemia and diabetes mellitus and 8-month follow up OCT findings including NA, uncovered struts and malapposed struts between the two groups. Results The DP group comprised 64 patients (50.4%. The incidence of NA, uncovered struts and malapposed struts were similar between the two groups (DPs vs BPs, 1.56% vs 7.94%, P=0.11; 7.80% vs 5.88%, P=0.16 and 2.76% vs 2.01%, P=0.43, respectively) (table). The other parameters were also similar between the two groups. Table 1 DP group (n=64) BP group (n=63) P value Hypertension 44 (68.8%) 50 (79.4%) 0.2251 Dyslipidemia 39 (60.9%) 37 (58.7%) 0.8573 Diabetes mellitus 25 (39.1%) 30 (47.6%) 0.3731 8 month OCT follow up findings Neoatherosclerosis 1 (1.6%) 5 (7.9%) 0.1147 Uncovered struts 7.8% (2.8–20.4) 5.9% (0.7–16.7) 0.1616 Malapposed struts 0.2% (0–2.8) 0% (0–2.8) 0.4392 Conclusions The new-generation DP based-DES may have similar effects on vascular response compared to the new-generation BP-based DES during 8-month follow-up period.

Left main stenting induced flow disturbances on ascending aorta and aortic arch

Background and Objective Ostial LM stenting potentially induces turbulence in the aortic wall near the LM ostium, which might be correlated with aorta dilation and dissection. We investigated through a computational fluid dynamic analysis (CFD), the presence and potential consequences of flow turbulences both in the ascending aorta and arch after a stenting left main (LM) mid shaft or distal disease. Methods The model of the ascending aorta and left coronary artery was reconstructed reviewing both angiographic and echocardiographic measurements of 80 consecutive patients (43 males, mean age 75.1 ± 6.2 years) with significant LM mid shaft or distal disease treated in our institution. For stent simulation, a third-generation everolimus-eluting stent was reconstructed. Two stenting procedures (lesion 1:1 or ostial coverage) were investigated. Results The net area averaged WSS of the model resulted higher when the stent covered the lesion 1:1 compared to the ostial coverage (3.68 vs. 2.06 Pa, P=0.01 and 3.97 vs. 1.98 Pa, P < 0.001, respectively). LM ostial coverage generates more turbulences in the LM itself, in the aortic wall at ostium level, and at the sino-tubular junction compared with the stenting of the lesion 1:1. Conversely, in the ascending aorta, the WSS appears lower when stenting the lesion 1:1. Conclusion Extending the stent coverage up to the ostium, when the ostial region is not diseased, might induce unfavorable alterations of flow; not only both at the level of the LM lesion and ostium sites, but also in the ascending aorta and aortic arch, potentially predisposing the aortic wall to long-term damage.