Clinical and angiographic outcomes with sirolimus-eluting stents in total coronary occlusions: the ACROSS/TOSCA-4 (Approaches to Chronic Occlusions With Sirolimus-Eluting Stents/Total Occlusion Study of Coronary Arteries-4) trial

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].

Five-year clinical outcomes of zotarolimus-eluting stents in coronary total occlusions

AIMS

Reports of long-term outcomes of patients treated with drug-eluting stents in total coronary occlusions are limited. We analysed clinical outcomes of patients treated with the zotarolimus-eluting Resolute stent (R-ZES) implanted in coronary total occlusions versus non-occluded lesions.

METHODS AND RESULTS

Patients treated with R-ZES and included in four trials (RESOLUTE All Comers, RESOLUTE International, RESOLUTE China RCT, and RESOLUTE China Registry) were pooled and divided into three groups - patients with chronic total occlusions (CTO), patients with total occlusions that had occurred recently (rec-TO), and patients without total occlusions (non-TO). Clinical outcomes at five years were analysed. Of 5,487 patients treated with R-ZES in these trials, 8.0% had CTOs, 8.5% rec-TOs and 83.5% non-TOs. Patients had a mean age of 62.8 years, approximately 25% were female and 30% were diabetics. TLF was similar in the three groups at five years (TLF was 13.2%, 12.5% and 13.3% in the CTO, rec-TO and non-TO groups, respectively, p=0.96). Stent thrombosis tended to occur more frequently for rec-TO compared to CTO and non-TO patients (2.6% vs 1.2% and 1.3%, respectively, p=0.11).

CONCLUSIONS

In this large population of patients who had R-ZES implanted, five-year clinical outcomes were similar whether or not the stents were implanted in total occlusions.

The Canadian Contribution to Science, Techniques, Technology, and Education in Chronic Total Occlusion Percutaneous Coronary Intervention

Chronic total occlusions are considered the most complex coronary lesions in interventional cardiology. This article reviews the Canadian clinical and academic contributions to this field, including innovative procedural techniques, teaching and proctoring, clinical research, and the development of novel tools and therapies.

Long-term outcomes of medical therapy versus successful recanalisation for coronary chronic total occlusions in patients with and without type 2 diabetes mellitus

Background

In this study, we compared the outcomes of medical therapy (MT) with successful percutaneous coronary intervention (PCI) in chronic total occlusions (CTO) patients with and without type 2 diabetes mellitus.

Methods

A total of 2015 patients with CTOs were stratified. Diabetic patients (n = 755, 37.5%) and non-diabetic patients (n = 1260, 62.5%) were subjected to medical therapy or successful CTO-PCI. We performed a propensity score matching (PSM) to balance the baseline characteristics. A comparison of the major adverse cardiac events (MACE) was done to evaluate long-term outcomes.

Results

The median follow-up duration was 2.6 years. Through multivariate analysis, the incidence of MACE was significantly higher among diabetic patients compared to the non-diabetic patients (adjusted hazard ratio [HR] 1.32, 95% confidence interval [CI] 1.09–1.61, p = 0.005). Among the diabetic group, the rate of MACE (adjusted HR 0.61, 95% CI 0.42–0.87, p = 0.006) was significantly lower in the successful CTO-PCI group than in the MT group. Besides, in the non-diabetic group, the prevalence of MACE (adjusted HR 0.85, 95% CI 0.64–1.15, p = 0.294) and cardiac death (adjusted HR 0.94, 95% CI 0.51–1.70, p = 0.825) were comparable between the two groups. Similar results as with the early detection were obtained in propensity-matched diabetic and non-diabetic patients. Notably, there was a significant interaction between diabetic or non-diabetic with the therapeutic strategy on MACE (p for interaction = 0.036).

Conclusions

For treatment of CTO, successful CTO-PCI highly reduces the risk of MACE in diabetic patients when compared with medical therapy. However, this does not apply to non-diabetic patients.

Late-term safety and effectiveness of everolimus-eluting stents in chronic total coronary occlusion revascularization: Final 4-year results from the evaluation of the XIENCE coronary stent, Performance, and Technique in Chronic Total Occlusions (EXPERT CTO) multicenter trial

BACKGROUND

Limited study has detailed the late-term safety and efficacy of chronic total coronary occlusion (CTO) revascularization among multiple centers applying modern techniques and with newer-generation drug-eluting stents.

