Incidence and Clinical Outcomes of Stent Fractures on the Basis of 6,555 Patients and 16,482 Drug-Eluting Stents From 4 Centers

In-stent restenosis caused by a reprotruding calcified nodule and stent fracture in the hinged coronary artery

Calcified nodules (CNs) cause in-stent restenosis (ISR) frequently. Although reprotrusion of CNs through stent struts is one of the mechanisms of ISR, the process of this phenomenon has not been understood. Furthermore, little is known about stent fracture (SF) occurring at the site of CNs. We are presenting a case of an 82-year-old male who developed early ISR due to the combination of an in-stent CN and SF in the hinged right coronary artery. The process of progression of the in-stent CN was recorded sequentially with angiography and intravascular ultrasound (IVUS). IVUS from the fulcrum of hinge motion revealed the repetitive protruding movement of the CN into the stent lumen.

Asymptomatic Complete Spiral Stent Fracture in Subclavian Artery with Progressive Restenosis in the Early Postoperative Period: A Case Report

Objective

Stent fractures may be a risk factor for delayed restenosis, but it is difficult to diagnose asymptomatic stent fractures in the subclavian artery (SCA). We report a rare case of percutaneous transluminal angioplasty and stenting (PTAS) for SCA stenosis with asymptomatic severe stent fracture that showed progressive in-stent stenosis in the early postoperative period.

Case Presentation

A 70-year-old woman presented with left arm claudication. Magnetic resonance imaging at the time of admission showed SCA stenosis with severe calcification. Because of the left subclavian steal phenomenon on ultrasonography of the left vertebral artery, she underwent PTAS using a balloon-expandable stainless stent. Ultrasonography the day after treatment showed appropriate stent placement. Computed tomography angiography (CTA) 30 days after PTAS showed an asymptomatic complete spiral stent fracture at the mid-portion of the stent. The in-stent stenosis then gradually progressed on follow-up ultrasonography at the site of the stent fracture. Nine months after the first PTAS, a second PTAS using a self-expandable nitinol stent was performed because the peak systolic velocity exceeded 300 cm/s on Doppler ultrasound. Two years after the second PTAS, no neurological symptoms and no stent deformation were observed.

Conclusion

PTAS with a balloon-expandable stainless stent for SCA stenosis with severe calcification may lead to stent fracture. In the case of severe stent fracture, careful follow-up may be needed for the detection of asymptomatic in-stent stenosis in the early postoperative period.

Fracture and plastering of distal left main stent during double-kissing Culotte technique: a case report

Background

Acute fracture of a left main (LM) stent during angioplasty is a rare complication. Cardiologists should be aware of the risk of stent fracture (SF) following kissing balloon inflation (KBI) even if the effective diameter of the balloons does not exceed the recommended expansion limits of stents.

Case summary

A 64-year-old female with hypertension and dyslipidaemia presented with crescendo angina since three months in spite of optimal medical therapy. Coronary angiogram showed a distal LM bifurcation lesion. The patient was admitted for LM bifurcation stenting by upfront two-stent technique (inverted double-kissing Culotte technique). Following first KBI of the stent placed from left circumflex artery (LCX) to LM, there was stent deformation in the LM shaft. As we had planned the Culotte technique, we decided to exclude the fractured segment by stenting from left anterior descending artery (LAD) to LM. The stent from LAD-LM successfully excluded the fractured part of the first stent from the lumen of LM. Optical coherence tomography done after final KBI from LCX-LM revealed successful exclusion of the deformed segment of the LCX stent with mild malapposition at the site of the deformed stent. A follow-up angiogram after six months showed normal in-stent flow with no evidence of restenosis or pseudoaneurysm.

Discussion

Acute LM SF during coronary intervention can occur even if the effective cumulative diameter of the inflated balloons does not exceed the mentioned expansion limit of stents. Intravascular imaging is a helpful modality to define type of SF and its management.

The Role of CT Imaging in a Fractured Coronary Stent with Pseudoaneurysm Formation

We report a case of a 63-year-old male patient with multiple cardiovascular risk factors and previous myocardial infarction who was referred to the emergency department on September 2023 with symptoms and clinical and biological data consistent with an acute coronary event. A coronary angiography revealed severe ostial stenosis of the left anterior descending artery (LAD) and intrastent thrombotic occlusion in the first two segments of the LAD. Two drug-eluting stents were implanted and the patient was discharged when hemodynamically stable; however, three weeks later, he returned to the emergency department complaining of fever, anterior chest pain, dyspnea at rest, and high blood pressure values at home. High levels of troponin T, C-reactive protein, and NT-proBNP were detected and blood cultures showed methicillin-resistant Staphylococcus aureus. The computed tomography (CT) examination showed a saccular dilatation had developed between two fragments of a stent mounted at the level of the LAD, surrounded by a hematic pericardial accumulation. LAD pseudoaneurysm ablation and a double aortocoronary bypass with inverted saphenous vein autograft were performed and the patient showed a favorable postoperative evolution. In this case, surgical revascularization was proven to be the appropriate treatment strategy, demonstrating the need to choose an individualized therapeutic option depending on case-specific factors.

Ostial right coronary artery lesion morphology and outcomes after treatment with drug-eluting stents

BACKGROUND

Outcomes after percutaneous coronary intervention (PCI) for de novo ostial right coronary artery (RCA) lesions are poor.

AIMS

We used intravascular ultrasound (IVUS) to clarify the morphological patterns of de novo ostial RCA lesions and their associated clinical outcome.

METHODS

Among 5,102 RCA IVUS studies, 170 de novo ostial RCA stenoses (within 3 mm from the aorto-ostium) were identified. These were classified as 1) isolated ostial lesions (no disease extending beyond 10 mm from the ostium and without a calcified nodule [CN]); 2) ostial CN, typically with diffuse disease (disease extending beyond 10 mm); and 3) ostial lesions with diffuse disease but without a CN. The primary outcome was target lesion failure (TLF: cardiac death, target vessel myocardial infarction, definite stent thrombosis, and ischaemia-driven target lesion revascularisation).

RESULTS

The prevalence of an isolated ostial lesion was 11.8% (n=20), 47.6% (n=81) were ostial CN, and 40.6% (n=69) were ostial lesions with diffuse disease. Compared to ostial lesions with diffuse disease, isolated lesions were more common in women (75.0% vs 42.0%; p=0.01), and CN were associated with older age (median [first, third quartile] 76 [70, 83] vs 69 [63, 81] years old; p=0.002). The Kaplan-Meier rate of TLF at 2 years was significantly higher in patients with CN (21.6%) compared to diffuse lesions (8.2%) (p=0.04), and patients with isolated lesions had no events. A multivariable Cox proportional hazard model revealed that CN were significantly associated with TLF (hazard ratio 6.63, 95% confidence interval: 1.28-34.3; p=0.02).

