Stent thrombosis following bare-metal stent implantation: success of emergency percutaneous coronary intervention and predictors of adverse outcome

Challenges and chances coexist: A visualized analysis and bibliometric study of research on bioresorbable vascular scaffolds from 2000 to 2022

BACKGROUND

Bioresorbable scaffolds (BVS) provide a transient supporting force for blocked vessels and allow them to return to previous physiological characteristics. After verification with twists and turns, it has been acknowledged as an emerging revolution in percutaneous coronary intervention that expresses the current concept of intervention without placement. Through this bibliometric study, we organized the knowledge structure of bioresorbable scaffolds and attempted to predict future research hotspots in this field.

METHODS

seven thousand sixty-three articles were retrieved from the web of science core collection database from 2000 to 2022. Then, we utilize CiteSpace 6.1.R2, Biblioshiny and VOS viewer 1.6.18 to analyze the data visually.

RESULTS

First, according to the spatial analysis, the number of annual publications has shown an approximately increasing trend over the past 2 decades. The USA, the People's Republic of China, and GERMANY published the most articles on bioresorbable scaffolds. Second, SERRUYS P ranked first for his most prolific work and highest cited frequency in this domain. Third, the hotspots in this field can be inferred from the keyword distribution; they were the fabrication technique based on tissue engineering; the factors to be optimized for bioresorbable scaffolds, such as mechanical property, degradation, and implantation; and the common adverse effects of bioresorbable scaffolds, such as thrombosis. Most importantly, in terms of burst detection, we could speculate that cutting-edge technology for manufacturing scaffolds represented by 3D printing constitutes the future hotspots in bioresorbable scaffold development.

CONCLUSION

In the first visualized bibliometric analysis of BVS, we attempt to provide a panoramic view. By enrolling extensive literature, we review the growing trend of BVSs. Since its first introduction, it has been through periods of early prosperity, questioned safety subsequently and the resultantly advanced techniques in recent years. In future, the research should focus on utilizing novel techniques to consummate the manufacturing quality and assure the safety of BVSs.

Vascular remodeling in sheep implanted with endovascular neural interface

Objective.The aim of this work was to assess vascular remodeling after the placement of an endovascular neural interface (ENI) in the superior sagittal sinus (SSS) of sheep. We also assessed the efficacy of neural recording using an ENI.Approach.The study used histological analysis to assess the composition of the foreign body response. Micro-CT images were analyzed to assess the profiles of the foreign body response and create a model of a blood vessel. Computational fluid dynamic modeling was performed on a reconstructed blood vessel to evaluate the blood flow within the vessel. Recording of brain activity in sheep was used to evaluate efficacy of neural recordings.Main results.Histological analysis showed accumulated extracellular matrix material in and around the implanted ENI. The extracellular matrix contained numerous macrophages, foreign body giant cells, and new vascular channels lined by endothelium. Image analysis of CT slices demonstrated an uneven narrowing of the SSS lumen proportional to the stent material within the blood vessel. However, the foreign body response did not occlude blood flow. The ENI was able to record epileptiform spiking activity with distinct spike morphologies.Significance. This is the first study to show high-resolution tissue profiles, the histological response to an implanted ENI and blood flow dynamic modeling based on blood vessels implanted with an ENI. The results from this study can be used to guide surgical planning and future ENI designs; stent oversizing parameters to blood vessel diameter should be considered to minimize detrimental vascular remodeling.

Analysis of Functionalized Ferromagnetic Memory Alloys from the Perspective of Developing a Medical Vascular Implant

Durable biocompatible metal vascular implants are still one of the significant challenges of contemporary medicine. This work presents the preparation of ferromagnetic biomaterials with shape memory in metal strips based on FePd (30 at% Pd) that is either not doped or doped with Ga and Mn, coated with poly(benzofuran-co-arylacetic acid) or polyglutamic acid. The coating of the metal strips with polymers was achieved after the metal surface had been previously treated with open-air cold plasma. The final functionalization was performed to induce anti-thrombogenic/thrombolytic properties in the resulting materials. SEM-EDX microscopy and X-ray photoelectron microscopy (XPS) determined the morphology and composition of the metal strips covered with polymers. In vitro tests of standardized thromboplastin time (PTT) and prothrombin time (PT) were performed to evaluate the thrombogenicity of these biofunctionalized materials for future possible monitoring of the implant in patients.

Some Perspectives on Hypersensitivity to Coronary Stents

The development of coronary stents has represented a revolution in the treatment of coronary heart disease. Beyond their many advantages, stents also have their limitations and complications. Allergic reactions to coronary stents are more common than acknowledged. These stented patients are exposed to foreign substances inserted in direct contact with the coronary intima. Hypersensitivity to stent components and drugs prescribed after stent insertion together with any environmental exposure seem to contribute to these adverse reactions. Patients can present to the hospital with a wide range of symptoms and multiple complications, the most important ones being instent restenosis and stent thrombosis. Although not very common (and not always easy to identify), allergic reactions after coronary or peripheral stents should be taken into account. Careful selection of patients (for elective stent implantation) depending on the propensity to allergies, although hard to achieve, represents a key factor in reducing the number of these complications.

