Characteristics and Predictors of Drug-Eluting Stent Thrombosis - Results From the Multicenter Korea Stent Thrombosis (KoST)' Registry -

Factors associated with early, late, and very late stent thrombosis among patients with acute coronary syndrome undergoing coronary stent placement: analysis from the ATLAS ACS 2-TIMI 51 trial

Background

Stent thrombosis (ST) is an uncommon but serious complication of stent implantation. This study aimed to explore factors associated with early, late, and very late ST to help guide risk assessment and clinical decision-making on ST.

Methods

The analysis included patients who received stent placement for the index acute coronary syndrome (ACS). Cumulative incidence of ST was assessed at 30 days (early ST), 31-360 days (late ST), 361-720 days (very late ST), and up to 720 days. Cox proportional hazards models were used to assess associations between ST and various factors, including patient characteristics [i.e., age, sex, ACS presentation, history of hypertension, smoking, diabetes, prior myocardial infarction (MI), heart failure, prior ischemic stroke, and cancer], laboratory tests [i.e., positive cardiac biomarker, hemoglobin, platelet count, white blood cell (WBC) count], and treatment [i.e., drug-eluting stent (DES) vs. bare-metal stent (BMS) and anticoagulant with rivaroxaban vs. placebo].

Results

Among the 8,741 stented patients, 155 ST events (2.25%) occurred by Day 720. The cumulative incidences of early, late, and very late ST were 0.80%, 0.81%, and 0.77%, respectively. After multivariable adjustment, age ≥ 75 [hazard ratio (HR) = 2.13 (95% confidence interval, CI: 1.26-3.60)], a history of prior MI [HR = 1.81 (95% CI: 1.22-2.68)], low hemoglobin level [HR = 2.34 (95% CI: 1.59-3.44)], and high WBC count [HR = 1.58 (95% CI: 1.02-2.46)] were associated with a greater risk of overall ST, whereas DES [HR = 0.56 (95% CI: 0.38-0.83)] and rivaroxaban therapy [HR = 0.63 (95% CI: 0.44-0.88)] were associated with a lower risk of overall ST up to 720 days. Low hemoglobin level and high WBC count were associated with early ST (low hemoglobin: HR = 2.35 [95% CI: 1.34-4.12]; high WBC count: HR = 2.11 [95% CI: 1.17-3.81]). Low hemoglobin level and prior MI were associated with a greater risk of late ST (low hemoglobin: HR = 2.32 [95% CI: 1.26-4.27]; prior MI: HR = 2.98 [95% CI: 1.67-5.31]), whereas DES was associated with a lower risk of late ST [HR = 0.33 (95% CI: 0.16-0.67)]. Age ≥75 years was associated with very late ST.

Conclusion

The study identified positive and negative associations with early, late, and very late ST. These variables may be useful in constructing risk assessment models for ST.

Clinical Trial Registration

http://www.clinicaltrials.gov, identifier NCT00809965.

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.

Comparisons of Drug-Eluting Balloon versus Drug-Eluting Stent in the Treatment of Young Patients with Acute Myocardial Infarction

BACKGROUND

The incidence of acute myocardial infarction (AMI) in the younger population has been increasing gradually in recent years. The objective of the present study is to investigate the safety and effectiveness of drug-eluting balloons (DEBs) in young patients with AMI.

METHODS

All consecutive patients with AMI aged ≤ 45 years were retrospectively enrolled. The primary endpoint was a device-oriented composite endpoint (DOCE) of cardiac death, target vessel myocardial infarction (MI), or target lesion revascularization (TLR). The secondary study endpoints included heart failure and major bleeding events.

RESULTS

A total of 276 young patients presenting with AMI were finally included. The median follow-up period was 1155 days. Patients treated with DEBs had a trend toward a lower incidence of DOCEs (3.0% vs. 11.0%, p = 0.12) mainly driven by the need for TLR (3.0% vs. 9.1%, p = 0.19) than those treated with DESs. No significant differences between the two groups were detected in the occurrence of cardiac death (0.0% vs. 0.5%, p = 0.69), MI (0.0% vs. 1.4%, p = 0.40), heart failure (0.0% vs. 1.9%, p = 0.39), or major bleeding events (1.5% vs 4.8%, p = 0.30). Multivariate regression analysis showed that DEBs were associated with a trend toward a lower risk of DOCEs (HR 0.13, 95% CI [0.02, 1.05], p = 0.06).

