Safety and efficacy of antiplatelet and antithrombotic therapy in acute coronary syndrome patients with chronic kidney disease

Medical Management of Coronary Artery Disease in Patients with Chronic Kidney Disease

Chronic kidney disease patients are at increased risk of cardiovascular disease, which is the leading cause of mortality among this population. In addition, chronic kidney disease is a major risk factor for the development of coronary artery disease and is widely regarded as a coronary artery disease risk equivalent. Medical therapy is the cornerstone of coronary artery disease management in the general population. However, there are few trials to guide medical therapy of coronary artery disease in chronic kidney disease, with most data extrapolated from clinical trials of mainly non-chronic kidney disease patients, which were not adequately powered to evaluate this subgroup. There is some evidence to suggest that the efficacy of certain therapies such as aspirin and statins is attenuated with declining estimated glomerular filtration rate, with questionable benefit among end-stage renal disease (ESRD) patients. Furthermore, chronic kidney disease and ESRD patients are at higher risk of potential side effects with therapy, which may limit their use. In this review, we summarize the available evidence supporting the safety and efficacy of medical therapy of coronary artery disease in chronic kidney disease and ESRD patients. We also discuss the data on new emerging therapies, including PCSK9i, SGLT2i, GLP1 receptor agonists, and nonsteroidal mineralocorticoid receptor antagonists, which show promise at reducing risk of cardiovascular events in the chronic kidney disease population and may offer additional treatment options. Overall, dedicated studies directly evaluating chronic kidney disease patients, particularly those with advanced chronic kidney disease and ESRD, are greatly needed to establish the optimal medical therapy for coronary artery disease and improve outcomes in this vulnerable population.

Ferroptosis of Endothelial Cells Triggered by Erythrophagocytosis Contributes to Thrombogenesis in Uremia

BACKGROUND

Although thrombosis events are the leading complication of uremia, their mechanism is largely unknown. The interaction between endothelial cells (ECs) and red blood cells (RBCs) in uremic solutes and its prothrombotic role need to be investigated.

METHODS AND RESULTS

Here, we established an in vitro co-incubation model of uremic RBC and EC as well as a uremic rat model induced by adenine. Using flow cytometry, confocal microscopy, and electron microscopy, we found increased erythrophagocytosis by EC accompanied by increased reactive oxygen species, lipid peroxidation, and impairment of mitochondria, indicating that ECs undergo ferroptosis. Further investigations showed increased proteins' expression of heme oxygenase-1 and ferritin and labile iron pool accumulation in EC, which could be suppressed by deferoxamine (DFO). The ferroptosis-negative regulators glutathione peroxidase 4 and SLC7A11 were decreased in our erythrophagocytosis model and could be enhanced by ferrostatin-1 or DFO. In vivo, we observed that vascular EC phagocytosed RBC and underwent ferroptosis in the kidney of the uremic rat, which could be inhibited by blocking the phagocytic pathway or inhibiting ferroptosis. Next, we found that the high tendency of thrombus formation was accompanied by erythrophagocytosis-induced ferroptosis in vitro and in vivo. Importantly, we further revealed that upregulated TMEM16F expression mediated phosphatidylserine externalization on ferroptotic EC, which contributed to a uremia-associated hypercoagulable state.

CONCLUSION

Our results indicate that erythrophagocytosis-triggered ferroptosis followed by phosphatidylserine exposure of EC may play a key role in uremic thrombotic complications, which may be a promising target to prevent thrombogenesis of uremia.

Efficacy and Safety of the Reduced Bivalirudin in Patients Undergoing Coronary Angiography or Percutaneous Coronary Intervention Stratified by Renal Function (REDUCE BOLUS): A Single-Blind, Stratified Randomized, Non-inferiority Trial

Background

In clinical practice, some cases indicated that the loading dose of bivalirudin increased the bleeding risk, particularly in patients with renal insufficiency. Therefore, this study aimed to assess the efficacy and safety of the low-dose (80%) bolus injection of bivalirudin in patients undergoing cardiac catheterization stratified by renal function.

Methods

A total of 204 individuals in the REDUCE BOLUS trial were stratified 1:1 to the estimated glomerular filtration rate (eGFR) ≥ 60 ml/min cohort or eGFR < 60 ml/min cohort, then randomized 1:1 to the reduced bolus bivalirudin group (i.e., the experimental group) or normal bolus bivalirudin group (i.e., the control group), respectively. The primary end point was to compare the differences of the area under the curve of activated clotting time (ACT) between the two groups. The secondary end points were the postoperative net adverse clinical events (NACEs) before discharge, defined as the all-cause mortality, recurrent myocardial infarction, ischemia-driven target vessel revascularization, stroke, and bleeding events.