Designing Better Cardiovascular Stent Materials - A Learning Curve

Cardiovascular stents are life-saving devices and one of the top 10 medical breakthroughs of the 21st century. Decades of research and clinical trials have taught us about the effects of material (metal or polymer), design (geometry, strut thickness, and the number of connectors), and drug-elution on vasculature mechanics, hemocompatibility, biocompatibility, and patient health. Recently developed novel bioresorbable stents are intended to overcome common issues of chronic inflammation, in-stent restenosis, and stent thrombosis associated with permanent stents, but there is still much to learn. Increased knowledge and advanced methods in material processing have led to new stent formulations aimed at improving the performance of their predecessors but often comes with potential tradeoffs. This review aims to discuss the advantages and disadvantages of stent material interactions with the host within five areas of contrasting characteristics, such as 1) metal or polymer, 2) bioresorbable or permanent, 3) drug elution or no drug elution, 4) bare or surface-modified, and 5) self-expanding or balloon-expanding perspectives, as they relate to pre-clinical and clinical outcomes and concludes with directions for future studies.

Incidence and In-Hospital Outcomes of Patients Presenting With Stent Thrombosis (from the Japanese Nationwide Percutaneous Coronary Intervention Registry)

Clinical presentation of stent thrombosis (ST) and its sequela under contemporary practice have not been fully elucidated largely due to rare incidence of ST. We sought to assess the characteristics in patients with clinical presentation of ST and their in-hospital outcomes, utilizing nationwide registration system for percutaneous coronary interventions (J-PCI). The present study included acute coronary syndrome (ACS) patients undergoing PCI with clinical findings of definite ST from January 2014 to December 2016. Patients' characteristics, in-hospital mortality and its composite with periprocedural complications were evaluated. Full match comparison was performed. During the study period, 256,610 ACS patients (37.9% of total PCI cases) underwent PCI and 1,367 ST patients (1.9%) were identified from 73,241 ACS patients' records who had a history of previous PCI. Overall, patients with ST were younger but had higher incidence of previous myocardial infarction, compared with those without. In addition, ST patients had increased rate of crude in-hospital death (4.8% vs 1.1%, p <0.001). After full match comparison, the incidence of recurrent ST (post-PCI) was significantly higher in ST patients when compared with ACS patients presenting without ST (4.3% vs 0.9%, p <0.001). Despite younger age, patients with ST had significantly higher incidence of in-hospital mortality and cardiovascular complications, including recurrent ST, compared with those without.

Incidence of cardiac death and recurrent stent thrombosis after treatment for angiographically confirmed stent thrombosis

BACKGROUND

Although many studies showed the predictive factors of stent thrombosis (ST) occurrence, there are few data about clinical outcomes and recurrent ST after percutaneous coronary intervention (PCI) for ST. Furthermore, it is uncertain which factors can cause adverse clinical events including recurrent ST.

METHODS

This study examined the clinical outcomes after treatment for definite ST. Among 18,739 patients between June 2003 and December 2016 who underwent PCI using a drug-eluting stent (DES) or bare-metal stent (BMS), 243 consecutive patients who suffered definite ST were enrolled in this study. The overall incidence of ST was 1.3% (DES 1.4% and BMS 0.8%). The study endpoint was 1-year cardiac death or recurrent definite ST after the initial ST.

RESULTS

Study endpoint occurred in 57 patients (23.5%) during the 1-year follow-up after the initial ST. In multivariate analysis, the factors predicting 1-year endpoint were early ST [adjusted hazard ratio (HR): 2.23, 95% confidence interval (CI): 1.26-4.08, p=0.006], BMS ST (HR: 2.42, 95% CI: 1.27-4.81, p=0.045), serum level of glucose (HR: 1.03, 95% CI: 1.01-1.05, p=0.048), and ST-segment elevation myocardial infarction (STEMI) at the initial ST (HR: 3.73, 95% CI: 1.82-7.65, p<0.001).

CONCLUSIONS

Recurrent ST or cardiac death during the first year after the initial ST event occurred in ∼25% of patients treated for definite ST. BMS ST, serum level of glucose, STEMI, and early ST at the initial ST were associated with adverse cardiac events.

Incidence, angiographic and clinical predictors, and impact of stent thrombosis: a 6-year survey of 6,545 consecutive patients

Objective

We sought to determine the incidence, angiographic predictors, and impact of stent thrombosis (ST).

Background

Given the high mortality after ST, this study emphasises the importance of ongoing efforts to identify angiographic predictors of ST.