CONCLUSIONS

The findings of the present study suggested that DEBs might be a potential treatment option in young patients with AMI. A larger scale, randomized, multicenter study is required to investigate the safety and effectiveness of DEBs in this setting.

Acute Intraprocedural Thrombosis After Flow Diverter Stent Implantation: Risk Factors and Relevance of Standard Observation Time for Early Detection and Management

PURPOSE

Acute intraprocedural thrombosis (AIT) is a severe complication of flow diverter stent (FDS) implantation for the treatment of intracranial aneurysms. Even though device-related thromboembolic complications are well known, there are no acknowledged risk factors nor defined surveillance protocols for their early detection. This study aimed to demonstrate that an angiographic active surveillance is effective to detect and treat AIT. Furthermore, we investigated risk factors for the occurrence of AIT.

METHODS

A prospective institutional protocol consisting of a defined observation period of 30 min following FDS deployment was established to detect AIT. Overall incidence, as well as the efficacy and safety of AIT treatment were assessed. Moreover, radiological and clinical outcomes of patients with AIT were analyzed. The influence of various patient- and procedure-related factors on the occurrence of AIT was investigated using multivariable forward logistic regression.

RESULTS

During active surveillance twelve cases of AIT were observed among a total of 161 procedures (incidence: 7.5%). The median time of first observation was 15.5 min (IQR 9.5) after FDS implantation. The early recognition of AIT ensured a prompt treatment with intravenous application of a glycoprotein IIb/IIIa inhibitor, which led to complete thrombus resolution in all cases without hemorrhagic complications. Patients with pre-existing arterial hypertension and side branches originating from the aneurysmal sac had a higher risk of AIT (respectively OR, 9.844; OR, 3.553). There were two cases of re-thrombosis in the short-term postoperative period, of whom one died. The remaining patients with AIT had a good clinical outcome.

CONCLUSION

Active surveillance for 30 min after FDS implantation is an effective strategy for early detection and ensuing treatment of AIT and can thus prevent secondary sequalae. Hypertension and side branches originating from the aneurysmal sac may increase the risk of AIT.

Evolution of drug-eluting coronary stents: a back-and-forth journey from the bench-to-bedside

Coronary stents have revolutionized the treatment of coronary artery disease. Compared with balloon angioplasty, bare-metal stents effectively prevented abrupt vessel closure but were limited by in-stent restenosis due to smooth muscle cell proliferation and neointimal hyperplasia. The first-generation drug-eluting stent (DES), with its antiproliferative drug coating, offered substantial advantages over bare-metal stents as it mitigated the risk of in-stent restenosis. Nonetheless, they had several design limitations that increased the risk of late stent thrombosis. Significant advances in stent design, including thinner struts, enhanced polymers' formulation, and more potent antiproliferative agents, have led to the introduction of new-generation DES with a superior safety profile. Cardiologists have over 20 different DES types to choose from, each with its unique features and characteristics. This review highlights the evolution of stent design and summarizes the clinical data on the different stent types. We conclude by discussing the clinical implications of stent design in high-risk subsets of patients.

Incidence, Predictors, and Outcomes of Acute and Sub-acute Stent Thrombosis after Emergency Percutaneous Coronary Revascularization with Drug-Eluting Stents: A Prospective Observational Study

Background:

Stent thrombosis (ST) remains the most feared complication of percutaneous coronary intervention (PCI). Therefore, this study aimed to determine acute and sub-acute ST incidence, predictors, and outcomes after primary PCI.

