Stent Fracture After Sirolimus-Eluting Stent Implantation

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].

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.

Impact of Dual Antiplatelet Therapy Beyond 1 Year on Clinical Outcomes of Patients With Stent Fracture or Peri-Stent Contrast Staining After Sirolimus-Eluting Stent Implantation

BACKGROUND

Stent fracture (SF) and peri-stent contrast staining (PSS) after sirolimus-eluting stent (SES) implantation are considered to be related to very late stent thrombosis (VLST). How dual antiplatelet therapy (DAPT) beyond 1 year affects the clinical outcomes of patients with SF or PSS remains unclear.Methods and Results:Based on their DAPT status, 1,962 patients undergoing SES implantation were classified as on-thienopyridine (n=1,404) or off-thienopyridine (n=558). The 6-year incidence of VLST was significantly lower in the on-thienopyridine patients (0.56% vs. 1.8%, P=0.01), whereas cardiac death and myocardial infarction (MI) were similar (5.0% vs. 6.2%, P=0.31; 3.2% vs. 4.0%, P=0.33; respectively). The 1,962 patients were also classified as having SF/PSS (n=256) or non-SF/PSS (n=1,706). In the SF/PSS group, VLST and MI were significantly lower in on-thienopyridine patients (1.9% vs. 10.1%, P=0.003; 3.5% vs. 10.3%, P=0.02; respectively). In the non-SF/PSS group, VLST and MI were similar (0.36% vs. 0.45%, P=0.78; 3.2% vs. 3.0%, P=0.93; respectively). In both groups, cardiac death was similar (3.6% vs. 4.3%, P=0.78; 5.2% vs. 6.5%, P=0.32; respectively).

CONCLUSIONS

Prolonged DAPT was associated with significantly lower incidences of VLST and MI in the SF/PSS group, but had no effect on cardiac death, VLST, or MI in the non-SF/PSS group.

Stent Fracture and Peri-Stent Contrast Staining After Everolimus-Eluting Stent Implantation - 5-Year Outcomes

BACKGROUND

Stent fracture (SF) and peri-stent contrast staining (PSS) after sirolimus-eluting stent implantation are reported to be risk factors of adverse events. However, the effect of these after everolimus-eluting stent (EES) implantation on long-term outcomes remains unclear.Methods and Results:The study sample comprised 636 patients (1,081 lesions) undergoing EES implantation in 2010 and follow-up angiography within 1 year. The 5-year cumulative rates of target lesion revascularization (TLR) and major adverse cardiac events (MACE: a combination of all-cause death, myocardial infarction, and TLR) were compared between patients with and without SF or PSS. SF was observed in 2.7%, and PSS in 3.0%. The cumulative rates of MACE and TLR were significantly higher in the SF group than in the non-SF group (51.7% vs. 27.5% and 48.3% vs. 13.4%, respectively), but showed no significant differences between the PSS and non-PSS groups. In a landmark analysis, the rate of TLR within 1 year was significantly higher in the SF group than in the non-SF group (44.8% vs. 7.2%), but beyond 1 year showed no significant difference (6.3% vs 6.7%).

CONCLUSIONS

The 5-year clinical outcomes suggested that SF after EES implantation is related to increased risk of MACE and TLR, especially within 1 year after the procedure, but PSS after EES implantation is unrelated.

Incidence and Long-Term Clinical Impact of Late-Acquired Stent Fracture After Sirolimus-Eluting Stent Implantation in Narrowed Coronary Arteries

The incidence and long-term clinical impact of stent fracture (SF) occurred beyond 1 year after sirolimus-eluting stent (SES) implantation remains unclear. From April 2004 to March 2008, 985 consecutive patients with 1,307 lesions were treated only with SES. Of these, 868 patients (88.1%) with 1,140 lesions underwent follow-up angiography within 1 year after the index procedure, and 646 patients (65.6%) with 872 lesions underwent it both within and beyond 1 year after the index procedure. According to the diagnosed timing of SF, we divided the patients into the 2 groups: early SF (<1 year after the index procedure) and late-acquired SF (>1 year after the index procedure). Early- and late-acquired SFs were observed in 64 of 868 patients (7.4%) and 66 of 1,140 lesions (5.8%); 12 of 646 patients (1.9%) and 12 of 872 lesions (1.4%), respectively. Cumulative 10-year incidence of clinically driven target lesion revascularization and definite stent thrombosis were numerically higher in the early- and late-acquired SF groups than in the non-SF group (41.6% vs 45.5% vs 19.0%; 8.0% vs 8.3% vs 2.0%, respectively). In conclusion, late-acquired SF after SES implantation occurred in 1.4% of lesions, which was lower than that of early SF. However, both early- and late-acquired SFs appeared to be associated with clinically driven target lesion revascularization and stent thrombosis during the long-term follow-up.

