Impact of different stent alloys on human vascular response to everolimus-eluting stent: An optical coherence tomography study: The OCTEVEREST

Healing and stent coverage with the new ultrathin sirolimus-eluting stent with abluminal biodegradable polymer

BACKGROUND

Genoss drug-eluting stent (DES) (Genoss Company Limited) is a new ultrathin sirolimus-eluting stent with an abluminal biodegradable polymer and a cobalt-chromium platform.

AIMS

The aim of this study was to evaluate vascular healing and neointimal coverage after implantation of the Genoss DES using optical coherence tomography (OCT) 6 months postimplantation.

METHODS

From August 22, 2019 to June 17, 2020, this multicenter, observational, investigator-initiated study enrolled 20 patients who underwent OCT examination 6 months after Genoss DES implantation and provided informed consent. An analyst, blinded to the patients' and procedural information analyzed OCT images at an independent core laboratory.

RESULTS

Of the 20 patients, 19 with 27 stents in 21 lesions from 21 vessels were included in the analysis, while one patient withdrew consent and was unwilling to undergo follow-up OCT. OCT analysis was performed 204.4 ± 31.9 days after Genoss DES implantation. A total of 4285 stent struts from 661 cross-sections were analyzed. Strut tissue coverage was observed in 98.7 ± 4.3% of struts, with 0.1 ± 1.2% malapposed struts per lesion. The mean thickness of neointimal hyperplasia (NIH) on the covered struts was 0.12 ± 0.04 mm.

CONCLUSIONS

Six months after stent implantation, most Genoss DES struts were covered with a thin layer of NIH that was evenly distributed along the stent length. This pilot study evaluated the outcomes of 6 months dual antiplatelet therapy in the context of ultrathin strut stents, providing insight into developing ethical standards and a scientific foundation for conducting an adequately designed clinical trial.

The Outcome of Ultrathin-Strut Biodegradable Polymer-Coated Sirolimus-Eluting Stents in Coronary Artery Disease Patients - A Feasibility Study

Background

Drug-eluting coronary stents with ultrathin struts and biodegradable polymers have been shown to reduce inflammation, neointimal proliferation, and thrombus formation, leading to less early and late complications in patients with coronary artery disease as compared to thinner strut and durable polymer second-generation stents. In Oman, currently, second-generation stents are used for all patients.

Objective

The purpose of this feasibility study was to evaluate the clinical safety and performance of ultrathin-strut (60 μm) biodegradable polymer-coated sirolimus-eluting stents in an all-comers patient population.

Methods

This was a prospective, observational, single-center, and single-arm investigator-initiated study from August 2018 to August 2019. Inclusion criteria: 18 years of age, patients with symptomatic coronary artery disease indicated for percutaneous coronary intervention, and stenting of at least one coronary lesion. All patients were followed clinically or telephonically at 12 months after the index procedure.

Results

A total of 88 patients were recruited in the study, but 10 patients were lost to follow-up and hence excluded from the analysis. The overall mean age was 63 ± 13 years and 78% were males. The main comorbid conditions were hypertension (58%), diabetes mellitus (49%), and hyperlipidemia (26%). Fifty-three percent presented with unstable angina or non-ST elevation myocardial infarction (MI), 10% with ST elevation MI, recent MI 16%, 18% with stable angina, and 1.3% in cardiogenic shock. The mean left ventricular ejection fraction of the cohort was 46 ± 14%. Angiographically, Type A lesions were seen in 25%, Type B in 32%, and Type C in 42%. Left anterior descending stenting was done in 44%, right coronary artery in 32%, left circumflex artery in 14%, left main in 5%, and graft stenting in 4%. Device success was 96%. Procedural success was seen in 97% of patients. At 1-year follow-up, 93% were asymptomatic; overall device-oriented clinical events were 6.8% including cardiac death in 2.7%, target-vessel MI in 2.7%, and target-lesion revascularization in 1.3% which all occurred in uncontrolled diabetic patients.