METHODS

Among 20 centers, 222 patients enrolled in the XIENCE coronary stent, performance, and technique (EXPERT) CTO trial underwent CTO percutaneous coronary intervention (PCI) with everolimus-eluting stents (EES). Through planned 4-year follow-up, the primary composite endpoint of major adverse cardiac events (MACE; death, myocardial infarction [MI] and target lesion revascularization) and rates of individual component endpoints and stent thrombosis were determined.

RESULTS

Demographic, lesion, and procedural characteristics included prior bypass surgery, 9.9%; diabetes, 40.1%; lesion length, 36.1 ± 18.5 mm; and stent length, 51.7 ± 27.2 mm. By 4 years, MACE rates were 31.6 and 22.4% by the pre-specified ARC and per-protocol definitions, respectively. Clinically-indicated target lesion revascularization at 4 years was 11.3%. In landmark analyses of events beyond the first year of revascularization, the annualized rates of target vessel-related MI and clinically-indicated target lesion revascularization were 0.53 and 1.3%, respectively. Through 4 years, the cumulative definite/probable stent thrombosis rate was 1.7% with no events occurring beyond the initial year of index revascularization.

CONCLUSIONS

In a multicenter registration trial representing contemporary technique and EES, these results demonstrate sustained long-term safety and effectiveness of EES in CTO percutaneous revascularization and can be used to inform shared decision making with patients being considered for CTO PCI relative to late safety and vessel patency.

Bioresorbable vascular scaffolds in coronary chronic total occlusions revascularization: safety assessment related to struts coverage and apposition in 6-month OCT follow-up

Beneficial properties of bioresorbable vascular scaffolds (BVS) regarding to vasomotility restoration and no caging of the vessel make them attractive devices in chronic total occlusions (CTO) revascularization. However, more evidence is needed attending to their use in this specific setting. We aim to determine feasibility and safety of BVS use in CTO revascularization attending to struts coverage and apposition, as well as re-stenosis and stent thrombosis (ST) rates. 29 BVS were deployed in 9 CTO lesions revascularization (mean J-CTO score ≥3) with an acute procedural success rate of 100%. Clinical and angiographic follow-up was performed 6 months later, including intracoronary analyses from optical coherence tomography (OCT) images. 44,723 struts were analyzed within the total 636 mm of scaffolded vessel. Mean length scaffolded per lesion was 70.66 ± 31.01 mm with a mean number of 3.22 BVS. 2051 struts (4.59%) were identified as uncovered, being most of them (98.4%) neither malapposed nor disrupted. Mean thickness of struts' coverage was 0.13 ± 0.05 mm. Incomplete strut apposition (ISA) percentage was 0% as no malapposed struts were detected and 134 struts were identified as disrupted, which represents a 0.29% from the total. Mean vessel, scaffold, and lumen diameters were 3.87 ± 0.51, 2.97 ± 0.49, and 2.68 ± 0.50 mm, respectively. Neither in-stent re-stenosis nor ST was detected. During follow-up, none of our patients died, suffered from stroke or needed target lesion revascularization. Clinical and angiographic 6-month follow-up (including OCT analyses) of BVS in CTO revascularization suggests their effectiveness and safety, even in very complex chronic occluded lesions. Nevertheless, more evidence is needed.

Influence about the flow of distal branch after intervention of the right coronary artery chronic total occlusion

OBJECTIVE

Limited data are available for the clinical outcomes after the recanalization of right coronary artery (RCA) chronic total occlusion (CTO). The study aims to assess the clinical outcomes in the antegrade flow of the distal branch after successful RCA CTO percutaneous coronary intervention (PCI).

METHODS

Between January 2002 and December 2012, 538 patients who underwent RCA CTO PCI were enrolled. The clinical outcomes as myocardial infarction (MI), target vessel revascularization, cardiac death, major adverse cardiac events, and all-cause mortality, were compared to the antegrade flow of distal branch after successful RCA CTO PCI.

RESULTS

The CTOs were located in proximal segments (57.6%), mid segments (27.5%) and distal segments (14.9%). The average Syntax score was 18.4±9.6 and 47.8% patients had a Syntax score greater than 27.5. A total of 62.8% patients had final thrombolysis of myocardial infarction (TIMI)-3 flow of distal branch, 16.9% patients had final TIMI-3 flow of only one major branch, 11.3% patients had TIMI-1-2 flow, and 8.9% patients had no antegrade flow. The incidence of periprocedural MI was lower in both side branches were preserved (13.9% vs. 23.0% and 18.8%, p=0.01). The clinical outcomes were similar between the groups with and without good antegrade flow of distal side branch. End stage renal disease (ESRD) and left ventricular ejection fraction (LVEF) <40% predicted three-year cardiac death.