Methods

All consecutive patients with angiographically confirmed ST between 2010 and 2016 were 1:4 matched for (1) percutaneous coronary intervention (PCI) indication and (2) index date ±6 weeks to randomly selected controls. Index PCI angiograms were reassessed by two independent cardiologists. A multivariable conditional logistic regression model was built to identify independent predictors of ST.

Results

Of 6,545 consecutive patients undergoing PCI, 55 patients [0.84%, 95% confidence interval (CI) 0.63–1.10%] presented with definite ST. Multivariable logistic regression identified dual antiplatelet therapy (DAPT) non-use as the strongest predictor of ST (odds ratio (OR) 10.9, 95% CI 2.47–48.5, p < 0.001), followed by: stent underexpansion (OR 5.70, 95% CI 2.39–13.6, p < 0.001), lesion complexity B2/C (OR 4.32, 95% CI 1.43–13.1, p = 0.010), uncovered edge dissection (OR 4.16, 95% CI 1.47–11.8, p = 0.007), diabetes mellitus (OR 3.23, 95% CI 1.25–8.36, p = 0.016), and residual coronary artery disease at the stent edge (OR 3.02, 95% CI 1.02–8.92, p = 0.045). ST was associated with increased rates of mortality as analysed by Kaplan-Meier estimates (27.3 vs 11.3%, p_log-rank < 0.001) and adjusted Cox proportional-hazard regression (hazard ratio 2.29, 95% CI 1.03–5.10, p = 0.042).

Conclusions

ST remains a serious complication following PCI with a high rate of mortality. DAPT non-use was associated with the highest risk of ST, followed by various angiographic parameters and high lesion complexity.

Electronic supplementary material

The online version of this article (10.1007/s12471-019-1253-2) contains supplementary material, which is available to authorized users.

Endovascular Metal Devices for the Treatment of Cerebrovascular Diseases

Cerebrovascular disease involves various medical disorders that obstruct brain blood vessels or deteriorate cerebral circulation, resulting in ischemic or hemorrhagic stroke. Nowadays, platinum coils with or without biological modification have become routine embolization devices to reduce the risk of cerebral aneurysm bleeding. Additionally, many intracranial stents, flow diverters, and stent retrievers have been invented with uniquely designed structures. To accelerate the translation of these devices into clinical usage, an in-depth understanding of the mechanical and material performance of these metal-based devices is critical. However, considering the more distal location and tortuous anatomic characteristics of cerebral arteries, present devices still risk failing to arrive at target lesions. Consequently, more flexible endovascular devices and novel designs are under urgent demand to overcome the deficiencies of existing devices. Herein, the pros and cons of the current structural designs are discussed when these devices are applied to the treatment of diseases ranging broadly from hemorrhages to ischemic strokes, in order to encourage further development of such kind of devices and investigation of their use in the clinic. Moreover, novel biodegradable materials and drug elution techniques, and the design, safety, and efficacy of personalized devices for further clinical applications in cerebral vasculature are discussed.

Case Report: INTRAPROCEDURAL STENT THROMBOSIS IN PERCUTANEOUS CORONARY ANGIOPLASTY

Stent thrombosis is a rare complication of PCI but associated with STEMI and sudden cardiac death. Intra procedural stent thrombosis (IPST) was defined new or increasing (compared with baseline) thrombus within or adjacent to a deployed stent occurring the index PCI procedure whether occlusive or nonocclusive. We describe a case with double vessel disease who has complication cardiac arrest and intra procedural stent thrombosis in LAD and Left Main coronary artery after deployed stent in bifurcation LAD-D1. Thrombectomy and rescucitation were performed, and the patient completed her hospital course without complications.

Coronary stents and vascular response to implantation: literature review

Drug-eluting stents (DESs) have minimized the limitations of bare-metal stents (BMSs) after percutaneous coronary interventions. Nevertheless, serious concerns remain about possible late complications of stenting, such as stent thrombosis (ST) and in-stent restenosis (ISR), although the introduction of second-generation DESs seems to have softened the phenomenon, compared to the first-generation ones. ST is a potentially catastrophic event, which has been markedly reduced by optimization of stent implantation, novel stent designs, and dual antiplatelet therapy. The exact mechanism to explain its occurrence is under investigation, and, realistically, multiple factors are responsible. ISR of BMSs has been previously considered as a stable condition with an early peak (at 6 months) of intimal hyperplasia, followed by a regression period beyond 1 year. On the contrary, both clinical and histologic studies of DESs have demonstrated evidence of continuous neointimal growth during long-term follow-up, named "late catch-up" phenomenon. The acknowledgment that ISR is a relatively benign clinical condition has been recently challenged by evidences which reported that patients with ISR can experience acute coronary syndromes. Intracoronary imaging is an invasive technology that allows identifying features of atherosclerotic plaque of stent implanted and of vascular healing after stenting; it is often used to complete diagnostic coronary angiography and to drive interventional procedures. Intracoronary optical coherence tomography is currently considered a state-of-the-art imaging technique; it provides, compared to intravascular ultrasound, better resolution (at least >10 times), allowing the detailed characterization of the superficial structure of the vessel wall. Imaging studies "in vivo," in agreement with histological findings, suggest that chronic inflammation and/or endothelial dysfunction may induce late de novo "neoatherosclerosis" inside both BMSs and DESs. So, neoatherosclerosis has become the prime suspect in the pathogenesis of late stent failure.