CONCLUSIONS

Ostial RCA lesions have specific morphologies - detectable by IVUS - that may be associated with long-term clinical outcomes.

The role of optical coherence tomography in guiding percutaneous coronary interventions: is left main the final challenge?

Left main (LM) coronary artery disease is a high-risk lesion subset, with important prognostic implications for the patients. Recent advances in the field of interventional cardiology have narrowed the gap between surgical and percutaneous approach of this complex lesion setting. However, the rate of repeat revascularization remains higher in the case of percutaneous coronary intervention (PCI) on long-term follow-up. As such, the need for better stent optimization strategies has led to the development of intravascular imaging techniques, represented mainly by intravascular ultrasound (IVUS) and optical coherence tomography (OCT). These techniques are both able to provide excellent pre- and post-PCI guidance. While IVUS is an established modality in optimizing LM PCI, and is recommended by international revascularization guidelines, data and experience on the use of OCT are still limited. This review paper deeply analyzes the current role of OCT imaging in the setting of LM disease, particularly focusing on its utility in assessing plaque morphology and distribution, vessel dimensions and proper stent sizing, analyzing mechanisms of stent failure such as malapposition and underexpansion, guiding bifurcation stenting, as well as offering a direct comparison with IVUS in this critical clinical scenario, based on the most recent available data.

Double-wire woven nitinol stent for treating dogs with refractory tracheal collapse: A case series

This retrospective case series describes the signalments, clinical signs, diagnostic test results, and postoperative complications obtained from the medical records of 10 client-owned dogs that underwent treatment for grade IV tracheal collapse using double-wire woven nitinol stents between October 2017 and September 2021. Respiratory signs resolved in all dogs immediately after tracheal stent placement. Mild to moderate stent fractures were identified in five dogs, of which two showed concurrent respiratory distress necessitating re-stenting after several months. Minor complications, such as stent migration, were absent. The double-wire woven nitinol stent optimised for the canine trachea showed favourable outcomes and minimal complications.

Impact of inverse unequal height strut structure on the functional performance of an additively manufactured cardiovascular stent

Recently, additive manufacturing (AM) has been investigated as an innovative method to manufacture stents due to its capability in producing complex and customized structures. In this paper, the cardiovascular stents of M-type and N-type with inverse unequal height strut structure and N-type with equal height strut structure were designed and manufactured by Selective Laser Melting (SLM). Following surface polishing, balloon expansion, plane compression and three-point bending experiments were carried out to evaluate the mechanical performance of the stent. The stents designed with inverse unequal height strut structure showed higher radial support performance and lower radial recoil when compared to the stents with uniform design. This study proved the feasibility of SLM in rapid manufacturing of cardiovascular stents that can be used for performance evaluation in design stage.

Mechanisms and treatment outcomes of ostial right coronary artery in-stent restenosis

BACKGROUND

Despite a high rate of in-stent restenosis (ISR) after stenting the right coronary artery (RCA) ostium, the mechanism of ostial RCA ISR is not well understood.

AIMS

We aimed to clarify the cause of ostial RCA ISR using intravascular ultrasound (IVUS).

METHODS

Overall, 139 ostial RCA ISR lesions were identified with IVUS, pre-revascularisation. Primary ISR mechanisms were classified as follows: 1) neointimal hyperplasia (NIH); 2) neoatherosclerosis; 3) ostium not covered by the stent; 4) stent fracture or deformation; 5) stent underexpansion (old minimum stent area <4.0 mm2 or stent expansion <50%); or 6) a protruding calcified nodule.

RESULTS

The median duration from prior stenting was 1.2 (first quartile 0.6, third quartile 3.1) years. The primary mechanisms of ISR were NIH in 25% (n=35) of lesions, neoatherosclerosis in 22% (n=30), uncovered ostium in 6% (n=9) (biological cause 53%, n=74), stent fracture or deformation in 25% (n=35), underexpansion in 11% (n=15), and protruding calcified nodules in 11% (n=15) (mechanical cause 47%, n=65). Including secondary mechanisms, 51% (n=71) of ostial RCA ISRs had stent fractures that were associated with greater hinge motion of the ostial-aorta angle during the cardiac cycle. The Kaplan-Meier rate of target lesion failure at 1 year was 11.5%. When the mechanically caused ISRs were treated without new stents, they suffered a higher subsequent event rate (41.4%) compared with non-mechanical causes or mechanical causes treated without restenting (7.8%, unadjusted hazard ratio 6.44, 95% confidence interval: 2.33-17.78; p<0.0001).

CONCLUSIONS

Half of the ostial RCA ISRs were due to mechanical causes. Subsequent event rates were high, especially in mechanically caused ISRs treated without the implantation of a new stent.

Impact of the ultra-long 48 mm drug-eluting stent on procedural and clinical outcomes in patients with diffuse long coronary artery disease

BACKGROUND

Diffuse coronary artery disease (CAD) is a prognostic factor after percutaneous coronary intervention (PCI) and requires multiple overlapping stent implantations.

HYPOTHESIS

We investigated the impact of ultra-long 48 mm drug-eluting stent (DES) on procedural and clinical outcomes in real-world practice.

METHODS

Patients who underwent DES implantation for a lesion length of >40 mm were selected from a prospective registry between 2019 and 2021. Patients treated with one or more ultra-long 48 mm DES were in the ultra-long DES group (n = 221). The others comprised the conventional DES group (n = 428). Procedural and clinical outcomes were compared after propensity score matching (PSM). The primary endpoint was a device-oriented composite outcome (DOCO) consisting of cardiac death, target vessel-related myocardial infarction, and target lesion revascularization at 1-year follow-up.

RESULTS

After PSM, 158 matched pairs of patients showed no differences in the baseline clinical and angiographic characteristics. The stent delivery failure rate, the use of guide-extension catheter or anchor balloon technique, and the procedural success rate were similar for both groups. Approximately two-thirds of lesions could be treated with one DES in the ultra-long DES group. At 1-year follow-up, the DOCO was similar for both groups (2.5% vs. 0.6%, p = .168).

