Subacute in-stent thrombosis after carotid artery stenting in a patient with gene polymorphisms associated with aspirin and clopidogrel resistance: a case report.

BACKGROUND: Carotid artery stenting (CAS) is a key treatment option for moderate to severe carotid artery stenosis. Carotid stent thrombosis (CST), a rare complication of CAS, has gained significant attention because of its catastrophic nature. More evidences are needed to guide the diagnosis and treatment of CST. CASE PRESENTATION: This study reports a rare case of sub-acute CST following CAS in a 50-year-old male patient who had experienced repeated cerebrovascular events on the premise of taking antiplatelet drugs. He also suffered an occlusion of the left middle cerebral artery (MCA) in the M2 segment, likely caused by an embolus detached from the stent thrombus. The cause of CST in this patient was presumed to be dual antiplatelet resistance (AR), as indicated by genetic testing. After treated with guide catheter-directed thrombolysis, thrombus aspiration, and a second round of thrombolysis, his in-stent thrombus was basically cleared. His M2 occlusion was resolved by mechanical thrombectomy using the Solitaire FR/Stent with Intermediate Catheter Assisting technique. The patient recovered well after replacement of antiplatelet drugs, and no new thromboembolic event occurred during the 13-month follow-up period. CONCLUSIONS: The occurrence rate of AR-related CST may be underestimated as the cause of majority CST cases remains unclear. Implementation of genetic test for aspirin and clopidogrel resistance may be helpful to find the possible cause of CST and to avoid future repeated cerebrovascular events by replacement of antiplatelet drugs.

ICARUS score for predicting peri-procedural bleeding in patients undergoing percutaneous coronary intervention with cangrelor.

BACKGROUND: Tools for precise prediction of bleeding risk in patients undergoing percutaneous coronary intervention (PCI) with cangrelor are lacking. METHODS: Consecutive patients undergoing PCI and treated with cangrelor in 7 centers were retrospectively enrolled. The primary endpoint was Bleeding Academic Research Consortium (BARC) BARC 2, 3, or 5 bleeding 48 h after PCI. Predictors of BARC 2-5 bleeding were identified in a derivation cohort and combined into a numerical risk score. Discrimination and calibration were assessed in the derivation and validation cohorts. A threshold to define high bleeding risk (HBR) was identified and its diagnostic accuracy was compared with that of currently recommended bleeding risk scores. RESULTS: 1071 patients undergoing PCI with cangrelor were included. Fifty-four patients (5 %) experienced a BARC 2-5 bleeding, of whom 24 (44 %) from the access site. Age ≥ 75 years (odds ratio [OR] 2.58, 95 % confidence interval [CI] 1.21-5.48, p = 0.01), acute coronary syndrome at presentation (OR 8.14, 95 % CI 2.28-52, p = 0.01), and femoral access (OR 6.21, 95 % CI 2.71-14, p < 0.001) independently predicted BARC 2-5 bleeding at 48 h after PCI. The three items were combined to form a new risk score, the ICARUS score, showing good discrimination in both the derivation (area under the curve [AUC] 0.78) and internal validation (AUC 0.77) cohorts, and excellent calibration. An ICARUS score > 9 points accurately identified patients at HBR, showing better discrimination than other risk scores. CONCLUSIONS: A risk score based on age, clinical presentation and access site, predicts the risk of periprocedural bleeding in patients receiving cangrelor (ClinicalTrials.gov ID: NCT05505591).

[Research progress in coatings with active compounds and extracts of traditional Chinese medicines for coronary intervention devices].

In recent years, the incidence and mortality rates of cardiovascular diseases in China have kept rising, with no significant reduction in disease burden observed. Percutaneous coronary intervention(PCI) is an effective approach for treating coronary artery disease. Drug-eluting stents and drug-coated balloons are currently the most common PCI devices used in clinical practice. However, challenges with restenosis and late-stage thrombotic events persist. Inhibiting the proliferation of vascular smooth muscle cells while enhancing endothelial cell activity is crucial for reducing restenosis and preventing thrombosis, and it remains a challenge in research. The active compounds and extracts of traditional Chinese medicine(TCM), particularly the combinations of active compounds in coatings, possess multi-target potential and serve as a supplement to coatings prepared from synthetic compounds. This review elucidates the application of TCM active compounds(such as arsenic trioxide, paclitaxel, hirudin, tetramethylpyrazine, emodin, oxymatrine, and curcumin), combinations of TCM active compounds(paclitaxel/hirudin, geniposide/baicalin), and TCM extracts(such as Curcumae Rhizoma extract and Tripterygium hypoglaucum extract) in the coatings for PCI devices in recent years. Furthermore, this review expounds the current challenges and future prospects in this field, giving insights into the innovation of PCI devices.