Methods:

This prospective observational study included patients who had undergone primary PCI at a tertiary care cardiac center. All the patients were followed at 30-days of index hospitalization for the incidence of acute or sub-acute ST. ST was further categorized as definite, probable, or possible per the Academic Research Consortium definition. All the survivors of ST were followed after 6-months for the incidence of major adverse cardiovascular events.

Results:

An aggregate of 1756 patients were included with 79% (1388) male patients and mean age was 55.59 ± 11.23 years. The incidence of ST was 4.9% (86) with 1.3% (22) acute and 3.6% (64) sub-acute. ST was categorized as definite in 3.3% (58) and probable in 1.6% (28). Independent predictor of ST were observed to be male gender (odds ratio (OR); 2.51 [1.21–5.2]), left ventricular end-diastolic pressure ≥20 mmHg (OR; 2.55 [1.31–4.98]), and pre-procedure thrombolysis in myocardial infarction (TIMI) flow 0 (OR; 3.27 [1.61–6.65]). Cumulative all-cause mortality among patients with ST after 164.1 ± 76.2 days was 46.5% (40/86).

Conclusion:

We observed a substantial number of patients vulnerable to the acute or sub-acute ST after primary PCI. Male gender, LVEDP, pre-procedure TIMI flow grade can be used to identify and efficiently manage highly vulnerable patients.

Gender-Associated Outcomes Following Percutaneous Coronary Intervention With a Third-Generation, Ultrathin-Strut Drug-Eluting Stent: A Real-World, Single-Center Experience

Introduction

In recent years, the new third-generation ultrathin bioresorbable-polymer sirolimus-eluting stent (BP-SES), characterized by some of the thinnest struts among commercially available devices (60–80 μm) and an amorphous silicon carbide coating, has been introduced for the treatment of coronary artery disease (CAD). The present study aimed to assess different clinical outcomes and safety of this drug-eluting stent in male and female patients in a real-world setting.

Methods

The present study is a retrospective analysis including all patients treated with BP-SES between January 2017 and December 2019 at a single high-volume center. Follow-up data, including stress test results and clinical setting, were collected during outpatient visits or by telephone contact. Patients symptomatic for angina or with a positive stress test were addressed to CT scan/coronary angiogram. The main study outcome was target lesion failure (TLF), defined as a composite of cardiovascular death, target vessel myocardial infarction, or target lesion revascularization.

Results

Overall, 66 (15.9%) female and 349 (84.1%) male patients were included; women were older (median age 70 vs. 66, P = 0.003) and with a lower body mass index (BMI) (25.0 vs. 26.1, P = 0.010) compared to men, with no other relevant differences in baseline characteristics. Indication for percutaneous coronary intervention (PCI) was acute coronary syndrome in 86 (20.7%) of the cases, with no significant differences between male and female patients. A total of 558 lesions were treated with BP-SES stents, 90 in women and 468 in men (1.36 vs. 1.34 lesions per patient, P = 0.83); cumulative stent length (33.6 vs. 38.4 mm, P = 0.078), and mean stent diameter (2.92 vs. 3.0 mm, P = 0.39) did not differ in women compared to men. Technical and clinical successes were achieved in all patients. Stent thrombosis (ST) occurred in 2 (0.5%) patients, both men. TLF occurred in 10 (2.9%) men and 2 (3.0%) women after a median follow-up of 402 days, without significant differences at log-rank analysis (2.34 events per 100 patient-years in men, 2.53 in women; P = 0.80).

Conclusion

Ultrathin struts BP-SES showed to be a safe and effective option for the treatment of CAD in both women and men, with a very low ST rate and favorable long-term outcomes.

Relationship between atherogenic index of plasma and stent thrombosis in patients with acute coronary syndrome

OBJECTIVE

Stent thrombosis (ST) is an uncommon but serious complication in patients undergoing percutaneous coronary intervention (PCI). This study aimed to investigate the effect of atherogenic index of plasma (AIP) on ST.

METHODS

Among the 10,258 patients who underwent coronary angiography between January 2018 and December 2020, 239 patients who underwent PCI with the diagnosis of acute coronary syndrome (ACS) due to ST were included as the study group (ST group) and 459 patients who underwent percutaneous intervention for ACS and did not have any in-stent lesion as the control group (non-ST group). ST classification was done according to the Academic Research Consortium definition.