CONCLUSIONS

There is no significant difference of clinical outcomes when distal side branches of RCA are recanalized successfully. ESRD and LVEF <40% were the predictors for three-year cardiac death.

Application of a snare technique in retrograde chronic total occlusion percutaneous coronary intervention - a step by step practical approach and an observational study

Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has recently become popular among interventional cardiologists. CTO originating from the ostium has been one of the most difficult CTO lesions to treat with PCI for a number of reasons. Our aim was to illustrate a specific technique during retrograde CTO PCI referred to as the "snare technique."We retrospectively examined the use of "snare technique" among 371 consecutive retrograde CTO PCIs performed at our institution between 2006 and 2015."Snare technique" was used in 10 patients among the 371 retrograde CTO PCIs. The baseline clinical and angiographic characteristics of patients with or without "snare technique" were similar. The "snare technique" group had significantly fewer side branches at occlusion (30.0% vs 71.2%, P = 0.01) and a higher incidence of externalization (90% vs 25.5%, P < 0.001). The contrast volume was significantly lower in the "snare technique" group (285.0 ± 68.5 vs 379.2 ± 144.0, P = 0.04). The incidence of major complications, retrograde success, or final success did not differ between the groups.The "snare technique" is safe and feasible in retrograde CTO PCI, especially in cases of difficult coronary engagement in cases such as ostial occlusion, challenging coronary anatomy, or retrograde guidewire cannot get in antegrade guiding catheter.

Comparison of 12-month clinical outcomes in diabetic and nondiabetic patients with chronic total occlusion lesions: a multicenter study

Supplemental Digital Content is available in the text.

This study aimed to compare 1-year clinical outcomes in diabetic and nondiabetic patients with chronic total occlusion (CTO) lesions.

Percutaneous Treatment of Coronary Chronic Total Occlusions Part 1: Rationale and Outcomes

Coronary chronic total occlusions (CTOs) are commonly encountered in patients with coronary artery disease. Compared to patients without coronary CTOs, those with CTO have worse clinical outcomes and lower likelihood of complete coronary revascularisation. Successful CTO percutaneous coronary intervention (PCI) can significantly improve angina and improve left ventricular function. Although currently unproven, successful CTO PCI might also reduce the risk for arrhythmic events in patients with ischaemic cardiomyopathy, provide better tolerance of future acute coronary syndrome, and possibly improve survival. Evaluation by a heart team comprised of both interventional and non-interventional cardiologists and cardiac surgeons is important for determining the optimal revascularisation strategy in patients with coronary artery disease and CTOs. Ad hoc CTO PCI is generally not recommended, so as to allow sufficient time for (a) discussion with the patient about the indications, goals, risks, and alternatives to PCI; (b) careful procedural planning; and (c) contrast and radiation exposure minimisation. Use of drug-eluting stents is recommended for CTO PCI, given the lower rates of angiographic restenosis compared to bare metal stents.

Late catch-up in lumen diameter at five-year angiography in MACE-free patients treated with sirolimus-eluting stents in the Primary Stenting of Totally Occluded Native Coronary Arteries: a randomised comparison of bare metal stent implantation with sirolimus-eluting stent implantation for the treatment of total coronary occlusions (PRISON II)

AIMS

The present study was designed to examine the five-year angiographic follow-up of MACE-free patients enrolled in the PRISON II study.

METHODS AND RESULTS

In the PRISON II study a total of 200 patients were randomised to either bare metal stents (BMS) or sirolimus-eluting stents (SES) after successful recanalisation of total coronary occlusions (TCO). Patients free of MACE with available angiography at six months were approached for repeated angiography at five years. The primary endpoint was in-stent very late luminal loss (VLLL) at five years. The secondary endpoint was additional late luminal loss (ALLL) between six months and five years. At five years, repeated angiography was performed in 72 patients, 50/82 (61%) in the SES group and 22/58 (38%) in the BMS group. In-stent VLLL was lower in the SES group (0.19 mm ± 0.72 vs. 0.51 mm ± 0.71, p=0.09) compared to the BMS group and in-segment VLLL was comparable in both groups (0.01 mm±0.58 vs. 0.03 mm ± 0.73, p=0.89). Late catch-up in lumen diameter was observed in the SES group with a trend towards increased ALLL compared to the BMS group (in-stent, 0.35 mm ± 0.88 vs. 0.04 mm ± 0.81, p=0.16; in-segment, 0.20 mm ± 0.74 vs. -0.05 mm ± 0.73, p=0.19).