Identification of endothelial protein C receptor as a novel druggable agonistic target for reendothelialization promotion and thrombosis prevention of eluting stent.

The commercially available drug-eluting stent with limus (rapamycin, everolimus, etc.) or paclitaxel inhibits smooth muscle cell (SMC), reducing the in-stent restenosis, whereas damages endothelial cell (EC) and delays stent reendothelialization, increasing the risk of stent thrombosis (ST) and sudden cardiac death. Here we present a new strategy for promoting stent reendothelialization and preventing ST by exploring the application of precise molecular targets with EC specificity. Proteomics was used to investigate the molecular mechanism of EC injury caused by rapamycin. Endothelial protein C receptor (EPCR) was screened out as a crucial EC-specific effector. Limus and paclitaxel repressed the EPCR expression, while overexpression of EPCR protected EC from coating (eluting) drug-induced injury. Furthermore, the ligand activated protein C (APC), polypeptide TR47, and compound parmodulin 2, which activated the target EPCR, promoted EC functions and inhibited platelet or neutrophil adhesion, and enhanced rapamycin stent reendothelialization in the simulated stent environment and in vitro. In vivo, the APC/rapamycin-coating promoted reendothelialization rapidly and prevented ST more effectively than rapamycin-coating alone, in both traditional metal stents and biodegradable stents. Additionally, overexpression or activation of the target EPCR did not affect the cellular behavior of SMC or the inhibitory effect of rapamycin on SMC. In conclusion, EPCR is a promising therapeutical agonistic target for pro-reendothelialization and anti-thrombosis of eluting stent. Activation of EPCR protects against coating drugs-induced EC injury, inflammatory cell, or platelet adhesion onto the stent. The novel application formula for APC/rapamycin-combined eluting promotes stent reendothelialization and prevents ST.

Clinical Impact of Intracoronary Imaging in the Management of Stent Thrombosis.

Objectives: Use of intracoronary imaging (ICI) in cases of stent thrombosis (ST) is recommended and tailored treatment appears reasonable. Nevertheless, data supporting such a strategy are lacking. The aim of this study was to evaluate the clinical impact of ICI in the management of ST. Methods: The unadjusted study population was consecutive patients with definite ST presenting in a single tertiary cardiac centre and undergoing percutaneous coronary intervention (PCI). The presumed major mechanism of ST was assigned according to the real-time ICI interpretation by the PCI operator. Propensity score matching was performed with regard to ICI use to form the adjusted population and Kaplan-Meier analysis was applied to compare survival free of cardiac death (CD) or target lesion revascularization (TLR). Results: The unadjusted population included 130 ST patients, with the majority presenting with ST-elevation myocardial infarction (STEMI) (88%) and very late ST (86%). ICI was performed in 45 patients, of whom optical coherence tomography (OCT) was performed in 30 cases. When the individual ST mechanisms were viewed as groups, there was an interaction observed between type of treatment (stent vs. non-stent) and ST mechanism, with non-stent treatment being more prevalent in cases of underexpansion, malapposition, in-stent restenosis and mechanism uncertainty. After application of matching, two groups of 30 patients were formed. ICI-guided management resulted in better survival free of CD-TLR at 2 years (93% vs. 73%, p = 0.037). Conclusions: Intracoronary imaging guidance during PCI for ST had a direct impact on management (stent vs. non-stent) and resulted in a lower event rate at mid-term follow-up when propensity matched analysis was applied.

Influence of stent strut and its associated injury on thrombus formation: A dissipative particle dynamics study.