RESULTS

The mean age of the patients was 63.3±10.6 years (483 male, 69.2%). The groups were similar in terms of characteristic properties, comorbidities, and the drugs being used (p>0.05 for all). Drug eluting stents were used in 86.5% of the patients. In the ST group, the median time from stent implantation to thrombosis was 285 days. Mean AIP and the ratio of triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) were statistically significantly higher in the ST group than in the controls (p<0.001 and p=0.018, respectively), and a positive correlation was observed between time from stent implantation to thrombosis and AIP and TG/HDL-C (rS=0.229, p=0.010 and rS=0.222, p=0.010, respectively). Multivariate logistic regression analysis revealed that stent length, prior ST elevation myocardial infarction, TG/HDL-C, and AIP were independent predictors of ST.

CONCLUSION

AIP is an easy calculable biomarker, and the performance of AIP to predict ST is better than TG/HDL-C.

A Case of Percutaneous Thrombectomy for Internal Carotid Artery Occlusion due to In-Stent Thrombosis Following Stent-Assisted Intra-Aneurysmal Embolization

Objective

In-stent thrombosis (IST) is a known complication after stent-assisted coil (SAC) embolization. We report a case of mechanical thrombectomy using a stent retriever (SR) for IST and share our experience with this treatment to prevent a poor outcome in future cases.

Case Presentation

The patient was a 62-year-old man. SAC embolization for an unruptured left internal carotid artery (ICA) aneurysm was performed. Three weeks after discharge, right hemiparesis and aphasia developed. Magnetic resonance imaging (MRI) demonstrated cerebral infarction in the left middle cerebral artery (MCA) territory and the left ICA was occluded. His relatives told us that the patient discontinued taking antiplatelet drugs. IST was diagnosed and emergency thrombectomy was performed. First, we tried to introduce an aspiration catheter or balloon catheter into the occluded lesion, but they were unable to be sufficiently inserted to the distal site. Therefore, we used a SR even though it carried a risk of friction on the deployed stent. The occluded artery was finally recanalized using the SR, but the stent became shortened. For the treatment strategy, sufficient medication (antithrombogenic agents and edaravone) should be administered first, followed by mechanical treatment. In mechanical treatment, thrombus fragmentation with a guidewire or balloon and aspiration should be attempted first. New aspiration catheters to carry the devices to the far distal site easily are now available.

Conclusion

SRs cannot be utilized for thrombectomy with a stent. In emergency situations, careful consideration during troubleshooting rather than using a SR is needed.

Bioresorbable Scaffolds: Contemporary Status and Future Directions

Percutaneous coronary intervention, which is safe, effective, and timely, has become an important treatment for coronary artery diseases and has been widely used in clinical practice. However, there are still some problems that urgently need to be solved. Permanent vessel caging through metallic implants not only prevents the process of positive vessel remodeling and the restoration of vascular physiology but also makes the future revascularization of target vessels more difficult. Bioresorbable scaffolds (BRSs) have been developed as a potential solution to avoid the above adverse reactions caused by permanent metallic devices. BRSs provide temporary support to the vessel wall in the short term and then gradually degrade over time to restore the natural state of coronary arteries. Nonetheless, long-term follow-up of large-scale trials has drawn considerable attention to the safety of BRSs, and the significantly increased risk of late scaffold thrombosis (ScT) limits its clinical application. In this review, we summarize the current status and clinical experiences of BRSs to understand the application prospects and limitations of these devices. In addition, we focus on ScT after implantation, as it is currently the primary drawback of BRS. We also analyze the causes of ScT and discuss improvements required to overcome this serious drawback and to move the field forward.