Conclusions

At index admission and 1 year, ultrathin-strut biodegradable polymer-coated sirolimus-eluting stent study showed low device-related adverse clinical events which are comparable to published data for the second-generation stents. This feasibility study shows that these stents can be used in all types of stent-indicated patients with added advantages of biodegradable polymer and ultrathin struts. In addition, measures to prevent, diagnose, and control diabetes need to be taken in Oman as this cohort of patients develop ST after stenting.

Serial evaluation of vascular responses after implantation of everolimus-eluting coronary stent by optical coherence tomography

AIM

To evaluate healing response at strut-level and cross-section level after implanting an ultra-thin strut, everolimus-eluting stent with biodegradable polymer (Tetrilimus) using optical coherence tomography (OCT) at 3 and 6 months.

METHODS

This was prospective, multi-centre, single-arm, and investigator-initiated study performed at seven Indian sites between January, 2017 and September, 2018. OCT evaluations were performed in 57 patients who underwent Tetrilimus stent implantation. Follow-up OCT was scheduled at 3 months for first 16 patients and at 6 months for 41 patients. Primary outcomes included degree of strut coverage, malapposition and thickness of neointimal hyperplasia (NIH) over covered struts.

RESULTS

Sixty one Tetrilimus stents were implanted to treat 59 lesions in 57 patients. Paired (baseline and follow-up) OCT data was available for 12 patients and 30 patients at 3 and 6 months, respectively. At 3 months, rapid early healing was indicated by 95.48% covered struts per lesion with very low (0.11 ± 0.06 mm) NIH. At 6 months, NIH accumulation was greater (0.21 ± 0.07 mm) as compared to 3 months. 99.77% of struts per lesion were covered at 6 months. There was a very symmetrical healing as shown by very low eccentricity index. There was no difference in vascular healing between stents with small to moderate size vessels (≤3.00 mm) and large size vessels (>3.00 mm).

CONCLUSION

Present study demonstrated nearly complete endothelization and low NIH accumulation at 3 and 6 months following implantation of ultra-thin strut everolimus-eluting biodegradable polymer-coated Tetrilimus stent. Moreover, though being an ultra-thin strut stent, there was no difference in vascular healing and eccentricity after implantation of the Tetrilimus stents with smaller and larger diameters.

Comparison of Neointimal Response between Durable-Polymer Everolimus-Eluting Stent and Bioabsorbable-Polymer Everolimus-Eluting Stent for Severely Calcified Lesions Requiring Rotational Atherectomy

Clinical outcomes after percutaneous coronary intervention (PCI) for severely calcified lesions remain poor. The purpose of this study was to investigate the neointimal response after everolimus-eluting stents (EES) for severely calcified lesions treated with rotational atherectomy (RA) using optical coherence tomography (OCT).We retrospectively analyzed 34 lesions in which PCI was performed with EES deployment following RA and OCT was performed immediately after PCI and at follow-up (nine months). The EES was either durable-polymer (DP) EES (22 lesions) or bioabsorbable polymer (BP) -EES (12 lesions). Strut coverage and malapposition were evaluated at 1-mm intervals of cross-section (CS) by serial OCT analysis. Malapposed strut was defined as having the distance from luminal border > 100 μm.A total of 11,823 struts immediately after PCI and 11,720 struts at follow-up were analyzed. Immediately after PCI, the strut-level analysis showed no significant differences in the percentage of malapposed struts between the DP-EES group and the BP-EES group. At follow-up, the BP-EES group showed a more prevalent covered strut compared with the DP-EES group (strut-level analysis: 95% versus 97%, P = 0.045; CS-level analysis: 97% versus 100%, P < 0.01; lesion-level analysis: 27% versus 83%, P < 0.01, respectively).In severely calcified lesions requiring RA, the BP-EES group achieved better neointimal coverage than the DP-EES group at nine months. Additional prospective studies are needed.