Lack of Concordance Between Local Investigators, Angiographic Core Laboratory, and Clinical Event Committee in the Assessment of Stent Thrombosis: Results From the TRACER Angiographic Substudy

BACKGROUND

Stent thrombosis (ST) is an important end point in cardiovascular clinical trials. Adjudication is traditionally based on clinical event committee (CEC) review of case report forms and source documentation rather than angiograms. However, the degree to which this method of adjudication is concordant with the review of independent angiographic core laboratories (ACLs) has not been studied. This report represents the first assessment of variability between local investigators (LIs), a CEC, and an ACL.

METHODS AND RESULTS

Serial angiograms of 329 patients with acute coronary syndrome without ST-segment-elevation who underwent percutaneous coronary intervention at entry in the Trial to Assess the Effects of Vorapaxar in Preventing Heart Attack and Stroke in Particpants With Acute Coronary Syndrome (TRACER) and who met criteria for possible ST subsequent to the index event were reviewed by an ACL. The ACL was blinded to the assessment by both LIs and the CEC regarding the presence or absence of ST. CEC adjudication was based on Academic Research Consortium definitions of ST, using case report form data and source documents, including catheterization laboratory reports. The ACL, CEC, and LIs agreed on the presence or absence of ST in 52.9% events (κ=0.32; 95% confidence interval, 0.26-0.39). The ACL and CEC agreed on 82.7% of events (κ=0.57; 95% confidence interval, 0.47-0.67); the ACL and LIs agreed on 61.1% of events (κ=0.25; 95% confidence interval, 0.16-0.34); and the CEC and LIs agreed on 62% of events (κ=0.28; 95% confidence interval, 0.21-0.36).

CONCLUSIONS

ST reporting by an ACL, a CEC, and LIs is discordant. The assessment of ST is more often detected by direct review of angiograms by an ACL.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00527943.

SUB-ACUTE STENT THROMBOSIS AND IN-STENT RESTENOSIS ASSOCIATED WITH ANTIPLATELETS CLOPIDOGREL RESISTANCE AND PROTEIN S DEFICIENCY

Protein S deficiency and antiplatelets clopidogrel resistance may uncommonly be responsible for coronary artery thrombosis. Hereby we report a patient presented with coronary disease, who had undergone PCI. However, two days later the patient was found in-stent thrombosis. Primary PCI was performed later with good result, but after 4 months evaluation with treadmill test we found significant ST depression in related region. It was suspected the patient had in-stent re-stenosis incidence. Further hematologic investigation showed that this patient had antiplatelets clopidogrel resistance and protein S deficiency. Double antiplatelet with another kind of antiplatelets and anticoagulant had given in this case. However, the remaining consideration is the choice for reperfusion strategy.

Polymers for Cardiovascular Stent Coatings

Polymers have found widespread applications in cardiology, in particular in coronary vascular intervention as stent platforms (scaffolds) and coating matrices for drug-eluting stents. Apart from permanent polymers, current research is focussing on biodegradable polymers. Since they degrade once their function is fulfilled, their use might contribute to the reduction of adverse events like in-stent restenosis, late stent-thrombosis, and hypersensitivity reactions. After reviewing current literature concerning polymers used for cardiovascular applications, this review deals with parameters of tissue and blood cell functions which should be considered to evaluate biocompatibility of stent polymers in order to enhance physiological appropriate properties. The properties of the substrate on which vascular cells are placed can have a large impact on cell morphology, differentiation, motility, and fate. Finally, methods to assess these parameters under physiological conditions will be summarized.

Unanswered questions in patients with concurrent atrial fibrillation and acute coronary syndrome

The best regimen for the long-term management of patients with atrial fibrillation who present with an acute coronary syndrome or require placement of a coronary stent remains unclear. Clinicians need to understand the risk of stroke, stent thrombosis, and major bleeding associated with treating these patients. Numerous studies and risk assessment schemes provide clinicians with an estimation of the risk of stroke, stent thrombosis, and major bleeding that may be associated with the use or avoidance of dual antiplatelet therapy with concurrent anticoagulation therapy (triple therapy). This review discusses the special antithrombotic needs in patients who have atrial fibrillation and either acute coronary syndrome or a requirement for percutaneous coronary intervention, including the published evidence for non-vitamin K oral anticoagulants, and the unanswered questions in this patient population. In conclusion, until the results of additional ongoing or planned randomized trials are known, clinicians must continue to rely on expert opinion and their own clinical judgment when treating these patients.

