Impact of Sirolimus-Eluting Stent Fracture on 4-Year Clinical Outcomes

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].

Adropin inhibits the phenotypic modulation and proliferation of vascular smooth muscle cells during neointimal hyperplasia by activating the AMPK/ACC signaling pathway

In-stent restenosis (ISR) remains an inevitable problem for some patients receiving drug-eluting stent (DES) implantation. Intimal hyperplasia is an important biological cause of ISR. It has been previously reported that adropin is a potentially protective factor in cardiovascular disease. Therefore, the present study investigated the function of adropin in inhibiting smooth muscle cell (SMC) phenotype modulation and proliferation, causing intimal hyperplasia. A total of 56 patients who visited the hospital consecutively (25 with ISR and 31 without ISR), who were followed up between April 2016 and March 2019, 1 year following DES, were analyzed to evaluate the association between in-stent neointimal volume and adropin serum levels. Rat aorta smooth muscle cells (RASMCs) were used to determine the effects of adropin on their phenotypic modulation and proliferation using western blot, MTT, PCR and immunofluorescence analyses. Adropin serum levels in the ISR group were significantly lower than those in the non-ISR group. Furthermore, linear regression analysis revealed that only adropin levels were negatively associated with neointimal volume in both groups. The overall adropin levels of the 56 patients and the percentages of neointimal volume revealed a strong negative association. In vitro, adropin suppressed angiotensin II (Ang II)-induced phenotypic modulation in RASMCs by restoring variations of osteopontin and α-smooth muscle actin. Furthermore, compared with the Ang II group, adropin markedly decreased the percentage of G₂/M-phase cells. Finally, adropin negatively regulated the phenotypic modulation and proliferation of RASMCs via the AMP-activated protein kinase/acetyl-CoA carboxylase (AMPK/ACC) signaling pathway. In conclusion, an independent, negative association was revealed between adropin and intimal hyperplasia; specifically, adropin inhibited the phenotypic modulation and proliferation of RASMCs by activating the AMPK/ACC signaling pathway. Therefore, adropin may be used as a potential predictor and therapeutic target for intimal hyperplasia and ISR.

Coronary Stent Failure: Fracture, Compression, Recoil, and Prolapse

Current-generation coronary drug-eluting stents are associated with low rates of restenosis and target lesion revascularization. However, several mechanisms of stent failure remain clinically important. Stent fracture may occur in areas of excessive torsion or angulation. Longitudinal stent deformation is related to axial stent compression owing to extrinsic forces or secondary devices that disrupt stent architecture. Stent recoil occurs when a stent does not deploy at its optimal cross-sectional area. Tissue prolapse between stent struts may also predispose patients to adverse outcomes. Prevention, recognition, and treatment of these stent failures are necessary to optimize patient outcomes after percutaneous coronary interventions.

The role of angiographic follow-up after percutaneous coronary intervention

In the early days of coronary angioplasty, follow-up coronary angiography was often performed to assess restenosis. Angiographic restenosis has been shown to be associated with worse clinical outcomes, though the exact causality has yet to be determined. Numerous studies have repeatedly demonstrated that routine follow-up coronary angiography increases the incidence of target lesion revascularization without a clear reduction in mortality or myocardial infarction. Despite the lack of proven benefit of angiographic follow-up, routine follow-up coronary angiography is still being performed in certain countries and facilities. There are several factors that might explain the lack of benefit of angiographic follow-up: 1) lower incidence of stent failure in the current drug-eluting stent era has attenuated the net clinical benefit of follow-up angiography. 2) Angiographic restenosis might not lead to myocardial ischemia. 3) Patients that do have functionally significant restenosis are often referred for coronary angiography due to clinical indications such as intractable angina. 4) Absence of restenosis at the time of follow-up angiography does not exclude future restenosis. The absence of proven benefit in unselected populations does not necessarily preclude the presence of benefit in selected population, and there may be a subgroup of patients who can benefit from angiographic follow-up such as those with a large myocardial ischemic territory or those at very high risk of restenosis. Until there is more clinical evidence with respect to follow-up angiography, the decision of whether or not to perform it routinely in selected high-risk population should entail an in-depth discussion with the patient.