Evaluation of Acute In-stent Thrombosis during Stent-assisted Coil Embolization of Unruptured Intracranial Aneurysms

Stent-assisted coil embolization (SACE) is used to address wide-necked or complex aneurysms. However, periprocedural and/or late in-stent thrombosis (IST) elicit neurological events. We investigated the incidence and timed the development of acute IST during SACE with braided- or laser-cut stents in a retrospective study. Between May 2013 and April 2018, we evaluated 11 ISTs that occurred in the course of 185 SACE procedures (self-expandable laser-cut stent, n = 128; braided stent, n = 57). The onset of IST was measured from the time of stent placement. All 11 patients with IST were treated with anticoagulants and underwent hypertension induction. Post-procedural neurological events due to IST were also recorded. The implantation of a laser-cut stent elicited IST in 5 of 128 patients (3.9%); braided stent placements resulted in IST in 6 of 57 patients (10.5%) (P = 0.1). The mean stent diameter was significantly smaller in patients with-IST than without IST (3.0 ± 0.9 mm vs. 4.5 ± 0.7 mm, P = 0.007). The mean interval between stent placement and IST onset was 19 ± 7.7 min; it was significantly earlier for braided- than laser-cut stents (17.5 ± 4.1 min vs. 29.0 ± 4.8 min, P = 0.006). All ISTs were resolved during the procedure. Three patients experienced postoperative neurologic events. We recommend the meticulous and prolonged monitoring of images after stent placement because delayed intraoperative IST can occur especially when laser-cut stents are used.

A risk scoring system to predict coronary stent thrombosis

OBJECTIVE

Stent thrombosis (ST) is a potentially life-threatening complication of percutaneous coronary intervention (PCI). We aimed to develop a scoring system to predict the risk of ST following PCI.

RESEARCH DESIGN AND METHODS

Odds ratios (ORs) for risk factors associated with ST were identified from a meta-analysis based on a systematic literature review, and through consensus expert opinion (Delphi-RAND method). The combined ORs were used to calculate risk scores for acute (within 24 hours), early (within 30 days) and late (31 days to 1 year) ST. Risk scores were validated against patient-level data from the TRITON-TIMI 38 study. Twenty risk factors were identified.

RESULTS

The most highly predictive factor for early and late ST was "incomplete duration of dual antiplatelet therapy". Derived total risk scores ranged from 0 to 22 for acute and early ST, and from 0 to 20 for late ST. Increasing scores were associated with an increasing risk of ST when applied to trial data. Model discrimination was 0.60 (p = .0028), 0.67 (p < .0001) and 0.66 (p < .0001) for acute, early and late ST respectively, indicating good discriminatory power for predicting ST. Key limitations included a lack of published data on acute ST, resulting in a risk score for this time point being based predominantly on expert opinion, and that it was not possible to map all risk factors to variables collected in the TRITON-TIMI 38 study.

CONCLUSION

Our weighted scoring system may help to stratify ST risk and individualize antiplatelet therapy in patients undergoing PCI.

Incidence, Implications, and Predictors of Stent Thrombosis in Acute Myocardial Infarction

Stent thrombosis (ST) remains a catastrophic problem in patients undergoing percutaneous coronary intervention (PCI). However, a paucity of data exist regarding the incidence, implications, and predictors of ST in patients with acute myocardial infarction (AMI). We consecutively enrolled patients with AMI in the CardiOvascular Risk and idEntificAtion of potential high-risk population in AMI registry who underwent PCI from January 2004 to December 2009 and analyzed definite or probable ST according to Academic Research Consortium definitions. The median follow-up duration was 41.9 months. Definite or probable ST occurred in 136 patients (3.7%), including 44 with early ST (1.0%), 38 with late ST (0.9%), and 54 with very late ST (2.0%). The annual incidence of very late ST ranged from 0.5% to 0.6%. The all-cause mortality rate after ST was 29%, which was higher than that for patients without ST (17%; p <0.001). The independent predictors of ST were no-reflow phenomenon (hazard ratio [HR] 1.96, 95% confidence interval [CI] 1.28 to 3.03), decreased left ventricular ejection fraction (HR 1.70, 95% CI 1.21 to 2.40), anemia (HR 1.54, 95% CI 1.09 to 2.18), and a mean stent diameter <3.0 mm (HR 1.53, 95% CI 1.04 to 2.27). ST is not uncommon in patients with AMI and continues to occur beyond 1 year after PCI, irrespective of the stent type or clinical presentation. Patients with ST are associated with higher mortality than patients without ST. No reflow, decreased left ventricular ejection fraction, anemia, and a mean stent diameter <3.0 mm are independent predictors of ST.