CONCLUSIONS

At five-year angiographic follow-up, late catch-up was observed after successful recanalisation of TCOs treated with SES. Despite a late catch-up, the angiographic results of SES were superior in-stent and similar in-segment compared to BMS.

Stent fracture: how frequently is it recognized?

In spite of there being several case reports, coronary stent fracture is not a well-recognized entity and incidence rates are likely to be underestimated. In this article, we review different aspects of stent fracture, including incidence, classification, predictors, outcome, diagnosis, and management.

Efficacy and safety of sirolimus-eluting stents versus bare-metal stents in coronary artery disease patients with diabetes: a meta-analysis

OBJECTIVE

To compare by meta-analysis the efficacy and safety of sirolimus-eluting and bare-metal stents in coronary artery disease (CAD) patients with diabetes.

METHOD

PubMed, MEDLINE and EMBASE were searched from 1971 to 2012. Data on the efficacy and safety of sirolimus-eluting and bare-metal stents in patients with diabetes were collected. A meta-analysis was then performed on a total of 1 259 CAD patients with diabetes from six studies. The odds ratio (OR) was used for comparison. Subgroup analysis was performed according to the sample size, year of study, subjects' geographic area and study method.

RESULTS

Compared with those in the bare-metal stent group (BMS), the subjects in the sirolimus-eluting stent (SES) group had a reduced risk for major cardiac events [OR 0.42, 95% confidence interval (CI): 024-0.74, p < 0.01] and target-lesion revascularisation (OR 0.26, 95% CI: 0.11 - 0.59, p < 0.01). There was no difference for myocardial infarction (OR 0.92, 95% CI: 0.61-1.40, p > 0.05) or mortality (OR 1.19, 95% CI: 0.74-1.92, p > 0.05). Subgroup analysis showed a significant difference for overall risk of major cardiac events between SES and BMS when the sample size was ≤ 90 (OR 0.28, 95% CI: 0.16-0.48, p < 0.01), when it was a randomised control trial (RCT) (OR 0.28, 95% CI: 0.19-0.42, p < 0.01), or when it was performed on European subjects (OR 0.45, 95% CI: 0.27-0.77, p < 0.01). The sensitivity was not different when one study was removed at a time.

CONCLUSION

Our study confirmed that SES are safer and more effective than BMS in CAD patients with diabetes, as far as major cardiac events are concerned.

A completely fractured zotarolimus-eluting stent in an aortocoronary saphenous vein bypass graft

Drug-eluting stents (DES) have significantly improved the rate of target vessel revascularization in comparison with bare metal stents. DES fracture was not reported in multicenter randomized clinical trials, but several case reports of DES fracture have been published, mostly with sirolimus-eluting stents. DES fracture is associated with stent restenosis and thrombosis. We report a zotarolimus-eluting stent fracture in an aortocoronary saphenous vein graft (SVG) bypass. The patient presented with chest pain and a non-ST-elevation myocardial infarction. He underwent cardiac catheterization that showed a complete fracture of a zotarolimus-eluting stent in the ostium of a sequential SVG to the diagonal and obtuse coronary arteries. His management included coronary angioplasty and retrieval of the proximal fractured segment. We discuss the potential causes for this stent fracture and suggest caution when using a DES in an ostial location of a SVG bypass, especially in a highly mobile vessel.

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.

Collagenase Total Occlusion-1 (CTO-1) trial: a phase I, dose-escalation, safety study

BACKGROUND

Percutaneous interventions for chronic total occlusions have low success rates, primarily because of failure of guide wire crossing. Collagen-rich matrix constitutes the main barrier to chronic total occlusion crossing. In preclinical studies, local delivery of a bacterial collagenase formulation improved guide wire crossing. The Collagenase Total Occlusion-1 (CTO-1) Trial is a phase I, dose-escalation trial to assess the safety and efficacy of collagenase therapy to facilitate guide wire crossing in coronary artery chronic occlusions.