Results

Between January 3, 2020, and March 26, 2021, 204 patients undergoing coronary angiography were randomly assigned, including 102 (i.e., 51 in the control group and 51 in the experimental group) with normal eGFR and 102 (i.e., 51 control and 51 experimental) with abnormal eGFR. No difference was observed in the curve of ACT between the control group and the experimental group (0.55 ± 0.09 vs. 0.56 ± 0.08, P = 0.542 and 0.55 ± 0.06 vs. 0.57 ± 0.05, P = 0.075, respectively, for normal eGFR cohort and abnormal eGFR cohort). The one-sided 97.5% lower confidence bound for the difference in the area under the ACT curve was –0.017 and 0.0015 in eGFR ≥ 60 ml/min and eGFR<60 ml/min cohort, respectively, both above the preset non-inferiority criterion of -0.07, establishing the non-inferiority. There was no incidence of NACE and stent thrombosis before discharge in each group.

Conclusion

In patients undergoing cardiac catheterization, the efficacy and safety of the reduced bolus of bivalirudin were non-inferior to the normal one, even in patients without chronic kidney disease.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [NCT03588611].

Effects of Bivalirudin and Unfractionated Heparin on Liver and Renal Function in Chinese Patients with Coronary Artery Disease Undergoing Coronary Angiography with/without Percutaneous Coronary Intervention

BACKGROUND AND AIMS

Unfractionated heparin (UFH) and bivalirudin are widely used as anticoagulants in cardiovascular medicine, including for thrombosis prevention during coronary angiography (CAG) and percutaneous coronary intervention (PCI). Little is known of the effects of UFH and bivalirudin on liver and kidney function in patients subjected to these procedures. This study compared the effects of bivalirudin and UFH on liver/renal function in patients with coronary artery disease who underwent CAG, with or without PCI.

METHODS

The study comprised 134 consecutive patients (40-89 years-old), who underwent CAG (or CAG and PCI); among them, 66 and 68 patients were subject to, respectively, bivalirudin or UFH. The following indicators of liver/renal function were measured before and after the procedures: plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen, estimated glomerular filtration rate (eGFR), creatinine clearance, and serum creatinine. Patients were further stratified by severity of chronic kidney disease (CKD), based on original eGFR.

RESULTS

Relative to baseline, in the bivalirudin group, ALT and AST were higher after CAG (p=0.005, 0.025), while blood urea nitrogen and serum creatinine were lower (p=0.049, <0.001). In the UFH group, ALT, AST, eGFR, and creatinine clearance were lower after CAG (p≤0.001, all). Patients given bivalirudin with moderate or severe CKD, but not those with mild CKD, gained significant improvement in kidney function.

CONCLUSIONS

Relative to UFH, bivalirudin may better safeguard the renal function of patients with coronary artery disease who undergo CAG, especially patients with moderate-to-severe renal insufficiency. UFH may cause less liver damage than bivalirudin.

Long-Term Antithrombotic Therapy and Clinical Outcomes in Patients with Acute Coronary Syndrome and Renal Impairment: Insights from EPICOR and EPICOR Asia

BACKGROUND

Information is lacking on long-term management of patients with acute coronary syndrome (ACS) and chronic kidney disease (CKD) (estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m²).

OBJECTIVES

Our objectives were to describe antithrombotic management patterns and outcomes in patients with ACS with varying renal function from the EPICOR (long-tErm follow-uP of antithrombotic management patterns In acute CORonary syndrome patients; NCT01171404) and EPICOR Asia (NCT01361386) studies.

METHODS

EPICOR and EPICOR Asia were prospective observational studies of patients who survived hospitalization for ACS and were enrolled at discharge in 28 countries across Europe, Latin America, and Asia. The studies were conducted from 2010 to 2013 and from 2011 to 2014, respectively. This analysis evaluated patient characteristics and oral antithrombotic management patterns and outcomes up to 2 years post-discharge according to admission eGFR: ≥ 90, 60-89, 30-59, or < 30 mL/min/1.73 m².