Comparison of neointimal coverage between ultrathin biodegradable polymer-coated sirolimus-eluting stents and durable polymer-coated everolimus-eluting stents: 6 months optical coherence tomography follow-up from the TAXCO study

Aim

The TAXCO study was designed to compare the degree of neointimal coverage and the prevalence of malapposition at 6 months subsequent to implantation of ultrathin biodegradable polymer‐coated sirolimus‐eluting stents (SES) and durable polymer‐coated everolimus‐eluting stents (EES) of thin strut thickness using optical coherence tomography (OCT).

Methods

The TAXCO study included a total of 42 patients who gave consent and underwent OCT examination between August 2017 and September 2017. Of 42, five patients' OCT examinations were of insufficient quality for quantitative analysis. Thus, the OCT analysis group consisted of 37 patients. Among them, 16 patients were treated with Xience (Abbott Vascular) and 21 with Tetriflex (Sahajanand Medical Technologies Pvt. Ltd., Surat, India), 6 (±1) months earlier at our institution. The OCT was performed using a C7 Dragonfly™ imaging catheter (St. Jude Medical Inc.). All OCT images were analyzed at an independent core laboratory (Cardiovascular Research Center, São Paulo, Brazil) by analysts who were blinded to patient and procedural information.

Results

A total of 763 crosssections (6,882 struts) were analyzed in Xience group, and 1,127 crosssections (9,968 struts) in Tetriflex group. At 6 months, on per‐lesion basis, no significant differences were observed between Xience group and Tetriflex group in mean percentage of uncovered struts (1.87 ± 3.86 vs. 2.42 ± 3.46, p = .137) and malapposed struts (0.05 ± 0.2 vs. 0.21 ± 0.69, p = .302). Strut‐level neointimal thickness also did not differ between Xience group and Tetriflex group (0.18 ± 0.12 vs. 0.14 ± 0.08 mm, p = .286).

Conclusion

This OCT study found no significant difference in strut coverage and neointimal thickness at 6 months after implantation of biodegradable polymer‐coated Tetriflex, when compared with durable polymer‐coated Xience.

Prospective evaluation of an ultrathin strut biodegradable polymer-coated sirolimus-eluting stent: 12 months' results from the S-FLEX UK registry

OBJECTIVE

To prospectively evaluate safety and efficacy of the ultrathin strut biodegradable polymer-coated Supraflex sirolimus-eluting stent (S-SES) in 'real world' patient population requiring percutaneous coronary intervention (PCI).

METHODS

National, prospective, multicentre, single-arm, all-comers, observational registry of 469 patients treated with S-SES from July 2015 and November 2016 in 11 centres in UK. Primary endpoint was target lesion failure (TLF) at 12 months (cardiac death, target vessel myocardial infarction (MI) or clinically driven target lesion revascularisation (TLR)). Secondary endpoints included safety and performance outcomes at 12 months-overall stent thrombosis (ST), all-cause mortality, any MI, target vessel failure (TVF) and major adverse cardiac events (MACE-composite of cardiac death, MI, emergent or repeat revascularisation).

RESULTS

At 12 months, the primary endpoint occurred in 11 (2.4%) of 466 patients, consisting of 4 (0.9%) cardiac deaths, 3 (0.6%) target vessel MI and 7 (1.5%) TLR. Secondary endpoints findings included all-cause mortality in 6 (1.3%), TVF of 14 (3%), no definite ST, 1 (0.2%) probable ST and 3 (0.6%) possible ST. Overall MACE was observed in 18 (3.9%).

CONCLUSIONS

The S-FLEX UK registry showed that the S-SES is safe with a low incidence of TLF in routine clinical practise in patients with coronary artery disease being treated by PCI.