METHODS AND RESULTS

Twenty subjects with ≥1 previous failure of chronic total occlusion guide wire crossing were enrolled at 2 sites. Subjects were treated in 4 distinct cohorts of 5 patients, with escalation of collagenase dose in each cohort from 300 to 1200 μg. Collagenase was locally delivered into the occlusions with either an over-the-wire balloon system (n=8) or a fine-cross microcatheter (n=12) for a period of 30 minutes. Subjects were brought back to the catheterization laboratory for guide wire crossing and angioplasty the next day. Guide wire crossing was successfully achieved in 15 subjects (75%). A soft-tip guide wire (Whisper, Pilot-50, Fielder XT) was either the sole or predominant guide wire used in 75% of successful crossings. Non-ST-segment-elevation myocardial infarctions occurred in 3 patients as a result of side-branch ischemia during stenting. Computed tomographic angiography at 3 months showed no late complications and patent stents in successfully treated chronic total occlusion. Anginal improvement occurred with a reduction in Canadian Cardiovascular Society class from baseline to 3 months (2.5±0.6 versus 0.9±0.9; P<0.001).

CONCLUSION

Local delivery of collagenase into coronary chronic total occlusion is feasible and safe with encouraging guide wire crossing results in previously failed cases. Larger clinical trials are required to determine efficacy.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01271335.

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

Background—

Although stent fracture (SF) after sirolimus-eluting stent (SES) implantation has been recognized as one of the predisposing factors of in-stent restenosis, it remains uncertain whether SF can increase the risk of major adverse cardiac events (MACE), especially beyond 1 year after SES implantation. The aim of this study was to assess the impact of SF relative to non-SF on 4-year clinical outcomes after treatment with SES of comparable unselected lesions.

Methods and Results—

A total of 874 lesions in 793 patients undergoing SES implantation and subsequent angiography 6 to 9 months after index procedure were analyzed. At 6- to 9-month angiographic follow-up, SF was identified in 70 of 874 lesions (8.0%). In-stent late loss was significantly higher in SF lesions versus non-SF lesions (0.42±0.59 mm versus 0.13±0.49 mm, P <0.001), resulting in a significantly higher in-stent restenosis rate (21.4% versus 4.1%, P <0.001). At 4 years, SF versus non-SF was associated with a significantly higher MACE rate (23.2% versus 12.6%, P =0.014), mainly driven by significantly higher target-lesion revascularization (18.8% versus 10.2%, P =0.029) rate. Adverse effects of SF on clinical outcomes occurred mostly within the first year (17.4% versus 6.6%, P =0.001), with similar MACE rate between 1 and 4 years (5.8% versus 5.9%, P =0.611). No significant differences between SF versus non-SF patients were observed in the cumulative frequency of very late stent thrombosis (2.9% versus 1.4%, P =0.281), death (0% versus 2.1%, P =0.252), or myocardial infarction (5.8% versus 2.9%, P =0.165).

Conclusions—

SF of SES was associated with higher MACE rate up to 1 year, mainly driven by higher target-lesion revascularization, whereas no significant association was evident between years 1 and 4.

Predicting successful guidewire crossing through chronic total occlusion of native coronary lesions within 30 minutes: the J-CTO (Multicenter CTO Registry in Japan) score as a difficulty grading and time assessment tool

OBJECTIVES

This study sought to establish a model for grading lesion difficulty in interventional chronic total occlusion (CTO) treatment.

BACKGROUND

Owing to uncertainty of success of the procedure and difficulties in selecting suitable cases for treatment, performance of interventional CTO remains infrequent.

METHODS

Data from 494 native CTO lesions were analyzed. To eliminate operator bias, the objective parameter of successful guidewire crossing within 30 min was set as an end point, instead of actual procedural success. All observations were randomly assigned to a derivation set and a validation set at a 2:1 ratio. The J-CTO (Multicenter CTO Registry of Japan) score was determined by assigning 1 point for each independent predictor of this end point and summing all points accrued. This value was then used to develop a model stratifying all lesions into 4 difficulty groups: easy (J-CTO score of 0), intermediate (score of 1), difficult (score of 2), and very difficult (score of ≥ 3).

RESULTS

The set end point was achieved in 48.2% of lesions. Independent predictors included calcification, bending, blunt stump, occlusion length >20 mm, and previously failed lesion. Easy, intermediate, difficult, and very difficult groups, stratified by J-CTO score, demonstrated stepwise, proportioned, and highly reproducible differences in probability of successful guidewire crossing within 30 min (87.7%, 67.1%, 42.4%, and 10.0% in the derivation set and 92.3%, 58.3%, 34.8%, and 22.2% in the validation set, respectively). Areas under receiver-operator characteristic curves were comparable (derivation: 0.82 vs. validation: 0.76).

CONCLUSIONS

This model predicted the probability of successful guidewire crossing within 30 min very well and can be applied for difficulty grading.