CONCLUSIONS

In daily clinical practice, ultra-long DES implantation is as safe and effective as multiple overlapping conventional DES implants in treating diffuse long CAD. However, ultra-long DES can reduce the number of stents. (Trial Registration: ClinicalTrials.gov Identifier: NCT02038127).

Stent Thrombosis and Restenosis with Contemporary Drug-Eluting Stents: Predictors and Current Evidence

Iterations in stent technologies, advances in pharmacotherapy, and awareness of the implications of implantation techniques have markedly reduced the risk of stent failure, both in the form of stent thrombosis (ST) and in-stent restenosis (ISR). However, given the number of percutaneous coronary interventions (PCI) performed worldwide every year, ST and ISR, albeit occurring at a fairly low rate, represent a public health problem even with contemporary DES platforms. The understanding of mechanisms and risk factors for these two PCI complications has been of fundamental importance for the parallel evolution of stent technologies. Risk factors associated with ST and ISR are usually divided into patient-, lesion-, device- and procedure-related. A number of studies have shown how certain risk factors are related to early (1 month) versus late/very late ST (between 1 month and 1 year and >1 year, respectively). However, more research is required to conclusively show the role of time-dependence of risk factors also in the incidence of ISR (early [1 year] or late [>1 year]). A thorough risk assessment is required due to the complex etiology of ST and ISR. The most effective strategy to treat ST and ISR is still to prevent them; hence, it is crucial to identify patient-, lesion-, device- and procedure-related predictors.

24-Month Clinical Follow-Up and Mechanistic Insights From Intravascular Imaging Following Coronary Implantation of the Novel DynamX Bioadaptor Platform

BACKGROUND/PURPOSE

Conventional stents "cage" the coronary arteries, impairing vascular function and physiology. The DynamX Bioadaptor is a cobalt‑chromium platform with uncaging elements, designed to improve arterial pulsatility, vasomotion, compliance, and positive adaptive remodelling which may attenuate late clinical events associated with the caging of arteries through conventional stents. We present the first 24-month outcomes of this device.

METHODS/MATERIALS

This European multicenter study enrolled 50 patients with 50 de novo lesions treated with the DynamX Bioadaptor. Clinical follow-up is scheduled until 36 months and imaging follow-up was performed at 9-12 months.

RESULTS

24-month endpoints were target lesion failure (2 cardiac deaths), myocardial infarction (1 non-target vessel myocardial infarction), target vessel revascularisation (n = 0), and definite or probable device thrombosis (n = 0). No endpoint events occurred beyond 9 months. Paired intravascular ultrasound analysis of 18 patients from a single center revealed a 0.22 mm² increase in device cross-sectional area at 9-12 months. Pulsatility analysis showed an increase of in-device lumen area change by 46 % compared to the caged post-procedural configuration, reducing the compliance mismatch between the treated and not-treated vessel segments (segmental compliance). Likewise, vasomotion in response to nitroglycerin improved from 0.03mm² post-procedure to 0.17mm² at follow-up.

CONCLUSIONS

24-month clinical data demonstrate promising safety and efficacy of the DynamX Bioadaptor. Imaging data confirmed its unique capacity to improve arterial pulsatility, vasomotion, compliance and positive adaptive remodelling after "uncaging" which might have led to the promising clinical outcomes that need to be confirmed in larger studies.

Drug-Eluting Stent Restenosis: Modern Approach to a Classic Challenge

In-stent restenosis (ISR) is a recognized complication following percutaneous coronary intervention in which the luminal diameter is narrowed through neointimal hyperplasia and vessel remodeling. Although rates of ISR have decreased in most recent years owing to newer generation drug-eluting stents, thinner struts, and better intravascular imaging modalities, ISR remains a prevalent dilemma that proves to be challenging to manage. Several factors have been proposed to contribute to ISR formation, including mechanical stent characteristics, technical factors during the coronary intervention, and biological aspects of drug-eluting stents. Presentation of ISR can range from asymptomatic to late myocardial infarction and could be difficult to differentiate from acute thrombus formation. No definite guidelines are present on the management of ISR. In this review, we will discuss the mechanisms underlying ISR and provide insight into patient-related and procedural risk factors contributing to ISR, in addition to highlighting common treatment approaches utilized in the management of ISR.

Intravascular Imaging for Guiding In-Stent Restenosis and Stent Thrombosis Therapy

Advances in stent technology and the design of endovascular devices with thinner struts, anti-inflammatory and antithrombotic polymers, and better drug kinetics have enhanced the safety and efficacy of the second-generation drug-eluting stents and broadened their use in the therapy of high-risk patients and complex anatomies. However, despite these developments, in-stent restenosis and stent thrombosis remain the Achilles' heel of percutaneous coronary intervention, with their cumulative incidence reaching up to 10% at 5 years following percutaneous coronary intervention. The treatment of stent failure poses challenges and is associated with a worse prognosis than conventional percutaneous coronary intervention. Several studies have recently highlighted the value of intravascular imaging in identifying causes of stent failure, underscored its role in treatment planning, and registries have shown that its use may be associated with better clinical outcomes. The present review aims to summarize the evidence in the field; it discusses the value of intravascular imaging in identifying the mechanisms of in-stent restenosis and stent thrombosis in assessing the morphological characteristics of neointima tissue that appears to determine long-term outcomes in evaluating procedural results, and presents the findings of studies supporting its value in guiding therapy in stent failure.

How to deal with vessel diameter mismatch in left main bifurcation stenting

Left main coronary artery percutaneous coronary intervention is particularly complex when stenting across the distal bifurcation is required in the presence of a diameter mismatch between the proximal main and distal branches. A suboptimal procedural result increases the risk of thrombosis and restenosis. Considering the paucity of data published on this topic, our objective was to provide technical solutions to deal with this complex anatomy. We described four cases showing the use of devices and techniques which allowed us to overcome a diameter discrepancy between adjacent coronary segments: (1) self-expanding nitinol stent; (2) stent platform with noteworthy expansion capacity; (3) the 'extended skirt' technique; (4) the 'trouser-leg' technique. In conclusion, the use of specific strategies and devices allows a safe and effective approach to be used to perform treatment that respects the coronary anatomy, and to optimize percutaneous coronary intervention results in complex scenarios.