Vascular stent intervention is a pivotal treatment for coronary atherosclerosis, though in-stent thrombosis remains a significant postoperative complication with an unclear underlying mechanism. This study utilized dissipated particle dynamics analysis to investigate the impact of stent and its injury on platelet behavior. The findings suggest that thrombus formation upstream of the stent is mainly initiated by upstream arterial injury, which leads to increased platelet accumulation and activation in that area. While thrombosis downstream of the stent is more directly influenced by the stent itself. The morphology and size of in-stent thrombosis can vary significantly due to the different contributions of the stent and underlying injuries. Additionally, the volume of in-stent thrombosis is affected by the extent of the injury and the viscosity of platelets, showing a notable increase in volume with the lengthening of the injury area and rise in platelet viscosity. This study provides a novel theoretical framework for optimizing stent placement strategies and structural designs by examining the effects of stent struts and associated injuries on thrombus formation.

Left Main Snorkel Stent Thrombosis in Association With Takayasu Arteritis.

Takayasu arteritis (TA) is a rare form of large vessel arteritis that predominantly affects the aorta and its major branches. This inflammation leads to thickening, fibrosis, and stenosis of the arterial walls, which may lead to thrombus formation. The resulting symptoms are typically due to ischemia of the end organs. Coronary artery involvement is uncommon and primarily affects the ostia of the arteries. Ostial involvement of the coronary arteries can have a dramatic course, including fatal outcomes. We present the case of a 16-year-old female with TA involving the ostium of the left main coronary artery, causing severe stenosis. A successful percutaneous coronary intervention was performed on the left main artery with snorkel stent placement, which was complicated by cardiac arrest seven months later due to complete thrombosis of the proximal opening of the protruding stent.

Shunt dysfunction and mortality after transjugular intrahepatic portosystemic shunt (TIPS) in patients with portal hypertension.

OBJECTIVES: Transjugular intrahepatic portosystemic shunt (TIPS) is a catheter-based, minimally invasive procedure to reduce portal hypertension. The aim of the study was to investigate dysfunction and mortality after TIPS and to identify factors associated with these events. METHODS: A retrospective analysis of 834 patients undergoing TIPS implantation in a single center from 1993-2018 was performed. Cumulative incidence curves were estimated, and frailty models were used to assess associations between potentially influential variables and time to dysfunction or death. RESULTS: 1-, 2-, and 5-year mortality rates were 20.9% (confidence interval (CI) 17.7-24.1), 22.5% (CI 19.1-25.8), and 25.0% (CI: 21.1-28.8), 1-year, 2-year, and 5-year dysfunction rates were 28.4% (CI 24.6-32.3), 38.9% (CI 34.5-43.3), and 52.4% (CI 47.2-57.6). The use of covered stents is a protective factor regarding TIPS dysfunction (hazard ratio (HR) 0.47, CI 0.33-0.68) but does not play a major role in survival (HR 0.95, CI 0.58-1.56). Risk factors for mortality are rather TIPS in an emergency setting (HR 2.78, CI 1.19-6.50), a previous TIPS dysfunction (HR 2.43, CI 1.28-4.62), and an increased Freiburg score (HR 1.45, CI 0.93-2.28). CONCLUSION: The use of covered stents is an important protective factor regarding TIPS dysfunction. Whereas previous TIPS dysfunction, emergency TIPS implantation, and an elevated Freiburg score are associated with increased mortality. Awareness of risk factors could contribute to a better selection of patients who may benefit from a TIPS procedure and improve clinical follow-up with regard to early detection of thrombosis/stenosis. CRITICAL RELEVANCE STATEMENT: The use of covered stents reduces the risk of dysfunction after transjugular intrahepatic portosystemic shunt (TIPS). TIPS dysfunction, emergency TIPS placement, and a high Freiburg score are linked to higher mortality rates in TIPS patients. KEY POINTS: The risk of dysfunction is higher for uncovered stents compared to covered stents. Transjugular intrahepatic portosystemic shunt dysfunction increases the risk of instantaneous death after the intervention. A higher Freiburg score increases the rate of death after the intervention. Transjugular intrahepatic portosystemic shunt implantations in emergency settings reduce survival rates.

Temporal Effect of CYP3A4/5 Induction on Ticagrelor's Pharmacodynamic Effects: A Case Series.