Contemporary analysis of incidence and outcomes of stent thrombosis presenting as ST elevation myocardial infarction in a primary percutaneous coronary intervention cohort

There are limited data about the effectiveness of primary percutaneous coronary intervention (PPCI) for stent thrombosis treatment. We aimed to evaluate the prevalence and outcomes of PPCI in patients with ST elevation acute myocardial infarction (STEMI) due to stent thrombosis, and comparing the outcomes with patients treated for de novo coronary thrombosis. This was an observational cohort study of 2,935 patients who underwent PPCI from 2003 to 2011 with follow-up for a median of 3.0 years (interquartile range 1.2 to 4.6). The primary end point was the first major adverse cardiac event (MACE) defined as death, nonfatal myocardial infarction, stroke, or target vessel revascularization. Stent thrombosis overall accounted for 6.6% (194 of 2,935) of all STEMIs with a proportion that increased over time (3.3% in 2004 to 9.4% in 2011). A total of 34.5% were early, 30.9% late stent thrombosis, and 34.5% were very late stent thrombosis. Indications for the original intervention were elective in 27.8%, after acute coronary syndrome (non-STEMI or unstable angina) in 21.1%, and after PPCI in 51.1%. Patients with stent thrombosis had higher rates of hypertension, hypercholesterolemia, diabetes, renal dysfunction, and previous myocardial infarction or coronary artery bypass surgery compared with patients with native artery occlusion. MACE rates were higher in patients with stent thrombosis compared with patients with native artery occlusions (40.9%, 95% confidence interval [CI] 31.1 to 50.6 vs 15.1%, 95% CI 12.5 to 18.3; p <0.0001). The poor outcome of stent thrombosis was particularly associated with early and late stent thromboses. Very late stent thrombosis appears to be a relatively less serious event, with similar outcomes to native vessel thromboses (MACE very late stent thrombosis 16.5%, 95% CI 8.2 to 28.6 vs native 15.1%, 95% CI 12.5 to 18.3, p = 0.245). In conclusion, stent thrombosis accounts for an increasing proportion of STEMI and is associated with worse outcomes compared with native artery occlusion.

Long-term safety of drug-eluting stents

Stent implantation in coronary stenosis has revolutionized the treatment of coronary artery disease. The introduction of antirestenotic drug coatings further improved their efficacy in reducing target vessel revascularizations. With increasing use of drug-eluting stents (DES), stent thrombosis (ST) rose as potentially fatal major complication. Initially, the incidence of ST late after stent implantation seemed to be similar for DES and bare metal stents until several studies proved otherwise in first-generation DES. Since then, the design and components of DES have been changed and new polymers, drugs and different combinations of platelet inhibitors have been introduced to further improve the safety of DES. In this review, the authors focus on the relationship between DES, lesion anatomy, implantation technique and pharmacology to avoid the occurrence of ST. Furthermore, the relationship between dual antiplatelet therapy, bleeding rate and its significant impact on patient outcome is discussed. Finally, some promising future concepts are highlighted.

Short-term consequences of angiographically-confirmed coronary stent thrombosis

OBJECTIVES

To conduct a meta-analysis to quantify the real-world incidence of in-hospital or 30-day death or myocardial infarction (MI), and angiographically-confirmed ST-related treatment costs.

BACKGROUND

The short-term clinical and economic consequences of coronary stent thrombosis (ST) are thought to be significant.

METHODS

We searched MEDLINE, Embase and Scopus from January 2000-July 2012 to identify observational/registry studies that evaluated a cohort of ≥ 25 patients experiencing angiographically-confirmed thrombosis of a drug-eluting or bare-metal stent, required the use of dual-antiplatelet therapy for guideline-recommended durations, and reported incidences of in-hospital or 30-day death or MI and/or ST-related treatment costs. Incidences and costs from each study were pooled using random-effects meta-analysis.

RESULTS

Twenty-three studies were included. Of the 13 studies reporting in-hospital outcomes, 12 (N=8,832 STs) reported mortality data, with the pooled incidence rate estimated to be 7.9%, 95%CI=5.4%-11.3%, I(2)=86%. Ten studies (N=1,294 STs) reported 30-day death, with a pooled incidence of 11.6%, 95%CI=8.8%-15.1%, I(2)=55%. Patients experiencing early ST (within 30-days of implant) had higher in-hospital and 30-day mortality than those experiencing very-late ST (interaction p<0.04 for both). Stent type had no significant effect on in-hospital or 30-day mortality. In the 5 studies (N=542 STs) and 3 studies (N=180 STs) reporting in-hospital and 30-day MI, respectively, the pooled incidence rates were 6.1%, 95%CI=2.1%-16.2%, I(2)=88% and 9.5%, 95%CI=3.8%-22.0%, I(2)=65%. One study reported costs associated with ST, estimating the median/patient cost of hospitalization to treat early ST at $11,134 (in 2000US$).