Drug-eluting stents for coronary artery disease: a review

Over the past decade the introduction of drug-eluting stents (DESs) has revolutionised the treatment of coronary artery disease. However, in recent years concern has arisen over the long-term safety and efficacy of DESs due to the occurrence of late adverse clinical events such as stent thrombosis. With this concern in mind, research and development is currently centred on increasing the long-term safety and efficacy of DESs. The aim of this paper is to provide a thorough review of currently approved and promising investigational DESs. With dozens of companies involved in the development of new and innovative anti-restenotic agents, polymeric coatings and stent platforms, it is intended that this review paper will provide a clear indication of how DESs are currently evolving and prove a valuable reference tool for future research in this area.

Stent fracture after everolimus-eluting stent implantation

Compared with bare-metal stents, drug-eluting stents (DES) have greatly reduced the risk of in-stent restenosis (ISR) by inhibiting neointimal growth. Nevertheless, DES are still prone to device failure, which may lead to cardiac events. Recently, stent fracture (SF) has emerged as a potential mechanism of DES failure that is associated with ISR. Stent fracture is strongly related to stent type, and prior reports suggest that deployment of sirolimus eluting stents (SES) may be associated with a higher risk of SF compared to other DES. Everolimus eluting stents (EESs) represent a new generation of DES with promising results. The occurrence of SF with EES has not been well established. The present paper describes two cases of EES fracture associated with ISR.

Recurrent episodes of very late stent thrombosis in a patient with aspirin hypersensitivity, stent fracture and malapposition

Late stent thrombosis represents a life-threatening event, usually triggered by inadequate antiplatelet therapy and promoted by multiple risk factors, such as stenting of a chronic total occlusion, overlapping stenting, an abnormal vascular response to the eluted drug, stent malapposition and stent fracture. A 57-year-old man with aspirin hypersensitivity underwent successful percutaneous revascularization of a chronic total occlusion of the left anterior descending artery (LAD). He received two sirolimus-eluting stents overlapping for 2 mm and was discharged on clopidogrel and picotamide. Two years later, 15 days after clopidogrel discontinuation, he experienced an anterior ST-segment elevation myocardial infarction and underwent rescue percutaneous LAD thrombectomy after unsuccessful fibrinolysis. Coronary angiography showed fracture of the distal stent, with a 5 mm gap between the two portions, as well as severe late stent malapposition, confirmed by optical coherence tomography. Despite treatment with clopidogrel and picotamide, in the following days the patient experienced two new episodes of stent thrombosis, treated with thrombectomy and deployment of bioengineered stents. The patient underwent successful oral aspirin desensitization, with a complete in vitro inhibition of platelet function, and was discharged on aspirin, clopidogrel and warfarin, without experiencing other events at 6-month follow-up.

Late catch-up phenomenon associated with stent fracture after sirolimus-eluting stent implantation: incidence and outcome

OBJECTIVE

To examine the long-term outcome of the stent fracture (SF) and the potential predictive factors contributing to in-stent restenosis (ISR) in the fractured stent.

BACKGROUND

The SF is thought to be a higher risk of ISR in drug-eluting stent, although SF does not always develop ISR.

METHODS

The consecutive 1,228 de novo lesions in 1,079 patients who underwent sirolimus-eluting stents implantation and assessed by 8 months follow-up coronary angiography were retrospectively analyzed.

RESULTS

One hundred and seventeen SFs (9.5%) were identified in 100 patients and 22 (18.8%) SFs revealed ISR at the first follow-up. In addition, 16 (13.7%) developed new ISRs from 95 residual SFs without ISR prior to the second follow-up. Overall, 38 (32.5%) of all 117 SFs developed ISR, and 16 (42.1%) of 38 SFs occurred in a late phase beyond the first 8 months follow-up. A higher risk of ISR in the SF site was associated with the chronic total occlusion (ISR vs. no ISR: 34.2% vs. 16.5%, P = 0.0304), calcified lesions (55.3% vs. 34.2%, P = 0.0299), and correspondence 89.5% versus 43.0%, P < 0.0001 (SF site occurring at the original target lesion site) in the univariate analysis. The correspondence was identified as the only strong predictive factor for ISR at the SF site according to a multivariate logistic regression analysis (odds ratio 12.6, 95% confidence interval 3.82-53.5, P < 0.0001).

CONCLUSIONS

SF occurring at the site of the original target lesion was a strong independent predictor of ISR. This indicates the need for a careful, long-term follow-up in those situations, even when no significant ISR is initially detected.