Everolimus eluting stent vs first generation drug-eluting stent in primary angioplasty: A pooled patient-level meta-analysis of randomized trials

BACKGROUND

Several concerns have emerged about the higher risk of very late stent thrombosis (ST) with first generation drug-eluting stent (DES) especially among STEMI patients. Newer generation DES has demonstrated to reduce ST at mid-term follow-up. Therefore, the aim of the present study is to perform an individual patient's data meta-analysis of trials comparing 1st generation DES vs. 2nd generation DES (everolimus-eluting stent, EES) in patients undergoing primary percutaneous coronary intervention (PCI) for STEMI.

METHODS

We performed a formal search of electronic databases (MEDLINE and CENTRAL) and scientific session presentations from January 2010 to June 2016. We included all completed randomized trials comparing 1st vs. EES for patient presenting with STEMI.

RESULTS

Individual patients data were obtained from 3 trials, including a total of 1581 patients (686 or 43.4% randomized to 1st generation DES and 895 or 56.4% randomized to EES). At long-term follow-up (1584±588days), EES did not significantly reduce mortality (7.8.% vs 11.7%, HR [95%CI]=0.77 [0.52, 1.13], p=0.18, p_{heterogeneity}=0.93), cardiac mortality (6.2% vs 7.6%, HR [95%CI]=0.90 [0.56, 1.44], p=0.65, p_{heterogeneity}=0.85), and reinfarction (8.1% versus 11.2%, respectively; HR [95%CI]=0.74 [0.51, 1.07], p=0.11, p_{heterogeneity}=0.52). However, EES significantly reduced the occurrence of ST (3.4% versus 6.1% respectively, HR [95%CI]=0.56 [0.32, 0.97], p=0.04, p_{heterogeneity}=0.42) and target vessel revascularization (TVR) (14.2% versus 20.1%; HR [95%CI]=0.63 [0.42, 0.96], p=0.03, p_{heterogeneity}=0.55). Landmark analysis showed more consistent benefits in ST with EES within 1year, whereas benefits in TVR were mostly observed later than 1year.

CONCLUSIONS

The present pooled patient-level meta-analysis demonstrates that among STEMI patients undergoing primary PCI, EES as compared to 1st generation DES is associated with a significant reduction in ST and TVR at long-term follow-up.

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.

Prospective Identification of Stent Fracture by Enhanced Stent Visualization System During Percutaneous Coronary Intervention

BACKGROUND

No study has evaluated the clinical consequences of stent fracture (SF) detected during the index percutaneous coronary intervention (PCI). Thus, we sought to investigate the relationship between SF detected during PCI and clinical outcome.Methods and Results:We consecutively enrolled 832 patients with SF-predisposing factors undergoing 2nd-generation drug-eluting stent implantation and enhanced stent visualization (ESV) system evaluation to detect SF at index PCI. The primary endpoint was a 9-month device-oriented endpoint (DOCE, including cardiac death, target vessel myocardial infarction, and target lesion revascularization). We observed 136 SF in 115 patients (14% of study population). SF I-II was present in 78 patients (68% of patients with SF), and SF III-IV occurred in 37 patients (32%). DOCE at 9 months occurred in 135 patients (16% of the overall population). There was a significant difference in DOCE occurrence between the 3 groups (P=0.006 at log-rank), driven by the SF III-IV group (P=0.001 vs. no SF group, and P=0.01 vs. SF I-II group). In 23 cases of SF III-IV (62%) a further stent was implanted. DOCE occurrence was significantly higher in patients with "untreated" type III-IV SF as compared with the "treated" ones (9% vs. 79%, P<0.01).

CONCLUSIONS

The ESV system is helpful in detecting SF during the index PCI. Type III-IV SFs are associated with a higher incidence of DOCE.

Dynamic Respiratory Tortuosity of the Vertebral Artery Ostium

PURPOSE

To determine the prevalence of dynamic respiratory tortuosity (DRT) of the vertebral artery ostium (VAO) as well as to evaluate its correlation with in-stent restenosis (ISR) and stent fracture.