CONCLUSIONS

Regardless of stent type used, the short-term consequences of coronary ST appear significant.

Acute Stent Thrombosis and Heparin Induced Thrombocytopenia in a Patient With ST-Segment Elevation Myocardial Infarction

Heparin is an essential drug in the treatment of acute coronary syndrome and it is used during percutaneous coronary intervention (PCI). Heparin-induced thrombocytopenia (HIT), albeit a serious complication of heparin therapy characterized by thrombocytopenia and high risk for venous and arterial thrombosis, has rarely been previously reported during PCI. We report a case of an acute stent thrombosis due to an unusual cause, HIT during primary PCI, in a patient with acute myocardial infarction.

Chronic kidney disease and the risk of stent thrombosis after percutaneous coronary intervention with drug-eluting stents

BACKGROUND

Chronic kidney disease (CKD) has been demonstrated to be associated with adverse clinical outcomes for patients with coronary artery disease (CAD). However, data on relation of CKD and stent thrombosis (ST) after drug-eluting stent (DES) implantation are limited.

OBJECTIVES

This study was designed to examine whether CKD is associated with higher incidence of ST after elective coronary DES implantation compared with patients with normal renal function.

METHODS

We consecutively enrolled 2,862 patients undergoing elective percutaneous coronary intervention (PCI) with DES. Demographic and clinical data were collected preoperatively. CKD was defined as estimated glomerular filtration rate (eGFR) < 60 ml/min, calculated using the modified MDRD equation. The primary outcome was 1-year definite or probable ST.

RESULTS

Four hundred and forty-five participants (15.5%) had CKD before procedure. The incidence of 1-year definite or probable ST was significantly higher in CKD patients compared with patients with normal renal function (1.8% vs. 0.6%, P = 0.014). After adjustment for multiple clinical and biochemical covariates, CKD was an independent predictor of 1-year definite or probable ST (hazard rate [HR] 0.396, 95% CI 0.165-0.951, P = 0.038).

CONCLUSION

CKD is significantly associated with increased incidence of 1-year definite or probable ST in patients undergoing PCI with DES.

Patient-specific factors relating to medication adherence in a post-percutaneous coronary intervention cohort

OBJECTIVE

To explore the association between medication adherence and qualitatively characterised patient-specific themes relating to medication adherence in patients following percutaneous coronary intervention (PCI).

METHODS

Data-collection questionnaires and qualitative topic guides were piloted in two patients. A validated questionnaire generated an adherence score for a convenience sample of 20 patients within 7 days of PCI. Semi-structured qualitative interviews were subsequently carried out with all patients to explore patient-specific themes relating to measured medication adherence.

KEY FINDINGS

Fourteen out of 20 patients (70%) had scores indicative of good adherence. Key factors associated with good adherence included having a good relationship with the doctor, having an understanding of the condition, knowledge of the indications and consequences of non-adherence, perceived health benefits and medications eliciting tangible symptom control. There were misconceptions of concern regarding adverse drug reactions and the importance of aspirin, both of which had a negative effect on adherence. The role of the community pharmacist was sometimes, although not always, misunderstood.

CONCLUSION

This study suggests there is an association between patients' beliefs, knowledge, understanding and misconceptions about medication and their adherence in a post-PCI cohort. To optimise medication adherence it is vital for prescribers to remain patient-focused and cognisant of patient-specific themes relating to medication adherence.

Platelet function profile post-clopidogrel therapy in patients with type 2 diabetes undergoing coronary stent implantation

Platelet dysfunction contributes to the increased risk of thromboischemic complications after percutaneous coronary intervention (PCI), particularly in type 2 diabetes. Little is known about the effects of glycemic control on platelet reactivity. We assessed adenosine diphosphate-induced platelet aggregation and flow cytometric expression of P-selectin in 90 patients (56 diabetic and 34 nondiabetic patients) undergoing coronary stent implantation after administration of clopidogrel as a potential predictor of poststent complications and its relation to glycemic control. Posttreatment platelet reactivity was significantly elevated in diabetic compared with nondiabetic participants and was associated with smoking, hypercholesterolemia, overweight, and cardiovascular ischemic events. A linear relationship was found between hemoglobin A1c in diabetic patients and platelet reactivity. Both methods (standard aggregometry and P-selectin expression) used for assessment of platelet function were positively correlated. Low responsiveness to clopidogrel detected by posttreatment platelet reactivity is a risk factor for ischemic events after PCI in diabetic patients.