Multiple Stent Fractures After Everolimus-Eluting Stent Implantation Causing Acute Myocardial Infarction: A Case Report

Stent fracture is an uncommon complication of drug-eluting stent implantation, but it has a clinical significance because of its potential association with adverse cardiac events such as in-stent restenosis, target lesion revascularization, and stent thrombosis. Multiple stent fractures account for a small proportion, but they may lead to more serious complications. Newer generation drug-eluting stents are designed for improved safety and efficacy compared with early generation drug-eluting stents. Multiple stent fractures after newer generation drug-eluting stent implantation are a rare case.We report a case of 25-year-old male who presented with acute myocardial infarction caused by multiple stent fractures after everolimus-eluting stents implantation and was treated by balloon angioplasty.Physicians should be aware of the possibility of multiple stent fractures even after newer generation drug-eluting stent implantation.

Structural Mechanics Predictions Relating to Clinical Coronary Stent Fracture in a 5 Year Period in FDA MAUDE Database

Endovascular stents are the mainstay of interventional cardiovascular medicine. Technological advances have reduced biological and clinical complications but not mechanical failure. Stent strut fracture is increasingly recognized as of paramount clinical importance. Though consensus reigns that fractures can result from material fatigue, how fracture is induced and the mechanisms underlying its clinical sequelae remain ill-defined. In this study, strut fractures were identified in the prospectively maintained Food and Drug Administration's (FDA) Manufacturer and User Facility Device Experience Database (MAUDE), covering years 2006-2011, and differentiated based on specific coronary artery implantation site and device configuration. These data, and knowledge of the extent of dynamic arterial deformations obtained from patient CT images and published data, were used to define boundary conditions for 3D finite element models incorporating multimodal, multi-cycle deformation. The structural response for a range of stent designs and configurations was predicted by computational models and included estimation of maximum principal, minimum principal and equivalent plastic strains. Fatigue assessment was performed with Goodman diagrams and safe/unsafe regions defined for different stent designs. Von Mises stress and maximum principal strain increased with multimodal, fully reversed deformation. Spatial maps of unsafe locations corresponded to the identified locations of fracture in different coronary arteries in the clinical database. These findings, for the first time, provide insight into a potential link between patient adverse events and computational modeling of stent deformation. Understanding of the mechanical forces imposed under different implantation conditions may assist in rational design and optimal placement of these devices.

Stent Fracture After Sirolimus-Eluting Stent Implantation

Background—

Stent fracture (SF) after sirolimus-eluting stent implantation is reported to be associated with target lesion revascularization (TLR) and stent thrombosis. We aimed to assess the clinical impact of SF at 8 years.

Methods and Results—

Between 2002 and 2005, 972 patients (1795 lesions) underwent sirolimus-eluting stent implantation and follow-up angiography within 1 year after index procedure. SF, defined as the complete separation of stent segments or stent struts at follow-up angiography, was observed in 105 lesions (5.8%). The study sample comprised 954 patients (1630 lesions), excluding 147 lesions undergoing TLR and 18 patients (18 lesions) who died or in whom stent thrombosis developed within 1 year after sirolimus-eluting stent implantation. The median follow-up duration was 9.1 years (the first and third quarters, 8.7 and 9.4 years). The primary end point was defined as any TLR. The 8-year cumulative rates of adverse events were estimated by Kaplan–Meier methods with P values from log-rank tests. Between patients with and without SF, there were no significant differences in the cumulative rates of all-cause death (23.5% versus 27.6%, P =0.35) and cardiac death (4.7% versus 9.1%, P =0.14), whereas patients with SF had significantly higher cumulative rates in myocardial infarction (10.1% versus 3.3%, P =0.001), very late stent thrombosis (6.8% versus 0.7%, P <0.001), any TLR (38.1% versus 10.8%, P <0.001), and clinically driven TLR (26.2% versus 6.6%, P <0.001).

Conclusions—

SF after sirolimus-eluting stent implantation was consistently associated with higher rates of adverse cardiac events during the 8-year follow-up.

Mechanical complications of everolimus-eluting stents associated with adverse events: an intravascular ultrasound study

AIMS

Mechanical complications contribute to bare metal and first-generation drug-eluting stent (DES) failure. However, the importance of the mechanical complications of second-generation DES remains unclear. We report mechanical complications associated with everolimus-eluting stent (EES) failures.