Safety and efficacy of a sirolimus-eluting coronary stent with ultra-thin strut for treatment of atherosclerotic lesions (TALENT): a prospective multicentre randomised controlled trial

BACKGROUND

Supraflex is a sirolimus-eluting stent with a biodegradable polymer coating and ultra-thin struts. We aimed to compare Supraflex with the standard of care, Xience, an everolimus-eluting stent with a durable polymer coating, regarding clinical outcomes with a randomised trial in an all-comer population.

METHODS

We did a prospective, randomised, single-blind, multicentre study (TALENT) across 23 centres in Europe (the Netherlands, Poland, the UK, Spain, Bulgaria, Hungary, and Italy). Eligible participants were aged 18 years or older, had one or more coronary artery stenosis of 50% or greater in a native coronary artery, saphenous venous graft, or arterial bypass conduit, and had a reference vessel diameter of 2·25-4·50 mm. Patients underwent percutaneous coronary intervention in an all-comer manner. We randomly assigned patients (1:1) to implantation of either a sirolimus-eluting stent with a biodegradable polymer coating and ultra-thin struts (Supraflex) or an everolimus-eluting stent with a durable polymer coating (Xience). Randomisation was done by local investigators by use of a web-based software with random blocks according to centre. The primary endpoint was a non-inferiority comparison of a device-oriented composite endpoint-cardiac death, target-vessel myocardial infarction, or clinically indicated target lesion revascularisation-between groups at 12 months after the procedure, assessed in an intention-to-treat population. On assumption of 1-year composite endpoint prevalence of 8·3%, a margin of 4·0% was defined for non-inferiority of the Supraflex group compared with the Xience group. This trial is registered with ClinicalTrials.gov, number NCT02870140.

FINDINGS

Between Oct 21, 2016, and July 3, 2017, 1435 patients with 1046 lesions were randomly assigned to Supraflex, of whom 720 received the index procedure, and 715 patients with 1030 lesions were assigned to Xience, all receiving the index procedure. At 12 months, the primary endpoint had occurred in 35 patients (4·9 %) in the Supraflex group and in 37 patients (5·3%) in the Xience group (absolute difference -0·3% [one-sided 95% upper confidence bound 1·6%], p_{non-inferiority}<0·0001). Definite or probable stent thrombosis prevalence, a safety indicator, was low in both groups and did not differ between them.

INTERPRETATION

The Supraflex stent was non-inferior to the Xience stent for a device-oriented composite clinical endpoint at 12 months in an all-comer population. Supraflex seems a safe and effective alternative drug-eluting stent to other stents in clinical practice.

FUNDING

European Cardiovascular Research Institute.

Serial Assessment of Strut Coverage of Biodegradable Polymer Drug-Eluting Stent at 1, 2, and 3 Months After Stent Implantation by Optical Frequency Domain Imaging: The DISCOVERY 1TO3 Study (Evaluation With OFDI of Strut Coverage of Terumo New Drug Eluting Stent With Biodegradable Polymer at 1, 2, and 3 Months)

BACKGROUND

To assess the vessel-healing pattern of Ultimaster drug-eluting stent using optical frequency domain imaging. Our hypothesis is that biodegradable polymer-based drug-eluting technology allows complete very early strut coverage.

METHODS AND RESULTS

The DISCOVERY 1TO3 study (Evaluation With OFDI of Strut Coverage of Terumo New Drug Eluting Stent With Biodegradable Polymer at 1, 2, and 3 Months) is a prospective, single-arm, multicenter study. A total of 60 patients with multivessel disease requiring staged procedure at 1 month were treated with Ultimaster. Optical frequency domain imaging was acquired at baseline, 1, 2, and 3 months. The primary end point is optical frequency domain imaging-assessed strut coverage at 3 months. Mean age of patients was 67.2±9.9 years, and 73.3% were male, and 36.7% presented with acute coronary syndrome. A total of 132 lesions were treated, with average 1.4 lesions per patient treated at baseline and 1.1 lesions treated at 1 month. Strut coverage at 3 months of single implanted stents (n=71, primary end point) was 95.2±5.2% and of combined single and overlapped stents was 95.4±4.9%. Strut coverage of combined single and overlapped stents at 1 (n=49) and 2 months (n=38) was 85.1±12.7% and 87.9±10.8%, respectively. The median neointimal hyperplasia thickness was 0.04, 0.05, and 0.06 mm, whereas mean neointimal hyperplasia obstruction was 4.5±2.4%, 5.2±3.4%, and 6.6±3.3% at 1, 2, and 3 months, respectively.