[Decreasing incidence of stent thrombosis]

Stent thrombosis (ST) remains a major pitfall of stent implantation in contemporary percutaneous coronary intervention (PCI) leading to high rates of death and non-fatal myocardial infarction. Many predictors of ST have been reported worldwide but the strongest have to be highlighted regarding the catastrophic prognosis of such an event. Because platelet aggregation has a pivotal role in ST pathogenesis, the new antiplatelet regimens combining aspirin and P2Y12 receptor inhibitors have led to a remarkable decrease in the ST incidence, especially in the setting of acute coronary syndrome (ACS). In this article, our purpose is to review the evolution of ST incidence since first stent use in PCI. We will also overview the main predictors of ST focusing on ACS and clopidogrel low response.

Duration of dual antiplatelet therapy after percutaneous coronary intervention with drug-eluting stent implantation: a review of the current guidelines and literature

Dual antiplatelet therapy is the mainstay of medical treatment after percutaneous coronary intervention regarding the risk of stent thrombosis occurrence. Since the beginning of the stenting era, antiplatelet regimens have evolved according to the emerging and widespread diffusion of new devices and more challenging indications for their use. In the past years, concerns have been raised about the safety of drug-eluting stent implantation with regard to late and very late stent thrombosis. Thus, the length of dual antiplatelet therapy has been progressively increased with marked individual and local differences. However, prolonged antiplatelet therapy leads to increased risk of bleeding, especially in the setting of surgical procedures, traumas, and/or other diseases. To date, the exact duration of dual antiplatelet therapy after drug-eluting stent implantation is still debated in the literature. The aim of this article is to review the literature and the current guidelines on the risks and benefits of pursuing dual antiplatelet therapy after percutaneous coronary intervention with drug-eluting stent implantation.

Acute stent thrombosis during percutaneous coronary intervention. Treatment with tirofiban

Although rarely reported, acute instent thrombosis can be life threatening, especially in cases where there are no ST segment changes. For this reason, careful history taking, follow-up, and prompt coronary angiography may be lifesaving. Herein, a case of acute stent thrombosis with no ST segment changes on electrocardiogram that was resolved with intracoronary tirofiban is presented.

Consensus document: antithrombotic therapy in patients with atrial fibrillation undergoing coronary stenting. A North-American perspective

The optimal regimen of the anticoagulant and antiplatelet therapies in patients with atrial fibrillation who have had a coronary stent is unclear. It is well recognised that "triple therapy" with aspirin, clopidogrel, and warfarin is associated with an increased risk of bleeding. National guidelines have not made specific recommendations given the lack of adequate data. In choosing the best antithrombotic options for a patient, consideration needs to be given to the risks of stroke, stent thrombosis and major bleeding. This document describes these risks, provides specific recommendations concerning vascular access, stent choice, concomitant use of proton-pump inhibitors and the use and duration of triple therapy following stent placement based upon the risk assessment.

Point-of-care platelet function testing in patients undergoing PCI: between a rock and a hard place

Since recent studies have linked an impaired response to antiplatelet therapy with a higher incidence of atherothrombotic events, the monitoring of the efficacy of antiplatelet therapy in the individual patient has attracted much attention. In the present report, we demonstrate that platelet function testing with several point-of-care assays results in ambiguous and conflicting results: some assays indicated that the patient's platelets were insufficiently inhibited by clopidogrel whereas other assays reported an adequate response. Therefore, platelet function assays should not be used solely to guide treatment decisions, and tailor-made antithrombotic treatment has to wait for the most predictive platelet function test to emerge for measuring the risk for thrombotic complications after stenting. Until then, daily clinical practice should not be guided by point-of-care platelet function testing. (Neth Heart J 2007;15:299-305.).

Post myocardial infarction cardiogenic shock: a review of current therapies

Cardiogenic shock is often a devastating consequence of acute myocardial infarction (MI) and portends to significant mortality and morbidity. Despite improvements in expediting the time to treatment and enhancements in available medical therapy and reperfusion techniques, cardiogenic shock remains the most common cause of mortality following MI. Post-MI cardiogenic shock most commonly occurs as a consequence of severe left ventricular dysfunction. Right ventricular (RV) MI must also be considered. Mechanical complications including acute mitral regurgitation, ventricular septal rupture, and ventricular free-wall rupture can also lead to cardiogenic shock. Rapid diagnosis of cardiogenic shock and its underlying cause is pivotal to delivering definitive therapy. Intravenous vasoactive agents and mechanical support devices may temporize the patient's hemodynamic status until definitive therapy by percutaneous or surgical intervention can be performed. Despite prompt management, post-MI cardiogenic shock mortality remains high.

Fibrinolytic therapy for very late stent thrombosis--is it a viable option?