METHODS AND RESULTS

We retrospectively analysed 177 consecutive EES-treated lesions in 136 patients who underwent intravascular ultrasound (IVUS) at follow-up. Mechanical complications were identified in 17 patients (five stable angina, 10 unstable angina, two non-ST-elevation myocardial infarction [NSTEMI] without angiographic thrombus). Fifteen (88.2%) were treated with repeat revascularisation. By IVUS, there were 16 focal (94.1%) and one diffuse (5.9%) in-stent restenoses. Complete stent fracture with separation was seen in only one, partial stent fracture with separation was seen in three, and in 13 there was longitudinal deformation (n=2) or stent strut fracture (n=11) with overlapping of the proximal and distal stent fragments. In 13 EES with evidence of overlapping in the setting of either fracture or deformation, there was a 35.5±12.2% smaller stent area compared to the adjacent proximal and distal stent fragments, and >50% neointimal hyperplasia in 12 (92.3%).

CONCLUSIONS

We found EES mechanical complications, often followed by longitudinal deformation or fracture leading to excessive neointimal hyperplasia, in-stent restenosis, and repeat revascularisation.

Coronary stent fracture: a recently appreciated phenomenon with clinical relevance

In the stent era, in addition to restenosis, there are many important consequences deserving more attention. Firstly described in peripheral vascular interventions, it took several years for stent fracture to be known as an appreciable complication of coronary intervention. Especially with the introduction of drug eluting stents and the use of coronary stents in more complex cases, its prevalence has raised and new data have been published concerning its mechanism, predictors, diagnosis, clinical course and treatments. This review will discuss the available literature about stent fracture.

Incidence and clinical impact of stent fracture after the Nobori biolimus-eluting stent implantation

Background

Stent fracture (SF) after drug‐eluting stent implantation has become an important concern. The aim of this study was to assess the incidence, predictors, and clinical impact of SF after biolimus‐eluting stent.

Methods and Results

A total of 1026 patients with 1407 lesions undergoing the Nobori biolimus‐eluting stent implantation and follow‐up angiography within 9 months after index procedure were analyzed. SF was defined as complete or partial separation of the stent, as assessed by using plain fluoroscopy, intravascular ultrasound, or optical coherence tomography during the follow‐up. We assessed the rate of SF and the cumulative incidence of clinically driven target lesion revascularization and definite stent thrombosis within 9 months. SF was observed in 58 (4.1%) of 1407 lesions and 57 (5.5%) of 1026 patients. Lesions with hinge motion (OR 8.90, 95% CI 3.84 to 20.6, P<0.001), tortuosity (OR 4.16, 95% CI 1.75 to 9.88, P=0.001), and overlapping stents (OR 2.41, 95% CI 0.95 to 6.10, P=0.06) were predictors of SF. Cumulative incidence of clinically driven target lesion revascularization within 9 months was numerically higher in the SF group than that in the non‐SF group (12.0% versus 1.0%). Cumulative incidence of definite stent thrombosis within 9 months tended to be higher in the SF group than that in the non‐SF group (1.7% versus 0.5%).

Conclusions

SF after biolimus‐eluting stent occurs in 4.1% of lesions and appears to be associated with clinically driven target lesion revascularization.

Incidence and clinical impact of stent fracture after everolimus-eluting stent implantation

BACKGROUND

Stent fracture (SF) after drug-eluting stent implantation has recently become an important concern because of its potential association with in-stent restenosis and stent thrombosis. However, the incidence and clinical impact of SF after everolimus-eluting stent implantation remain unclear.

METHODS AND RESULTS

A total of 1035 patients with 1339 lesions undergoing everolimus-eluting stent implantation and follow-up angiography 6 to 9 months after index procedure were analyzed. SF was defined as complete or partial separation of the stent, as assessed by plain fluoroscopy or intravascular ultrasound during follow-up. We assessed the rates of SF and major adverse cardiac events, defined as cardiac death, myocardial infarction, stent thrombosis, and clinically driven target lesion revascularization within 9 months. SF was observed in 39 of 1339 lesions (2.9%) and in 39 of 1035 patients (3.8%). Ostial stent location and lesions with hinge motion, tortuosity, or calcification were independent predictors of SF. The rate of myocardial infarction and target lesion revascularization were significantly higher in the SF group than in the non-SF group (5.1% versus 0.4%; P=0.018 and 25.6% versus 2.0%; P<0.001, respectively). Stent thrombosis was more frequently observed in the SF group than in the non-SF group (5.1% versus 0.4%; P=0.018). Major adverse cardiac events within 9 months were significantly higher in the SF group than in the non-SF group (25.6% versus 2.3%; P<0.001).

CONCLUSIONS

SF after everolimus-eluting stent implantation occurs in 2.9% of lesions and is associated with higher rate of major adverse cardiac events, driven by higher target lesion revascularization and stent thrombosis.