Impact of Reference Mismatch on Procedure Outcomes of Percutaneous Coronary Intervention

A significant mismatch between proximal and distal reference lumen diameters of the target lesion may pose challenges during percutaneous coronary intervention (PCI) and therefore influence the outcomes. We investigated total 1706 lesions underwent IVUS guided percutaneous coronary intervention, that were divided into 2 groups, including 411 lesions in Mismatch group and 1295 lesions in Non-Mismatch group. After propensity score matching, 397 lesions in each group were selected for final data set. The analysis showed that Mismatch group PCI required more frequently use of post-stenting optimization (79.6% vs 53.9%, P < .001) using higher max pressure (19.5 ± 3.9 vs 16.7 ± 3.7 atm, P < .001). Besides, Mismatch group also encountered more PCI major complications (7.8% vs 4.0%, P = .024) and lower procedure success rate (91.4% vs 95.5%, P = .022). On final angiogram, Mismatch group had smaller minimum lumen diameter (2.62 ± .45 vs 2.90 ± .57 mm, P < .001) and lower angiographic success rate (93.2% vs 96.7%, P = .023). On final IVUS, Mismatch group had higher rate of incomplete stent apposition and stent edge dissection (6.3% vs 3.0%, P = .029 and 2.5% vs .5%, P = .021, respectively). In conclusion, reference mismatch posed significant challenging during PCI that led to unfavorable procedural outcomes. These impacts may translate into long-term clinical implications that need to be addressed in future studies.

Incidence of coronary drug-eluting stent fracture: A systematic review and meta-analysis

Background

Reported evidence of coronary stent fracture (CSF) has increased in recent years. The purpose of this study was to determine reliable estimates of the overall incidence of CSF.

Methods and results

The MEDLINE, Embase and Cochrane databases were searched until March 18, 2022. Pooled estimates were acquired using random effects models. Meta-regression and subgroup analysis were used to explore sources of heterogeneity, and publication bias was evaluated by visual assessment of funnel plots and Egger’s test. Overall, 46 articles were included in this study. Estimates of CSF incidence were 5.5% [95% confidence interval (CI): 3.7–7.7%] among 39,953 patients based on 36 studies, 4.8% (95% CI: 3.1–6.8%) among 39,945 lesions based on 29 studies and 4.9% (95% CI: 2.5–9.4%) among 19,252 stents based on 8 studies. There has been an obvious increase in the incidence of CSF over the past two decades, and it seems that the duration of stent placement after stent implantation has no impact on incidence estimation.

Conclusion

The incidence of CSF was 5.5% among patients, 4.8% for lesions and 4.9% for stents and increased over the past 20 years. The duration of stent placement after stent implantation was found to have no impact on the incidence of CSF, but drug-eluting stent (DES) types and right coronary artery (RCA) lesions influenced the pooled incidence.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022311995], identifier [CRD42022311995].

Intravascular imaging in coronary stent restenosis: Prevention, characterization, and management

Despite the introduction of drug-eluting stents to combat the neointimal hyperplasia that occurred after BMS implantation, in-stent restenosis is still encountered in a significant number of patients, particularly as increasingly complex lesions are tackled by percutaneous coronary intervention. Many biological and mechanical factors interplay to produce restenosis, some of which are avoidable. Intravascular imaging provided unique insights into various forms of stent-related mechanical issues that contribute to this phenomenon. From a practical perspective, intravascular imaging can therefore help to optimize the stenting procedure to avert these issues. Moreover, once the problem of restenosis eventuates, imaging can guide the management by tackling the underlying identified mechanism. Finally, it can be used to evaluate the re-intervention results. Nevertheless, with the emergence of different treatment options, more evidence is needed to define patient/lesion-specific characteristics that may help to tailor treatment selection in a way that improves clinical outcomes.

Response to pre-dilatation with POBA can predict target lesion revascularization after DCB angioplasty for de novo small coronary artery lesions

Objective

To assess the determinants of target lesion revascularization (TLR) after drug-coated balloon (DCB) angioplasty for de novo small coronary artery lesions.

Methods

This retrospective study enrolled consecutive lesions from patients that were in a stable condition and had undergone successful DCB treatment for de novo small coronary artery lesions. The study endpoint was TLR and major adverse cardiac events at 12 months.

Results

A total of 68 patients with 83 lesions were enrolled in the study. Of these, 11 (13.3%) lesions required TLR. Mean ± SD pre-dilatation balloon diameters were similar in the non-TLR (2.33 ± 0.72 mm) and TLR (2.18 ± 0.36 mm) groups. A comparison of the two groups showed that post/pre-lumen area ratio during pre-dilatation (%) by plain old balloon angioplasty (POBA) was significantly and negatively associated with TLR and the optimal cut-off point was 170%. Cox proportional hazard and multivariate regression analyses showed that post/pre-lumen area ratio was the only independent predictor of TLR (hazard ratio 0.9318; 95% confidence interval 0.9001, 0.9645).

Conclusion

Greater pre-dilatation using POBA, assessed as the post/pre-lumen area ratio, may be independently associated with a lower 12-month TLR rate in patients undergoing DCB angioplasty for de novo small coronary lesions.

Management of in-stent restenosis

In-stent restenosis (ISR) remains the most common cause of stent failure after percutaneous coronary intervention (PCI). Recent data suggest that ISR-PCI accounts for 5-10% of all PCI procedures performed in current clinical practice. This State-of-the-Art review will primarily focus on the management of ISR but will begin by briefly discussing diagnosis and classification. We then move on to detail the evidence base underpinning the various therapeutic strategies for ISR before finishing with a proposed ISR management algorithm based on current scientific data.

An experimental investigation into the physical, thermal and mechanical degradation of a polymeric bioresorbable scaffold

This study presents a comprehensive evaluation of the mechanical, micro-mechanical and physical properties of Reva Medical Fantom Encore Bioresorbable Scaffolds (BRS) subjected to a thermally-accelerated degradation protocol. The Fantom Encore BRS were immersed in phosphate buffered saline solution at 50 °C for 112 days with radial compression testing, nanoindentation, differential scanning calorimetry, gel permeation chromatography and mass loss characterisation performed at consecutive time points. In the initial stages of degradation (Days 0-21), the Fantom Encore BRS showed increases in radial strength and stiffness, despite a substantial reduction in in molecular weight, with a slight increase in the melt temperature also observed. In the second phase (Days 35-54), the radial strength of the BRS samples were maintained despite a continued loss in molecular weight. However, during this phase, the ductility of the stent showed a reduction, with stent fracture occurring earlier in the crimp process and with lower amounts of plastic deformation evident under visual examination post-fracture. In the final phase (Days 63-112), the load-bearing capacity of the Fantom Encore BRS showed continued reduction, with decreases in radial stiffness and strength, and drastic reduction in the work-to-fracture of the devices. Throughout each phase, there was a steady increase in the relative crystallinity, with limited mass loss until day 112 and only minor changes in glass transition and melt temperatures. Limited changes were observed in nano-mechanical properties, with measured local elastic moduli and hardness values remaining largely similar throughout degradation. Given that the thermally-accelerated in vitro conditions represented a four-fold acceleration of physiological conditions, these results suggest that the BRS scaffolds could exhibit substantially brittle behaviour after ∼ one year of implantation.