Stent thrombosis (ST) has a very high case fatality and morbidity rates. The risk of very late ST is significantly increased with drug-eluting stents (DES) compared to bare-metal stents for at least up to 4 years. Discontinuation of clopidogrel therapy is the single most important consistently identified risk factor. Immediate reperfusion, preferably by primary percutaneous coronary intervention (PCI), has been considered the therapy of choice. Compared to de novo ST-elevation myocardial infarction (STEMI), myocardial infarction (MI) related to ST has significantly higher major adverse cardiovascular events (MACE) and lower reperfusion rates. Due to the significantly higher mortality associated with STEMI due to ST, prompt revascularization assumes paramount significance. Our case reflects the potential utility of fibrinolytic therapy for STEMI due to very late ST. Systemic fibrinolysis should be considered for ST in the presence of ongoing significant ischemia and unavailability of prompt PCI.

Prevention of the renarrowing of coronary arteries using drug-eluting stents in the perioperative period: an update

The management of patients scheduled for surgery with a coronary stent, and receiving 1 or more antiplatelet drugs, has many controversies. The premature discontinuation of antiplatelet drugs substantially increases the risk of stent thrombosis (ST), myocardial infarction, and cardiac death, and surgery under an altered platelet function could also lead to an increased risk of bleeding in the perioperative period. Because of the conflict in the recommendations, this article reviews the current antiplatelet protocols after positioning a coronary stent, the evidence of increased risk of ST associated with the withdrawal of antiplatelet drugs and increased bleeding risk associated with its maintenance, the different perioperative antiplatelet protocols when patients are scheduled for surgery or need an urgent operation, and the therapeutic options if excessive bleeding occurs.

Angiographic predictors of recurrent stent thrombosis (from the Outcome of PCI for stent-ThrombosIs MultIcentre STudy [OPTIMIST])

Stent thrombosis is a catastrophic occurrence burdened by a high mortality rate and a tendency to recur. We sought to evaluate the angiographic risk factors for recurrent stent thrombosis (rST) in a subpopulation of 91 Outcome of PCI for stent-ThrombosIs Multicenter STudy (OPTIMIST) patients who underwent quantitative angiographic evaluation by an independent core laboratory. The Academic Research Consortium criteria were used for rST adjudication. A multivariate Cox proportional hazards model was applied to estimate the hazard ratios and the corresponding 95% confidence intervals for the occurrence of Academic Research Consortium-defined, definite rST (primary end point), definite or probable rST (secondary end point), and definite or probable or possible rST (secondary end point). A total of 8 definite rST events occurred during a median follow-up of 244 days (range 165 to 396), of which 5 were early and 3 were late. In the multivariate model, a residual thrombus score of > or =3 (hazard ratio 6.5, 95% confidence interval 1.4 to 30.7, p = 0.017) and a larger postprocedural reference vessel diameter (hazard ratio 4.5, 95% confidence interval 1.5 to 13.3, p = 0.006) were significantly associated with the primary end point. When the same model was applied to the 15 definite and probable rST events, only a residual thrombus score of > or =3 (hazard ratio 7.8, 95% confidence interval 2.5 to 24.5, p <0.001) was significantly associated with rST. Finally, when possible rST events were included (18 patients), a residual thrombus score of > or =3 remained associated with the dependent variable (hazard ratio 6.1, 95% confidence interval 2.0 to 18.2, p = 0.001), along with a larger postprocedural reference vessel diameter. In conclusion, when performing percutaneous coronary intervention for stent thrombosis, the residual thrombus burden and larger reference vessel were potent risk factors for rST.

A history of late and very late stent thrombosis is not associated with increased activation of the contact system, a case control study

BACKGROUND

The pathophysiological pathways resulting in Late Stent Thrombosis (LST) remain uncertain. Findings from animal studies indicate a role of the intrinsic coagulation pathway in arterial thrombus formation, while clinical studies support an association with ischemic cardiovascular disease. It is currently unknown whether differences in the state of the contact system might contribute to the risk of LST or Very Late Stent Thrombosis (VLST). We assessed the relation between levels of several components involved in the contact system and a history of LST and VLST, termed (V)LST in a cohort of 20 patients as compared to a matched control group treated with PCI.

METHODS AND RESULTS

Activated factor XII (FXIIa), FXII zymogen (FXII), FXIIa-C1-esterase inhibitor (C1-inhibitor), Kallikrein-C1-inhibitor, FXIa-C1-inhibitor and FXIa-alpha1-antitrypsin (AT-inhibitor) complexes were measured by Enzyme-linked immunosorbent assy (ELISA) methodology.Cases and controls showed similar distributions in sex, age, baseline medications and stent type. Patients with a history of (V)LST had a significantly greater stent burden and a higher number of previous myocardial infarctions than the control patients.There were no significant between-group differences in the plasma levels of the components of the contact system.

CONCLUSION

In a cohort of patients with a history of (V)LST, we did not observe differences in the activation state of the intrinsic coagulation system as compared to patients with a history of percutaneous coronary intervention without stent thrombosis.