Ticagrelor is contraindicated in combination with cytochrome P450 3A4 and 3A5 enzyme (CYP3A4/5) inducers due to increased clearance, causing diminished antiplatelet effects. The emergent nature of acute coronary syndromes (ACS) may preclude scrutinization of home medications before P2Y12 inhibitor administration. The purpose of this case series is to establish the temporal impact of CYP3A4/5 enzyme induction on ticagrelor's pharmacodynamic effect by utilizing VerifyNow platelet aggregation studies. This was a retrospective case series of three patients who were taking a CYP3A4/5-inducing medication and loaded with ticagrelor for ACS. The duration of ticagrelor's antiplatelet effect was dramatically shortened in the presence of background CYP3A4/5 induction. The offset of antiplatelet effect, defined by platelet reactivity units (PRU), was 10-24 hours in the presence of CYP3A4/5 enzyme induction compared to the anticipated 36-48 hours. This was consistent across CYP3A4/5-inducing medications including carbamazepine, phenobarbital, and phenytoin. This study demonstrates rapid return of platelet function after a ticagrelor loading dose in the presence of CYP3A4/5-inducing medications. Monitoring of PRU every 6-12 hours with subsequent loading with clopidogrel or prasugrel should be considered. Larger scale studies are warranted to confirm these results.

Can CYP2C19 genotyping improve antiplatelet therapy efficacy in real-life practice? Recent advances.

Clopidogrel remains the most widely used P2Y12 receptor inhibitor worldwide and is often used in combination with aspirin for secondary prevention in patients with arterial disease. The drug is associated with a wide response variability with one on three patients exhibiting little or no inhibition of adenosine diphosphate-induced platelet aggregation. It is a prodrug that is mainly metabolized by hepatic cytochrome P450 (CYP) 2C19. Patients who carry a CYP2C19 loss-of-function (LoF) allele have reduced metabolism of clopidogrel that is associated with reduced platelet inhibition compared to non-carriers that is associated with increased risk for thrombotic event occurrences, particularly, stent thrombosis. The United States Food and Drug Administration (US FDA) issued a black box warning in the clopidogrel label highlighting the importance of presence of CYP2C19 LOF allele during the insufficient metabolism of clopidogrel and availability of other potent P2Y12 inhibitor for the treatment in CYP2C19 poor metabolizers. Clinical trials have conclusively demonstrated greater anti-ischemic benefits of prasugrel/ticagrelor in the treatment of patients carrying the CYP2C19 LoF allele. However, uniform use of these more potent P2Y12 inhibitors has been associated with greater bleeding and cost, and lower adherence. The latter information provides a strong rationale for personalizing P2Y12 inhibitor therapy based on the laboratory determination of CYP2C19 genotype. However, cardiologists have been slow to take up pharmacogenetic testing possibly due to lack of provider and patient education, clear cardiology guidelines and, and lack of positive results from adequately sized randomized clinical trials. However, current evidence strongly supports genotyping of patients who are candidates for clopidogrel. Physicians should strongly consider performing genetic tests to identify LoF carriers and treat these patients with more pharmacodynamically predictable P2Y12 inhibitors than clopidogrel.

Long-Term Safety and Performance of BioMime™ Morph Sirolimus-Eluting Coronary Stent System for Very Long Coronary Lesions.

Background: The use of multiple overlapping stents for long lesions in tapered coronary arteries has been associated with poor outcomes. This study was conducted to evaluate the 3-year safety and performance of the BioMime™ Morph sirolimus-eluting stent (SES) in very long (length 30 to ≤ 56 mm) coronary lesions in native coronary arteries with a reference vessel diameter of 2.25 to 3.50 mm. Methods: This was a prospective, single-center, observational, real-world, post-marketing surveillance study. Eligible patients were implanted with BioMime™ Morph SES. Patients were followed up at 6, 12, 24, and 36 months. Results: A total of 88 patients were enrolled in the study. The mean age was 58.72 ± 10.10 years and 82.95% were male. Most patients had angina (81.82%) and ischemic heart disease (78.41%), and there was a high prevalence of comorbidities like diabetes mellitus (59.09%), and hypertension (54.55%). A total of 92 long coronary de novo lesions were treated with BioMime™ Morph SES with an average stent length of 45.54 ± 10.20 mm. Device and procedural success rates were 100%. One patient died at 30 days and one case of myocardial infarction was recorded. The cumulative rates of major adverse cardiovascular events (MACEs) at 6, 12, 24, and 36 months were 3.41%, 6.82%, 7.95%, and 7.95%, respectively. There were no cases of stent thrombosis (ST), ischemia-driven target vessel revascularization, or ischemia-driven target lesion revascularization until 36 months of follow-up. Conclusion: BioMime™ Morph SES showed favorable outcomes up to 3 years in treating very long coronary lesions in native coronary arteries, as demonstrated by an acceptable rate of MACEs and absence of ST, based on clinical outcomes up to 3 years.