Evaluation of the incremental prognostic value of the combination of CYP2C19 poor metabolizer status and ABCB1 3435 TT polymorphism over conventional risk factors for cardiovascular events after drug-eluting stent implantation in East Asians

PURPOSE

We evaluated the incremental prognostic value of combining the CYP2C19 poor metabolizer (PM) and ABCB1 3435 TT for adverse clinical outcomes over conventional risk factors in a percutaneous coronary intervention (PCI) cohort.

METHODS

We enrolled 2,188 patients. The primary end point was a composite of death from any cause, nonfatal myocardial infarction (MI), and stroke during 1-year follow-up. The population was stratified into the following four groups: CYP2C19 EM/IM+ABCB1 3435 CC/CT, CYP2C19 EM/IM+ABCB1 3435 TT, CYP2C19 PM+ABCB1 3435 CC/CT, and CYP2C19 PM+ABCB1 3435 TT.

RESULTS

A total of 87 (3.97%) primary end-point events occurred (64 deaths, 8 non-fatal MIs and 15 strokes). Multivariate Cox analysis indicated that CYP2C19 PM+ABCB1 3435 TT status was a significant predictor of the primary end point (hazard ratio = 4.51, 95% confidence interval (CI) = 1.92-10.58). However, addition of combined genetic status to the clinical risk model did not improve the model discrimination (C-statistic = 0.786 (95% CI = 0.734-0.837) to 0.785 (95% CI = 0.733-0.838)) or risk reclassification (categorical net reclassification improvement (0.040, P = 0.32), integrated discrimination improvement (0.021, P = 0.026)).

CONCLUSIONS

In a real-world East Asian PCI population taking clopidogrel, although the concurrent presence of CYP2C19 PM and ABCB1 TT is a strong independent predictor of adverse outcomes, the combined status of two at-risk variants does not have an incremental prognostic value beyond that of the conventional clinical risk factors.Genet Med 18 8, 833-841.

Usefulness of the Left Anterior Descending Coronary Artery Wrapping Around the Left Ventricular Apex to Predict Adverse Clinical Outcomes in Patients With Anterior Wall ST-Segment Elevation Myocardial Infarction (from the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction Trial)

The association between anatomic features of the left anterior descending artery (LAD) and outcomes in patients with anterior ST-segment elevation myocardial infarction (STEMI) has not been fully investigated. We sought to clarify the impact of an LAD coronary artery wrapping around the left ventricular (LV) apex on clinical outcomes in patients with anterior STEMI. Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction enrolled patients with STEMI presenting <12 hours after symptom onset who underwent primary percutaneous coronary intervention. Patients with a culprit lesion in the LAD were categorized as (1) LAD wrapping around the LV apex (wrap-around LAD, n = 871) versus (2) LAD not wrapping around the LV apex (non-wrap-around LAD, n = 224). Killip class ≥II, dysrhythmia, and LV mural thrombi were more frequently observed in the wrap-around LAD group; LV ejection fraction was worse in the wrap-around LAD group (54.5% vs 58.7%, p = 0.006). At 3 years of follow-up, major adverse cardiac events (death, stroke, or stent thrombosis, 12.7% vs 5.4%, p = 0.002), death (6.6% vs 3.2%, p = 0.052), stroke (1.9% vs 0.5%, p = 0.12), stent thrombosis (5.6% vs 2.3%, p = 0.047), and severe heart failure (4.5% vs 1.4%, p = 0.03) were more common in patients with a wrap-around LAD versus those with a non-wrap-around LAD. Multivariate analysis indicated that a wrap-around LAD independently and significantly predicted major adverse cardiac events (hazard ratio 2.18, p = 0.02) and severe heart failure (odds ratio 3.31, p = 0.049) in patients with an anterior STEMI. In conclusion, a wrap-around LAD predicted adverse clinical outcomes at 3 years in patients with anterior STEMI who underwent primary percutaneous coronary intervention.