CONCLUSIONS

Nearly complete strut coverage was observed in this complex population very early after implantation of Ultimaster drug-eluting stent.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01844843.

A review in enormity of OCT and its enduring understanding of vulnerable plaque in coronary bifurcation lesion

Optical coherence tomography (OCT) has emerged as one of the most promising tools to assist the optimization of percutaneous coronary intervention (PCI). Its ability to provide unique information on the plaque at high risk for rupture, plaque composition, the thickness of the fibrous cap, the presence of macrophage and thrombi has not only assisted simple PCI but also in many complex bifurcation lesions PCI. OCT has helped to provide valuable anatomic information to optimize stent implantation and adapt PCI strategy in individual patients. This review article summarizes the current role of OCT as an imaging technology and prediction of vulnerable plaque, its site and composition at the coronary bifurcation lesions for supporting the clinical decision.

Impact of Diabetes Mellitus on Intravascular Ultrasound-Guided Provisional Stenting in Coronary Bifurcation Lesions J-REVERSE Sub-Study

OBJECTIVE

To investigate the impact of diabetes mellitus (DM) on provisional coronary bifurcation stenting under the complete guidance of intravascular-ultrasound (IVUS).

BACKGROUND

The efficacy of such intervention has not yet been fully elucidated in the DM patients.

METHODS

A total of 100 DM and 139 non-DM patients in a prospective multi-center registry of IVUS-guided bifurcation stenting were compared in angiographic results at 9 months. Vessel and luminal changes during the intervention were analyzed using the IVUS. Vascular healing at the follow-up was also investigated in 23 lesions in each group using optical coherence tomography (OCT).

RESULTS

No difference was detected regarding baseline reference vessel diameter and minimum lumen diameter in proximal main vessel (MV), distal MV, and side branch (SB). The rate of everolimus-eluting stent use (78.4% vs. 78.3%), final kissing inflation (60.1% vs. 49.0%), and conversion to 2-stent strategy (2.9% vs. 2.8%) were also similar. In the DM group, late loss was greater in proximal MV (DM 0.23 ± 0.29 vs. non-DM 0.16 ± 0.24 mm, P < 0.05) and SB (0.04 ± 0.49 vs. -0.08 ± 0.35 mm, P < 0.05). Smaller vessel area restricted stent expansion in the proximal MV (6.18 ± 1.67 vs. 6.72 ± 2.07 mm² , P < 0.05). More inhomogeneous neointimal coverage (unevenness score, 1.90 ± 0.33 vs. 1.72 ± 0.29, P < 0.05) and more frequent thrombus attachment (26% vs. 4%, P < 0.05) were documented in the proximal MV at 9-month follow-up OCT.

CONCLUSIONS

Despite IVUS optimization for coronary bifurcation, DM is potentially associated with smaller luminal gain, higher late-loss, and inhomogeneous vascular healing with frequent thrombus attachment in the proximal MV.

Clinical outcomes in 995 unselected real-world patients treated with an ultrathin biodegradable polymer-coated sirolimus-eluting stent: 12-month results from the FLEX Registry

OBJECTIVES

To evaluate, in the FLEX Registry, clinical outcomes of an ultrathin (60 µm) biodegradable polymer-coated Supraflex sirolimus-eluting stent (SES) for the treatment of coronary artery disease. Additionally, to determine the vascular response to the Supraflex SES through optical coherence tomography (OCT) analysis.