Effect of Hinge Motion on Stent Edge-Related Restenosis After Right Coronary Artery Treatment in the Current Drug-Eluting Stent Era

BACKGROUND

Stent edge-related restenosis (SER) remains a potential limitation of drug-eluting stent (DES). Hinge motion at the stent edge could lead to mechanical stress and contribute to incidents of SER. We investigated the effect of hinge motion on SER after implantation of current-generation DES in the right coronary artery (RCA), where excessive vessel movement is commonly observed.

METHODS AND RESULTS

Of 647 consecutive lesions in the RCA treated with second-generation or later DESs, 426 with follow-up angiography were included in this study. Intravascular imaging analysis was performed for 584 stent edges and reference segments. Binary restenosis occurred in 42 lesions (9.9%), and 55% were SERs. The hinge angle was significantly larger in the SER group than in the other restenosis or the no-restenosis group (17.9° vs. 11.6° and 10.6°, respectively; P<0.001). Lesions with an excessive hinge angle (>11.5°) had an increased rate of target lesion revascularization (19.1% vs. 7.2%; P<0.001) during the median follow-up period of 1,578 days. In per-edge analysis, hinge angle and residual plaque burden were independent predictors of SER. The coexistence of excessive hinge motion and residual plaque burden had a synergistic effect on stenotic progression in quantitative angiographic analysis (Pinteraction<0.001) at follow-up angiography.

CONCLUSIONS

Substantial stress determined by angulation at a stent edge and its interaction with residual plaque can be considered as one plausible mechanism for SER.

Adaptive coronary artery rotational motion through uncaging of a drug-eluting bioadaptor aiming to reduce stress on the coronary artery

BACKGROUND

Caged drug-eluting stents impede natural coronary rotational motion and increase vessel stress, which can contribute towards adverse events. The DynamX™ Drug-Eluting Bioadaptor is a cobalt‑chromium platform with a novel mechanism that uncages the vessel after the bioresorbable coating resorbs over six months. This study aimed to analyze the effects of the rotational uncaging in a finite element analysis (FEA) model, validating its effect on coronary artery rotational motion through in-vivo stationary intravascular ultrasound (IVUS).

METHODS

Maximum Von Mises stresses were measured in an FEA model and compared for caged and uncaged bioadaptors. Stationary IVUS images from 20 patients enrolled in a single center were acquired post implantation and at 9-12-month follow-up to evaluate coronary artery rotational motion.

RESULTS

The FEA model showed that rotational uncaging of the bioadaptor reduces peak stress by 70%. In-vivo, the in-bioadaptor segment was significantly distorted post-implant compared to the native distal and proximal vessel, measured by IVUS: The sum of clockwise and counterclockwise rotational motion (net-effect rotational motion) was -2.7 ± 4.3° versus 0.5 ± 5.0° (proximal vessel), p = 0.036, and versus 0.2 ± 3.8° (distal vessel), p = 0.042. At follow up, when the bioadaptor had uncaged, the vessel returned towards its equilibrium (net-effect rotational motion -0.2 ± 5.6°), with no significant difference between the vessel segments.

CONCLUSIONS

In concurrence with the FEA observation, the in-vivo IVUS-analysis demonstrates that uncaging of the bioadaptor affects coronary artery rotational motion. The effect of these findings on reducing clinical events warrants further investigation.

The resorbable magnesium scaffold Magmaris in acute coronary syndrome: An appraisal of evidence and user group guidance

Bioresorbable scaffolds provide transient vessel support without the long-term limitations of permanent metallic drug-eluting stents. The sirolimus-eluting resorbable magnesium scaffold Magmaris is the only CE-marked metallic bioresorbable scaffold and provides short-term lumen support before being completely bioresorbed. To date, clinical trial results have demonstrated low adverse event rates in patients with simple coronary lesions. Seven European centers with large experience in Magmaris implantation, combined efforts in an informal collaboration to evaluate and appraise clinical data currently available regarding the performance of Magmaris in patients presenting with acute coronary syndromes, and to supply user-advice on patient selection and optimal implantation practice.

Angiography-Based 4-Dimensional Superficial Wall Strain and Stress: A New Diagnostic Tool in the Catheterization Laboratory

A novel method for four-dimensional superficial wall strain and stress (4D-SWS) is derived from the arterial motion as pictured by invasive coronary angiography. Compared with the conventional finite element analysis of cardiovascular biomechanics using the estimated pulsatile pressure, the 4D-SWS approach can calculate the dynamic mechanical state of the superficial wall in vivo, which could be directly linked with plaque rupture or stent fracture. The validation of this approach using in silico models showed that the distribution and maximum values of superficial wall stress were similar to those calculated by conventional finite element analysis. The in vivo deformation was validated on 16 coronary arteries, from the comparison of centerlines predicted by the 4D-SWS approach against the actual centerlines reconstructed from angiograms at a randomly selected time-point, which demonstrated a good agreement of the centerline morphology between both approaches (scaling: 0.995 ± 0.018 and dissimilarity: 0.007 ± 0.014). The in silico vessel models with softer plaque and larger plaque burden presented more variation in mean lumen diameter and resulted in higher superficial wall stress. In more than half of the patients (n = 16), the maximum superficial wall stress was found at the proximal lesion shoulder. Additionally, in three patients who later suffered from acute coronary syndrome, the culprit plaque rupture sites co-localized with the site of highest superficial wall stress on their baseline angiography. These representative cases suggest that angiography-based superficial wall dynamics have the potential to identify coronary segments at high-risk of plaque rupture and fracture sites of implanted stents. Ongoing studies are focusing on identifying weak spots in coronary bypass grafts, and on exploring the biomechanical mechanisms of coronary arterial remodeling and aneurysm formation. Future developments involve integration of fast computational techniques to allow online availability of superficial wall strain and stress in the catheterization laboratory.