Mechanism of edge restenosis after drug-eluting stent implantation. Angulation at the edge and mechanical properties of the stent

BACKGROUND

Edge restenosis is not an unusual finding after implantation of drug-eluting stents (DES). We hypothesized that mechanical stress imposed on the stent edge would cause vessel wall injury and inflammation, which may consequently lead to edge restenosis.

METHODS AND RESULTS

In total, 1,496 patients were implanted with a sirolimus-eluting stent (SES), paclitaxel-eluting stent (PES) or zotarolimus-eluting stent (ZES) in Seoul National University Hospital between 2007 and 2009. Binary restenosis occurred in 161 lesions in 119 patients. We retrospectively compared the 3 DES with regard to the percentage of edge stent restenosis among all cases of restenosis. We also evaluated the maximal, minimal, and Δ (maximal angle-minimal angle) angles. The percentage of edge restenosis was higher for SES than for ZES (37.5% vs. 16.7%, P=0.017). Maximal angle at the proximal edge was 64.82°±33.46° for 26 stents with proximal edge restenosis compared with 31.84°±31.51° for 89 stents without proximal edge restenosis (P=0.001). The Δ angle was also significantly different between the 2 groups (14.81°±15.98° vs. 7.60°±8.86°, P=0.035). Similar findings were observed for distal edge restenosis. Both the maximal angle (39.09°±21.04° vs. 22.71°±22.83°, P=0.010) and Δ angle (20.23°±15.39° vs. 9.18°±9.66°, P=0.016) at the distal edge were significantly different between the 2 groups.

CONCLUSIONS

Physical stress determined by angulation at the stent edge segment and biomechanical properties of the DES can be considered as one of the plausible mechanisms for edge stent restenosis.

Long-term efficacy of sirolimus-eluting stent for small vessel disease--subanalysis of Cypher Stent Japan Post-Marketing Surveillance Registry

BACKGROUND

Percutaneous coronary intervention for lesions with small vessel diameter may have high event rates. Although drug-eluting stents reduce the risk of restenosis, the long-term efficacy of drug-eluting stent implantation in small vessels is unclear.

METHODS AND RESULTS

We reviewed the data of Cypher Stent Japan Post-Marketing Surveillance Registry including 2356 lesions of 1959 patients, and retrospectively investigated the angiographic outcomes at 8 months, and the clinical outcomes at 1800 days after sirolimus-eluting stent (SES) implantation in vessels with diameter less than 2.5mm (small vessel group) compared to that with diameter of 2.5mm or more (non-small vessel group). The rate of major adverse cardiac events (MACE) at 1800 days was slightly higher in the small vessel group than in the non-small vessel group, but not statistically significant (24.4% vs 21.0%, p=0.086). The rate of target lesion revascularization was higher in the small vessel group than in the non-small vessel group (10.2% vs 6.4%, p=0.004). The rate of stent thrombosis was almost the same in the two groups. Multivariate Cox hazard model analysis revealed that a vessel diameter less than 2.5mm was not an independent risk factor for MACE.

CONCLUSION

SES implantation for vessels with diameter less than 2.5mm is safe and provides good long-term outcomes.

Sirolimus-Versus Zotarolimus-Eluting Stents in Acute Coronary Syndromes With C Type Left Anterior Descending Artery Lesions: A Three-Year Clinical Follow-Up

Background

Drug-eluting stents have improved the efficacy of percutaneous coronary intervention and made it the preferred therapy in the treatment of ischemic heart diseases including acute coronary syndromes. The objective of the study was to compare the clinical efficacy and safety of sirolimus-eluting stent with that of zotarolimus-eluting stent following percutaneous coronary intervention for acute coronary syndrome patients with C-type left anterior descending stenosis.