METHODS

From March 2012 to June 2015, 178 consecutive patients (mean age 65.2±5.8 years; 124 men) with symptoms of atherosclerotic vertebrobasilar ischemia underwent angiography prior to stent implantation in the vertebral, subclavian, and/or carotid arteries. In this cohort, 54 patients (mean age 67.3±5.3 years; 40 men) had VAO stent implantation. Angiography of the vertebral artery was recorded in 2 phases with breath-hold: deep inspiration (DIP) and deep expiration (DEP). Obvious VAO tortuosity was defined as any VAO angle ≤120° in DIP. Obvious VAO-DRT was defined as any VAO angle increasing ≥60° from DIP to DEP. Computed tomography angiography (CTA) or digital subtraction angiography was used in follow-up to detect ISR and stent fracture.

RESULTS

Of the 178 patients in this study, 21 (11.8%) had obvious VAO tortuosity and 8 (4.5%) had obvious VAO-DRT. Two of the 21 patients with obvious VAO tortuosity also had obvious VAO-DRT. Three of the 54 VAO stent patients had VAO-DRT. There were no correlations between VAO-DRT and age, sex, risk factors, body mass index, chronic obstructive pulmonary disease, asthma, or obvious VAO tortuosity (p>0.05). Over a mean follow-up of 28±10 months, there were 4 (7.4%) asymptomatic VAO ISR cases. Two (3.7%) were occlusions at 6 and 12 months, respectively; both were associated with stent fracture in patients with obvious VAO-DRT before stenting. Both stents fractured at the tortuous VAO region. VAO-DRT was correlated with stent fracture (Spearman ρ=0.81, p<0.01) and ISR (Spearman ρ=0.55, p<0.01).

CONCLUSION

VAO-DRT could be a risk factor for stent fracture and restenosis after VAO stent implantation. Angiography in both inspiration and expiration phases, especially the latter, should be considered before VAO stenting. Using a shorter stent to avoid crossing the tortuosity could reduce the occurrence of fracture.

Ten-year clinical outcomes after sirolimus-eluting stent implantation: Impact of an in-stent restenosis target lesion

Little is known about the long-term outcomes after first-generation sirolimus-eluting stent (SES) implantation. We aimed to investigate the clinical outcomes up to 10 years after SES implantation.

METHODS

The study population comprised 342 patients (504 lesions) who underwent SES implantation between January 2002 and December 2004. The median duration of follow-up was 3816 days (interquartile range [Q1-Q3], 3,705-3,883 days).

RESULTS

The cumulative event rate of definite stent thrombosis was 3.9%. The cumulative rate of target lesion revascularization (TLR) at 1, 5, and 10 years was 8.7%, 18.8%, and 31.1%, respectively, and the annual rate of TLR was 3.1%. Clinically driven TLR occurred at relatively constant rate during 10 years (2.0% per year). In a multivariate analysis, higher body mass index, hemodialysis, in-stent restenosis (ISR) target lesion, and total stent length >30 mm were independent risk factors of TLR within 5 years. An independent risk factor of TLR beyond 5 years was ISR target lesion.

CONCLUSIONS

Late TLR after SES implantation is a long-term hazard, lasting up to 10 years. The ISR target lesion is a risk factor of TLR during 10 years.

Incidence, predictive factors, and clinical impact of stent recoil in stent fracture lesion after drug-eluting stent implantation

BACKGROUND

Stent fracture (SF) after drug-eluting stent (DES) implantation was reported to be associated with target lesion revascularization (TLR). We have noted abnormal late acquired stent axial deformation in lesions after DES implantation, especially in SF lesions, and defined it as stent recoil (SR). We evaluated the incidence, predictive factors, and clinical impact of SR in SF lesions.

METHODS

Between 2003 and 2012, 5456 patients (11,712 lesions) underwent DES implantations and follow-up angiography within one year after the index procedure. SR was defined as an axial recoil deformation less than 80% of the stent diameter and SF was defined as the separation of stent segments or stent struts. SF and SR were confirmed by follow-up angiography. The primary endpoint was defined as clinically driven TLR.

RESULTS

SF was observed in 494 lesions (4.2%) and SR in 138 of SF lesions (27.9%). According to multinomial logistic regression analyses, severe calcification and ostial lesion in the right coronary artery were stronger predictive factors of SF with SR lesions. The cumulative incidences of any and clinically driven TLR at 5years were both significantly higher in the SF with SR group than in the SF without SR group (51.7% versus 35.0%, P<0.001; 22.2% versus 12.8%, P=0.019; respectively).

CONCLUSIONS

SR in SF lesions after DES implantation could be related to the lesion characteristics. SF with SR was highly associated with subsequent TLR compared with SF without SR.