Branch Pulmonary Artery Jailing During Patent Ductus Arteriosus Stenting: Recruitment and Immediate Outcomes

BACKGROUND

Branch pulmonary artery (PA) occlusion during patent ductus arteriosus (PDA) stenting procedure is the main reason why branch PA origin stenosis was considered as a contraindication for PDA stenting. This study was designed to assess the incidence of branch PA jailing during PDA stenting for cyanotics with duct-dependent pulmonary circulation and its immediate outcome.

METHODS

All the completed PDA stenting patients in our hospital between April 2017 and June 2019 were retrospectively analyzed for branch PA jailing and its outcome.

RESULTS

Of 63 completed PDA stenting, there was branch PA jailing in 13 (20.6%) patients, all successfully recruited either by strut dilatation or by surgery. The median duration of ventilation was 16 (interquartile range [IQR]: 8-22) hours for jailed patients and 17.5 (IQR: 5.25-34.25) hours for nonjailed patients (P = .978). Median intensive care unit [ICU] stay was 69 (IQR: 47.75-96) hours for jailed patients and 79.5 (IQR: 66.75-135.25) hours for nonjailed patients (P = .394). Procedural mortality was 1 (7.6%) for jailed patients and 3 (6%) for nonjailed patients. Since all the jailed pulmonary arteries were recruited, there was proportionate growth of branch PA till the most recent follow-up.

CONCLUSION

Jailing of branch PA does not increase the ventilation duration, ICU stay, or mortality risk if recruited immediately. Proportionate growth of branch PAs can be achieved in spite of jailing, if addressed aggressively. Branch PA stenosis should not be considered as a contraindication for PDA stenting.

Stent Fracture Induced Infected Pseudo Coronary Artery Aneurysm with Massive Abscess Successfully Treated by Coronary Stent Graft

Infected pseudo coronary artery aneurysm (CAA) is extremely rare, and currently, there is no established treatment. We experienced a rare case of an infected pseudo CAA brought on due to a stent fracture. Following prolonged successful antimicrobial administration, which proved effective in successfully treating the patient, we performed coronary stent graft placement. Although a surgical procedure should fundamentally be the first course of action considered in such cases, when there are concerns as to the degree of invasiveness, our strategy represents a viable option.

Coronary Stent Strut Fractures: Classification, Prevalence and Clinical Associations

Introduction. The frequency, characteristics and clinical implications of Strut fractures (SFs) remain incompletely understood. Methods and results. A total of 185 (160 patients) newer-generation drug-eluting stents (DES) were imaged. SFs were found in 21 DES (11.4%) and were classified in four patterns: one single stacked strut (41%); two or more stacked struts (23%); deformation without gap (27%); transection (9%). In multivariable analysis, calcific and bifurcation lesions were associated with SF in DES (OR: 3.5 [1.1–11] and 4.0 [2.2–7.2], p < 0.05). Device eccentricity and asymmetry as well as optical coherence tomography (OCT) features of impaired strut healing were also associated with SF. The prevalence of fractures was similar in a set of 289 bioresorbable scaffolds (BRS). In a separate series of 20 device thromboses and 36 device restenoses, the prevalence of SF was higher (61.2% of DES and 66.7% of BRS, p < 0.001 for both), with a higher frequency of complex SF patterns (p < 0.0001). In logistic regression analysis, fractures were a correlate of device complications (p < 0.0001, OR = 24.9 [5.6–111] for DES and OR = 6.0 [1.8–20] for BRS). Discussion. The prevalence of OCT-diagnosed SF was unexpectedly high in the setting of elective controls and it increased by about three-fold in the setting of device failure. Fractures were associated with increased lesion complexity and device asymmetry/eccentricity and were more frequent in the setting of device failure such as restenosis and thrombosis.

Comparison of intravascular ultrasound-guided with angiography-guided double kissing crush stenting for patients with complex coronary bifurcation lesions: Rationale and design of a prospective, randomized, and multicenter DKCRUSH VIII trial

BACKGROUND

Double kissing (DK) crush approach for patients with coronary bifurcation lesions, particularly localized at distal left main or lesions with increased complexity, is associated with significant reduction in clinical events when compared with provisional stenting. Recently, randomized clinical trial has demonstrated the net clinical benefits by intravascular ultrasound (IVUS)-guided implantation of drug-eluting stent in all-comers. However, the improvement in clinical outcome after DK crush treatment guided by IVUS over angiography guidance for patients with complex bifurcation lesions have never been studied in a randomized fashion.

TRIAL DESIGN

DKCRUSH VIII study is a prospective, multicenter, randomized controlled trial designed to assess superiority of IVUS-guided vs angiography-guided DK crush stenting in patients with complex bifurcation lesions according to DEFINITION criteria. A total of 556 patients with complex bifurcation lesions will be randomly (1:1 of ratio) assigned to IVUS-guided or angiography-guided DK crush stenting group. The primary end point is the rate of 12-month target vessel failure, including cardiac death, target vessel myocardial infarction, or clinically driven target vessel revascularization. The secondary end points consist of the individual component of primary end point, all-cause death, myocardial infarction, and in-stent restenosis. The safety end point is the incidence of definite or probable stent thrombosis. An angiographic follow-up will be performed for all patients at 13 months and clinical follow-up will be continued annually until 3 years after the index procedure.

CONCLUSIONS

DKCRUSH VIII trial is the first study designed to evaluate the differences in efficacy and safety between IVUS-guided and angiography-guided DK crush stenting in patients with complex true bifurcation lesions. This study will also provide IVUS-derived criteria to define optimal DK crush stenting for bifurcation lesions at higher complexity.

Overlapping Drug-Eluting Stent Is Associated with Increased Definite Stent Thrombosis and Revascularization: Results from 15,561 Patients in the AUTHENTIC Study

PURPOSE

This study was to analyze the incidence of definite stent thrombosis (ST) after the implantation of drug-eluting stents (DESs) and cutoff value of overlapping length for predicting definite ST. An overlapping stent is associated with a high rate of clinical events after DES implantation compared with a non-overlapping stent. However, the rates of definite ST and clinical outcomes from a large patient population remain underreported.

METHODS

A total of 15,561 patients with 24,183 lesions who underwent DES implantation from January 2005 to February 2017 were retrospectively included in 5 tertiary hospitals in China. The main endpoint was the incidence of definite ST after procedures.