Methods

A total of 154 acute coronary syndrome patients with C-type lesions in the left anterior descending artery, requiring a stent > 28 mm in length, were randomized into two groups to receive either sirolimus- (n = 74) or zotarolimus-eluting stent (n = 80). The follow-up period after stent implantation was approximately 36 months. The primary endpoint was a major cardiac event (a composite of cardiac death, myocardial infarction, or ischemia-related target vessel revascularization), and the secondary endpoint included these individual end points plus stent thrombosis.

Results

After 3 years follow-up, the rate of the primary end point (major cardiac event: cardiac death, myocardial infarction, ischemia-related target vessel revascularization) was 16% in the sirolimus group (n = 12) versus 11.2% in the zotarolimus group (n = 9) (P = 0.2). Although there were four cases of stent thrombosis with sirolimus-eluting stent and one with zotarolimus-eluting stent (4.0% sirolimus vs. 1.25% zotarolimus; P = 0.2), neither non-Q myocardial infarction (4.0%sirolimus vs. 1.25% zotarolimus; P = 0.2) nor stent thrombosis, differed significantly.

Conclusions

Although zotarolimus-eluting stent implantation showed more favorable results with respect to stent thrombosis and major adverse cardiac event rates compared to sirolimus-eluting stent implantation, statistically, both stent groups have nearly similar clinical safety and efficacy in the treatment of acute coronary syndromes with C-type lesions in the left anterior descending artery disease.

Intravascular ultrasound and histopathological observations in a patient with very late sirolimus-eluting stent thrombosis

This case report describes an autopsy case of very late stent thrombosis, which was associated with intravascular ultrasound findings of late-acquired stent malapposition with thrombotic materials and marked positive vascular remodeling at the site of the sirolimus-eluting stent implantation. Histopathological examination showed both destructive and proliferative reactions had occurred in the same stented coronary arterial wall 44 months after sirolimus-eluting stent implantation. Long-lasting severe local inflammation beyond healing reaction, causing vessel enlargement, may be related to very late stent thrombosis.

Rodriguez A, Bramucci E, Moreno R, Piva T, Sheiban I, Pasquetto G, Prati F, Nazzaro MS, Ferrari R, Valgimigli M. Sex-specific benefits of sirolimus-eluting stent on long-term outcomes in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention: insights from the Multicenter Evaluation of Single High-Dose Bolus Tirofiban Versus Abciximab With Sirolimus-Eluting Stent or Bare-Metal Stent in Acute Myocardial Infarction Study trial

OBJECTIVES

We assessed the relation between female sex and sirolimus-eluting stent (SES) use on long-term outcomes in acute myocardial infarction.

BACKGROUND

There are no data on sex-specific differences in long-term benefit of SES use compared with bare-metal stent (BMS) use among patients undergoing primary percutaneous coronary interventions.

METHODS

We performed a post hoc analysis of the MULTISTRATEGY trial. Hazard ratios (HRs) of events with 95% CI for sex and stent type were computed using Cox proportional regression with adjustment for confounders.

RESULTS

A total of 744 patients, 64 years old (55-73 years old), 179 (24.1%) women, were enrolled. After a follow-up of 1,080 days, SES use was associated with a significant reduction of major adverse cardiovascular events, that is, the composite of all-cause death, reinfarction, or clinically driven target vessel revascularization (TVR) (13.9% vs 23.6%, adjusted HR 0.62, 95% CI 0.41-0.94, P = .026) and of TVR (6.1% vs 15.1%, adjusted HR 0.35, 95% CI 0.19-0.63, P < .001) in men. Conversely, SES use was not associated to a better outcome among women (major adverse cardiovascular events 21.9% in SES vs 18.2% in the BMS group, adjusted HR 1.27, 95% CI 0.53-3.02, P = .59; TVR 6.6% vs 9.1%, adjusted HR 0.62, 95% CI 0.17-2.21, P = .46).

CONCLUSIONS

In this analysis, the clinical benefit of SES use, over BMS, at 3-year follow-up was restricted to men and was not observed among women.