SETTING

Multicentre, single-arm, all-comers, observational registry of patients who were treated with the Supraflex SES, between July 2013 and May 2014, at nine different centres in India.

PARTICIPANTS

995 patients (1242 lesions) who were treated with the Supraflex SES, between July 2013 and May 2014, at nine different centres in India. A total of 47 participants underwent OCT analysis at 6 months' follow-up.

INTERVENTIONS

Percutaneous coronary intervention with Supraflex SES, PRIMARY AND SECONDARY OUTCOME MEASURES: The primary endpoint-the rate of major adverse cardiac events (defined as a composite of cardiac death, myocardial infarction (MI), target lesion revascularisation (TLR))-was analysed during 12 months.

RESULTS

At 12 months, the primary endpoint occurred in 36 (3.7%) of 980 patients, consisting of 18 (1.8%) cardiac deaths, 16 (1.6%) MI, 7 (0.7%) TLR and 2 (0.2%) cases of non-target lesion target vessel revascularization. In a subset of 47 patients, 1227 cross-sections (9309 struts) were analysed at 6 months by OCT. Overall, a high percentage of struts was covered (98.1%), with a mean neointimal thickness of 0.13 ± 0.06 µm.

CONCLUSIONS

The FLEX Registry evaluated clinical outcomes in real-world and more complex cohorts and thus provides evidence that the Supraflex SEX can be used safely and routinely in a broader percutaneous coronary intervention population. Also, the Supraflex SES showed high percentage of stent strut coverage and good stent apposition during OCT follow-up.

Randomized comparison of acute stent malapposition between platinum-chromium versus cobalt-chromium everolimus-eluting stents

No randomized data exist regarding optical coherence tomography (OCT) evaluation immediately post-procedure and at the 3-month follow-up for platinum-chromium everolimus-eluting stents (PtCr-EES) versus cobalt-chromium everolimus-eluting stents (CoCr-EES). A total of 100 patients were randomly assigned to undergo PtCr-EES (n = 51) or CoCr-EES (n = 49) implantation. OCT was serially evaluated after stent deployment with nominal pressure and immediately post-procedure, and 3-month follow-up. The primary endpoint was the percentage of malapposed strut after nominal pressure and immediately post-procedure. Compared to the CoCr-EES, the PtCr-EES showed a lower tendency of percent malapposed strut at nominal pressure [median value (interquartile range); 4.1 % (0.5-11.7) vs. 7.6 % (2.9-13.7), p = 0.082] and immediately post-procedure [1.2 % (0-3.4) vs. 2.5 % (0.7-5.3), p = 0.051]. The percentage of cross sections with any malapposed struts was significantly lower with PtCr-EES at nominal pressure [15.0 % (5.6-39.0) vs. 23.8 % (18.2-44.4), p = 0.036] and immediately post-procedure [6.5 % (0-15.3) vs. 10.5 % (7.1-20.0), p = 0.026]. At the 3-month follow-up, both PtCr-EES and CoCr-EES showed comparable percentages of malapposed struts (0 vs. 0 %, respectively, p = 0.332) and uncovered struts (5.3 vs. 4.7 %, respectively, p = 0.829). We found a significant correlation between the immediate post-procedural percentage of malapposed struts versus the percentage of uncovered struts (r = 0.430, p < 0.001) at the 3-month follow-up. Compared to the CoCr-EES, the PtCr-EES shows a lower tendency toward a lower percentage of malapposed struts but no significant difference in strut coverage at the 3-month follow-up. The percentage of malapposed struts immediately post-procedure was correlated with strut coverage at the 3-month follow-up.

The relationship between post-stent strut apposition and follow-up strut coverage assessed by a contour plot optical coherence tomography analysis

OBJECTIVES

This study sought to evaluate the relationship between post-stent strut apposition and follow-up strut coverage using contour plot optical coherence tomographic analysis.