RESULTS

With a median of 1932 (IQR = 1194-2929) days, clinical follow-up was available in 7484 patients in the overlap group and in 8077 patients in the non-overlap group. The rates of definite ST were 3.1% in the overlap group and 1.2% in the non-overlap group (HR: 2.67 (95% CI: 2.11-3.38), p < 0.001). Of the 24,183 treated lesions, the incidences of definite ST were 2.4% in the overlap group and 0.9% in the non-overlap group (HR: 2.96 (95% CI: 2.38-3.69), p < 0.001). Stent overlap was associated with a higher rate of target lesion revascularization (TLR) (9.4%) compared with stent non-overlap (6.4%, p < 0.001). The length of overlapping stent ≥ 2.93 mm strongly correlated with definite ST.

CONCLUSION

The present study shows that overlapping DES increases definite ST and revascularization in patients during long-term follow-up. In addition, the longer overlapping zone was associated with worse clinical outcomes.

Utility of a novel high pressure non-compliant balloon for tibial atherosclerotic lesions in Asian patients with chronic limb threatening ischaemia

Background: The aim was to evaluate the safety and efficacy of a high pressure, non-compliant balloon in the treatment of infrapopliteal occlusive disease in Asian patients with chronic limb threatening ischaemia (CLTI) from Singapore. Patients and methods: Prospective, multi-centre, single arm, non-randomized study. Immediate technical success, 6-month primary vessel patency (determined by Duplex ultrasonography), limb salvage, one-year clinically driven target lesion re-intervention (TLR) and amputation free survival (AFS) were the efficacy endpoints of interest. Results: 86 patients (63% males, mean age 68.9 ± 9.9 years) were enrolled over a 15-month period. Diabetes mellitus (DM) and end-stage renal failure (ESRF) were present in 94% and 38% of patients respectively. All had some degree of tissue loss at baseline (Rutherford scale 5 and 6 = 91% and 9% respectively). Of the 86 legs, 72% had 3 crural vessel disease and 84% had moderate/severe vessel wall calcification. 90% had > = 1 TASC D tibial lesion. Acute technical success was 89%. One month mortality was 3.5% and one-year freedom from TLR was 91%. 6-month tibial patency was 73%. 54/66 (82%) patients had at least one target treated tibial artery open at 6 months. A lower baseline toe pressure (OR 1.03, 95%CI 1.00-1.05) and elastic recoil post angioplasty (OR 0.20, 95%CI 0.05-0.79) were associated with a worse 6 month tibial patency. One-year AFS was 67%. 47/66 (71%) patients had a clinical improvement of at least one Rutherford class at 6 months and 52/59 (88%) experienced complete wound healing at 12 months. Conclusions: Use of a high pressure non-compliant balloon is safe and efficacious in treating highly complex infra-popliteal atherosclerotic lesions in an otherwise challenging population of CLTI patients with a high incidence of DM and ESRF. It is associated with highly satisfactory acute technical success, 6-month target lesion patency and one-year limb salvage.

Intravascular Ultrasound-guided Versus Angiography-guided Percutaneous Coronary Intervention: Evidence from Observational Studies and Randomized Controlled Trials

Coronary angiography has been considered the gold standard for the diagnosis of coronary artery disease and guidance of percutaneous coronary intervention (PCI). However, 2D-projection angiography cannot completely reflect the 3D coronary lumen. Intravascular ultrasound (IVUS) can overcome a number of limitations of coronary angiography by providing more information about the dimensions of the vessel lumen, plaque characteristics, stent deployment, and the mechanisms of device failure. Growing data from observational studies and randomized controlled trials have confirmed the clinical benefit of IVUS guidance during PCI. This article summarizes the evidence regarding IVUS guidance to highlight its advantages and to support the use of IVUS during PCI.

The coronary resorbable magnesium scaffold Magmaris®: what we have learnt (so far…)

Bioresorbable scaffold (BRS) technology provides transient vessel support with drug-delivery capability without the long-term limitations of the permanent metallic drug-eluting stents (DES). Numerous scaffolds have been developed and investigated by device manufacturers, many of which, due to device deficiencies, have fallen by the wayside. This short review will focus on the resorbable magnesium scaffold Magmaris^® the only metallic bioresorbable scaffold currently available, providing an evaluation of the most up to date clinical data whilst also briefly highlighting learning points regarding the ideal patient and lesion choice and optimal implantation technique.

A modified predilation, sizing, and postdilation scoring system for patients undergoing metallic drug-eluting stent implantations

OBJECTIVE

This study sought to assess whether the predilation, scaffold/stent sizing, and postdilation (PSP) score for bioresorbable scaffold (BRS) implantation was associated with outcomes following metallic drug-eluting stent (DES) implantation.

BACKGROUND

The PSP score is associated with patients' prognoses after BRS implantation.

METHODS

This study involved 2,348 patients who underwent biodegradable polymer DES implantations during the PANDA III trial. The optimal PSP technique was defined according to previous studies of BRS implantations. The main outcome was target lesion failure (TLF) that comprised cardiac death, target-vessel myocardial infarction, or ischemia-driven target lesion revascularization.

RESULTS

Twenty-five (1.1%) patients fulfilled all the PSP criteria. The BRS-derived PSP score was of limited prognostic value for 2-year TLF after metallic DES implantation; optimal sizing was a protective factor, but optimal predilation was a risk factor. We built a new PSP model for DESs by identifying the following risk factors: predilation performed with a residual stenosis ≥70% or a balloon-to-quantitative coronary angiography (QCA)-determined reference vessel diameter (RVD) ratio >1:1, sizing performed with an RVD <2.25 mm or a stent diameter >0.25 mm wider than the QCA-RVD, a postprocedural stenosis diameter ≥30%, age, and the baseline SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery (SYNTAX) score. The new PSP scoring system predicted 2-year TLF (area under the curve, 0.69; 95% confidence interval, 0.65-0.73); a cutoff value of 19.2 points identified high-risk patients.

CONCLUSIONS

The new PSP scoring system, based on redefined PSP criteria, age, and the SYNTAX score, could help optimize metallic DES implantations.