"Very" Very Late Stent Thrombosis: A Detailed Look at Two Cases.

Although percutaneous coronary intervention (PCI) has radically transformed the scope of treating coronary artery disease with stenting, stent thrombosis (STh) remains a feared complication. Very late STh, a rare complication after PCI, refers to STh occurring greater than one year after post-stent implantation. An even rarer phenomenon, "very" very late stent thrombosis (VVLST), is described in the literature as STh occurring more than five years post-stent implantation. To our knowledge, there are only 10 case reports and one case series describing VVLST. We discuss two additional complex clinical cases of VVLST presenting as ST-elevation myocardial infarction. We highlight epidemiology, pathophysiology, presentation, diagnostic methods, treatment approach, associated complications, and the need for more extensive future work to minimize the risk of VVLST.

Clopidogrel resistance and its relevance: Current concepts.

Clopidogrel is the most widely used P2Y12 receptor inhibitor (P2Y12i) as a part of dual antiplatelet therapy along with aspirin. Clopidogrel is a pro-drug and is metabolized to its active metabolite by the hepatic enzyme cytochrome P4502C19 (CYP2C19). This active metabolite is responsible for the antiplatelet action of clopidogrel. Recent studies have demonstrated that single nucleotide polymorphisms in the CYP2C19 gene, including CYP2C19*2,*3,*4, and *5 alleles, result in reduced production of the active metabolite of clopidogrel, and hence reduced inhibition of platelet aggregation. This in turn enhances the incidence of stent thrombosis and recurrent cardiovascular (CV) events. We report a case of coronary stent thrombosis due to clopidogrel resistance proven by CYP2C19 genotyping. We then review the literature on clopidogrel resistance and its impact on CV outcomes. Subsequently, we discuss the methods of diagnosis of resistance, evidence from clinical trials for tailoring clopidogrel therapy, the role of potent P2Y12 inhibitors, the current guidelines, and future directions.

Neoatherosclerosis: A Distinctive Pathological Mechanism of Stent Failure.

With the development of drug-eluting stents, intimal re-endothelialisation is significantly inhibited by antiproliferative drugs, and stent restenosis transforms from smooth muscle cell proliferation to neoatherosclerosis (NA). As a result of the development of intravascular imaging technology, the incidence and characteristics of NA can be explored in vivo, with some progress made in illustrating the mechanisms of NA. Experimental studies have shed light on the molecular characteristics of NA. More critically, sufficient evidence proves NA as a significant cause of late stent failure. Treatments for NA are still being explored. In this review, we summarise the histopathological characteristics of different types of stent NA, explore the potential relationship of NA with native atherosclerosis and discuss the clinical significance of NA in late stent failure and the promising present and future prevention and treatment strategies.

A patient suffered a second myocardial infarction after a bee sting: a case report.

A few cases have shown that bee stings can be linked to coronary stent thrombosis. However, instances of recurrent myocardial infarction resulting from bee stings among patients who have successfully undergone revascularization treatment are rare. This case report describes a man in his early 60s who experienced an acute myocardial infarction. The left anterior descending coronary artery was revascularized by a drug-eluting stent. Just 1 week later, the patient experienced a second acute myocardial infarction and it occurred immediately after a bee sting. Angiography revealed stent thrombosis so thrombus aspiration was performed. Subsequently, the blood flow in the stent was unobstructed. Follow-up coronary angiography 1 year later revealed no signs of restenosis within the stent. Hymenoptera venoms contains thrombogenic substances that might lead to acute stent thrombosis.