BACKGROUND

Tracking the fate of interested regions of struts at different time points has not been investigated.

METHODS

Post-intervention and 6-month follow-up optical coherence tomographic evaluations were performed in 82 patients treated with biolimus- (n = 37) or sirolimus-eluting stents (n = 45). Post-stent apposition was classified as embedded, apposed, or malapposed. For volumetric stent evaluation, the post-intervention strut-artery distance and the neointimal thickness at follow-up were measured as a function of the circumferential arc length and longitudinal stent length. Computer-generated contour plots of the strut-artery distance and neointimal thickness were compared.

RESULTS

The percentages of embedded and malapposed struts after intervention were 1.8% (Interquartile range [IQR]: 0.6% to 6.2%) and 2.3% (IQR: 0.5% to 5.2%), respectively. The percentages of uncovered and malapposed struts at 6 months were 16.0% (IQR: 7.4% to 33.3%) and 0% (IQR: 0% to 0.7%), respectively. The percentage of uncovered struts at 6 months varied significantly with post-stent strut apposition (0% [IQR: 0% to 11.4%] in embedded, 16.3% [IQR: 8.1% to 31.3%] in apposed, and 26.8% [IQR: 0% to 56.3%] in malapposed, p < 0.001 for all pairwise comparisons). In lesions without tissue prolapse, embedded struts were all covered (100% covered struts) compared with those with tissue prolapse (76.8% covered, p < 0.001).

CONCLUSIONS

The optical coherence tomography-guided optimization of stent strut apposition enhances strut coverage at follow-up. This comprehensive method for evaluating strut apposition may provide more useful information to understanding the serial changes in strut coverage. (Neointimal Coverage After Implantation of Biolimus Eluting Stent With Biodegradable Polymer: Optical Coherence Tomographic Assessment According to the Treatment of Dyslipidemia and Hypertension and the Types of Implanted Drug-Eluting Stents; NCT01502904).

Mechanisms, pathophysiology, and clinical aspects of incomplete stent apposition

Incomplete stent apposition (ISA) is characterized by the lack of contact of at least 1 stent strut with the vessel wall in a segment not overlying a side branch; it is more commonly found in drug-eluting stents than bare-metal stents. The accurate diagnosis of ISA, initially only possible with intravascular ultrasound, can currently be performed with higher accuracy by optical coherence tomography, which also enables strut-level assessment due to its higher axial resolution. Different circumstances related both to the index procedure and to vascular healing might influence ISA occurrence. Although several histopathology and clinical studies linked ISA to stent thrombosis, potential selection bias precluded definitive conclusions. Initial studies usually performed single time point assessments comparing overall ISA percentage and magnitude in different groups (i.e., stent type), thus hampering a comprehensive understanding of its relationship with vascular healing. Serial intravascular imaging studies that evaluated vascular response heterogeneity recently helped fill this gap. Some particular clinical scenarios such as acute coronary syndromes, bifurcations, tapered vessels, overlapping stents, and chronic total occlusions might predispose to ISA. Interventional cardiologists should be committed to optimal stent choices and techniques of implantation and use intravascular imaging guidance when appropriate to aim at minimizing acute ISA. In addition, the active search for new stent platforms that could accommodate vessel remodeling over time (i.e., self-expandable stents) and for new polymers and/or eluting drugs that could induce less inflammation (hence, less positive remodeling) could ultimately reduce the occurrence of ISA and its potentially harmful consequences.

Review: the physiological and computational approaches for atherosclerosis treatment

The cardiovascular disease has long been an issue that causes severe loss in population, especially those conditions associated with arterial malfunction, being attributable to atherosclerosis and subsequent thrombotic formation. This article reviews the physiological mechanisms that underline the transition from plaque formation in atherosclerotic process to platelet aggregation and eventually thrombosis. The physiological and computational approaches, such as percutaneous coronary intervention and stent design modeling, to detect, evaluate and mitigate this malicious progression were also discussed.