Efficacy and Safety of Ultrathin, Bioresorbable-Polymer Sirolimus-Eluting Stents Versus Thin, Durable-Polymer Everolimus-Eluting Stents for Coronary Revascularization of Patients With Diabetes Mellitus

Patients with diabetes mellitus are prone to increased adverse outcomes after percutaneous coronary intervention, even with contemporary drug-eluting stents. Randomized controlled trials have demonstrated comparable clinical outcomes between an ultrathin bioresorbable-polymer sirolimus-eluting stent (BP-SES) and a thin-strut durable-polymer everolimus-eluting stent (DP-EES) that has specific labeling for patients with diabetes. We aimed to evaluate the safety and efficacy of the BP-SES in patients with diabetes mellitus. To determine the performance of the BP-SES in diabetic patients, patient-level data from the BIOFLOW II, IV, and V randomized controlled trials were pooled. The primary end point was target lesion failure (TLF), defined as the composite of cardiovascular death, target-vessel myocardial infarction, ischemia-driven target lesion revascularization, and definite or probable stent thrombosis, at 1 year. Among 1,553 BP-SES and 791 DP-EES patients, 757 diabetic patients were identified. Of the diabetic patients included in this analysis (494 BP-SES vs 263 DP-EES), the proportion of insulin- and noninsulin-treated patients was similar between groups. The 1-year TLF rate in the diabetic population was 6.3% in the BP-SES group and 8.7% in the DP-EES group (hazard ratio 0.82, 95% confidence interval 0.047 to 1.43, p = 0.493). There were no significant differences, based on stent type or diabetes treatment regimen, in TLF hazards. In a patient-level pooled analysis of the diabetic population from randomized trials, 1-year clinical safety and efficacy outcomes were similar in patients treated with ultrathin BP-SES and thin-strut DP-EES.

Validating Fatigue Safety Factor Calculation Methods for Cardiovascular Stents

Evaluating risk of fatigue fractures in cardiovascular implants via nonclinical testing is essential to provide an indication of their durability. This is generally accomplished by experimental accelerated durability testing and often complemented with computational simulations to calculate fatigue safety factors (FSFs). While many methods exist to calculate FSFs, none have been validated against experimental data. The current study presents three methods for calculating FSFs and compares them to experimental fracture outcomes under axial fatigue loading, using cobalt-chromium test specimens designed to represent cardiovascular stents. FSFs were generated by calculating mean and alternating stresses using a simple scalar method, a tensor method which determines principal values based on averages and differences of the stress tensors, and a modified tensor method which accounts for stress rotations. The results indicate that the tensor method and the modified tensor method consistently predicted fracture or survival to 107 cycles for specimens subjected to experimental axial fatigue. In contrast, for one axial deformation condition, the scalar method incorrectly predicted survival even though fractures were observed in experiments. These results demonstrate limitations of the scalar method and potential inaccuracies. A separate computational analysis of torsional fatigue was also completed to illustrate differences between the tensor method and the modified tensor method. Because of its ability to account for changes in principal directions across the fatigue cycle, the modified tensor method offers a general computational method that can be applied for improved predictions for fatigue safety regardless of loading conditions.

Coronary artery rotation in native and stented porcine coronary arteries

INTRODUCTION

Coronary arteries are exposed to several complex biomechanical forces during the cardiac cycle. These biomechanical forces potentially contribute to both native coronary artery disease, development of atherosclerosis and eventual stent failure. The aim of the present study was to characterize and define coronary artery axial rotation and the effect of stent implantation on this biomechanical factor.

METHODS

Intravascular ultrasound (IVUS) images were obtained from porcine coronary arteries and analyzed in ultrasound analysis software used to evaluate myocardial strain and torsion in echocardiography. In this study the software was utilized for a novel application to evaluate coronary artery rotation and time-to-peak (TTP) rotation in porcine coronary arteries. Clockwise (CW) and counterclockwise (CCW) rotation of coronary arteries during the cardiac cycle and (TTP) rotation were measured.

RESULTS

A total of 11 (4 LAD, 4 LCX, 3 RCA) coronary artery segments were independently analyzed pre- and post-stent implantation for a total of 22 IVUS runs. CW and CCW rotation and TTP varied widely within coronary artery segments and between different coronary arteries. Stent implantation impacted degree, direction and TTP of coronary rotation. Measurement reliability was assessed and the intraclass correlation coefficient for maximum average CCW was 0.990 (95% confidence interval 0.980-0.996, P < 0.0001), indicating excellent agreement.

CONCLUSIONS

Coronary arteries display wide spectrum of CW and CCW rotation during the cardiac cycle. Coronary stents impact the degree and direction of coronary artery rotation. The implications of these findings on development of atherosclerosis and stent failure require further investigation.

Association of stent-induced changes in coronary geometry with late stent failure: Insights from three-dimensional quantitative coronary angiographic analysis

BACKGROUND

The relationship between vessel angulation and large changes in vessel geometry after stent implantation and the occurrence of stent failure still remains unclear. We sought to investigate the association of the change in the coronary bending angle after stenting and the risk for late stent failure by three-dimensional quantitative coronary angiography (3D QCA).

METHODS

The bending angle in coronary lesions that presented with late stent failure and those without stent failure was computed during the cardiac cycle, before and after stenting using a recently developed 3D QCA software.

RESULTS

A total of 40 lesions with stent failure (cases) were successfully matched to 47 lesions without stent failure (controls).The mean duration to follow-up coronary angiography was 1,011 days in cases and 1,109 days in the control group (P = 0.14). In stent failure, the systolic bending angle after stenting was smaller (14.45° [12.18, 17.68] versus 18.20° [14.00, 20.30], P = 0.01), while the stent-induced change in systolic bending angle was significantly larger (4.15° [1.13, 7.20] versus 1.80° [-1.90, 4.40], P = 0.004). Multivariable logistic regression analysis suggested that systolic bending angle after stenting (odds ratio: 0.88; 95% CI: 0.79-0.99; P = 0.03), and decrease in systolic bending angle after stenting (odds ratio: 1.13; 95% CI: 1.02-1.26; P = 0.03) were predictors of stent failure.

CONCLUSIONS

Our study suggests that a change in the natural tortuous course of the coronaries by stent implantation with the decrease in coronary bending angle is a potentially major contributor in stent failure.

Coronary Artery Aneurysm Caused by a Stent Fracture

Coronary stent fracture (SF) is rare as a complication of percutaneous coronary intervention (PCI), and its adverse events are increasingly being recognized with the development in devices of PCI. The major adverse events caused by SFs are in-stent restenosis due to neointimal overgrowth caused by poor drug delivery.^1,2) A coronary artery aneurysm (CAA) is a rare complication of SF, but may lead to lethal events such as acute coronary syndrome or rupture of the CAA further leading to cardiac tamponade.^3-5) However, the management of CAAs is controversial with or without SF.⁶⁾ Herein, we report a case of a CAA caused by an SF and discuss the management of CAA complicated with SF, along with a literature review. We suggest that surgical treatment should be considered the higher-priority strategy in the cases of CAA with SF as compared to CAA without SF.