Glycemic Control and Coronary Stent Failure in Patients With Type 2 Diabetes Mellitus.

BACKGROUND: The impact of glycemic control in the risk of stent failure in subjects with type 2 diabetes (T2D) is currently unknown. OBJECTIVES: This study sought to study whether poor glycemic control is associated with a higher risk of stent failure in subjects with T2D. METHODS: This observational study included all patients in Sweden with T2D who underwent implantation of second-generation drug-eluting stents (DES) during 2010 to 2020. The exposure variable was the updated mean of glycated hemoglobin (HbA1c). Individuals were stratified by glycemic control, with HbA1c 6.1% to 7.0% (43-53 mmol/mol) as the reference group. The primary endpoint was the occurrence of stent failure (in-stent restenosis and stent thrombosis). The main result was analyzed in a complete cases model. Sensitivity analyses were performed for missing data and a model with death as a competing risk. RESULTS: The study population consisted of 52,457 individuals (70,453 DES). The number of complete cases was 24,411 (29,029 DES). The median follow-up was 6.4 years. The fully adjusted HR was 1.10 (95% CI: 0.80-1.52) for HbA1c of ≤5.5% (≤37 mmol/mol), 1.02 (95% CI: 0.85-1.23) for HbA1c of 5.6% to 6.0% (38-42 mmol/mol), 1.25 (95% CI: 1.11-1.41) for HbA1c of 7.1% to 8.0% (54-64 mmol/mol), 1.30 (95% CI: 1.13-1.51) for HbA1c of 8.1% to 9.0% (65-75 mmol/mol), 1.46 (95% CI: 1.21-1.76) for HbA1c of 9.1% to 10.0% (76-86 mmol/mol), and 1.33 (95% CI: 1.06-1.66) for HbA1c of ≥10.1% (≥87 mmol/mol). Sensitivity analyses did not change the main result. CONCLUSIONS: We found a significant association between poor glycemic control and a higher risk of stent failure driven by in-stent restenosis.

A Case of Coronary Artery Perforation Caused by Manual Cardiopulmonary Resuscitation in the Catheterization Laboratory.

Cardiopulmonary resuscitation (CPR) is essential for the survival of cardiac arrest patients, but it can cause severe traumatic complications. In the catheterization laboratory, various physical constraints complicate the appropriate performance of CPR. However, we are not aware of reports of CPR complications in this setting. Here, we report a case of coronary artery perforation (CAP) caused by manual CPR in the catheterization laboratory. The patient, a 68-year-old woman, initially underwent successful percutaneous coronary intervention (PCI) for unstable angina. Back in the ward, the patient experienced acute stent thrombosis, which resulted in cardiac arrest, and another PCI was performed under ongoing manual CPR. Although revascularization was successful, sudden CAP occurred, leading to cardiac tamponade. Despite extensive treatment efforts, the patient died 18 hours later.Initially, the compression site of CPR was on the midline of the sternum; however, the compression site shifted to the left, to just above the left anterior descending artery, by the time that CAP was detected via angiography. This corresponded to the area where rib fractures were observed upon computed tomography, suggesting the possibility of traumatic CAP due to manual CPR. The physical constraints in the catheterization laboratory can lead to an inappropriate CPR technique and severe traumatic complications.

The miracle of IVUS for unforeseen stent thrombosis: A case report.

Stent thrombosis is a serious complication with high morbidity and mortality rates resulting in cardiac death or nonfatal myocardial infarction that occurs following stent placement during percutaneous coronary intervention (PCI). Stent underexpansion or malapposition are avoidable risk factors for stent thrombosis. Sufficient postdilation should be considered to mitigate this risk, especially with the guidance of intravascular ultrasound (IVUS). We present the case of a 60-year-old man developing a thrombotic lesion inside a stent 2 weeks after PCI for Non-ST-Segment Elevation Myocardial Infarction (NSTEMI), which was strongly related to stent underexpansion and malapposition. This case highlights the importance of IVUS in evaluating procedural success, particularly in assessing stent expansion and apposition.