RESULTS

Among 22,380 patients with available data, eGFR < 60 mL/min/1.73 m² was observed in 16.7%. Patients with poorer renal function were older, were at greater cardiovascular risk, and had more prior cardiovascular disease and bleeding. Patients with CKD underwent fewer cardiovascular interventions and had more in-hospital cardiovascular and bleeding events. Dual antiplatelet therapy was less likely at discharge in patients with eGFR < 30 (82.3%) than in those with ≥ 90 (91.3%) mL/min/1.73 m² and declined more sharply during follow-up in patients with low eGFR (p < 0.0001). An adjusted proportional hazards model showed that patients with lower eGFR levels had a higher risk of cardiovascular events and bleeding.

CONCLUSIONS

The presence of CKD in patients with ACS was associated with less aggressive cardiovascular management and an increased risk of cardiovascular events.

Epac-1/Rap-1 signaling pathway orchestrates the reno-therapeutic effect of ticagrelor against renal ischemia/reperfusion model

Despite the renal expression of P₂Y₁₂, the purinergic receptor for adenosine diphosphate, few data are available to discuss the renotherapeutic potential of ticagrelor, one of its reversible blockers. Indeed, the tonic inhibitory effect of this receptor has been linked to the activation of exchange protein activated by cyclic adenosine monophosphate-1 (Epac-1) protein through the cyclic adenosine monophosphate cascade. Epac-1 is considered a crossroad protein, where its activation has been documented to manage renal injury models. Hence, the current study aimed to investigate the possible therapeutic effectiveness of ticagrelor, against renal ischemia/reperfusion (I/R) model with emphasis on the involvement of Epac-1 signaling pathway using R-CE3F4, a selective Epac-1 blocker. Accordingly, rats were randomized into four groups; viz., sham-operated, renal I/R, I/R post-treated with ticagrelor for 3 days, and ticagrelor + R-CE3F4. Treatment with ticagrelor ameliorated the I/R-mediated structural alterations and improved renal function manifested by the reduction in serum BUN and creatinine. On the molecular level, ticagrelor enhanced renal Epac-1 mRNA expression, Rap-1 activation (Rap-1-GTP) and SOCS-3 level. On the contrary, it inhibited the protein expression of JAK-2/STAT-3 hub, TNF-α and MDA contents, as well as caspase-3 activity. Additionally, ticagrelor enhanced the protein expression/content of AKT/Nrf-2/HO-1 axis. All these beneficial effects were obviously antagonized upon using R-CE3F4. In conclusion, ticagrelor reno-therapeutic effect is partly mediated through modulating the Epac-1/Rap-1-GTP, AKT/Nrf-2/HO-1 and JAK-2/STAT-3/SOCS-3 trajectories, pathways that integrate to afford novel explanations to its anti-inflammatory, anti-oxidant, and anti-apoptotic potentials.

Kidney transplantation and cardiomyopathy: Concepts and controversies in clinical decision-making

Increasing comorbidities and an aging population have led to a tremendous increase in the burden of both kidney and cardiac dysfunction. Concomitant cardiomyopathy exposes the patients with kidney disease to further physiological, hemodynamic, and pathologic alterations. Kidney transplantation imposes lesser anesthetic and surgical complexities compared to another solid organ transplant. The surgical decision-making remains an unsettled issue in these conditions. The surgical choices, techniques, and sequences in kidney transplant and cardiac surgery depend on the pathophysiological perturbations and perioperative outcomes. The absence of randomized controlled trials eludes us from suggesting definite management protocol in patients with end-stage kidney disease with cardiomyopathy. Nevertheless, in this review, we extracted data from published literature to understand the pathophysiologic interactions between end-stage renal diseases with cardiomyopathy and also proposed the management algorithm in this challenging scenario. The proposed management algorithm would ensure consensus across all stakeholders involved in decision-making. Our simplistic evidence-based approach would augur future randomized trials and would further ensure refinement in our management approach after the emergence of more definitive evidence.

Association Between Low-Molecular-Weight Heparin and Risk of Bleeding Among Hemodialysis Patients: A Retrospective Cohort Study

Background:

Low-molecular-weight heparins (LMWH) replaced unfractionated heparin (UFH) in multiple indications. Although LMWH efficacy in hemodialysis was demonstrated through multiple studies, their safety remains controversial. The potential bioaccumulation in patients undergoing chronic hemodialysis raised the question of bleeding risk among this population.

Objective:

The aim of this study was to evaluate bleeding risk among patients with chronic hemodialysis receiving LMWH or UFH for the extracorporeal circuit anticoagulation.

Design:

We conducted a retrospective cohort study on data extracted from the Régie de l’assurance maladie du Québec (RAMQ) and Med-Echo databases from January 2007 to March 2013.

Setting:

Twenty-one hemodialysis centers in the province of Québec, Canada.

Patients:

Chronic hemodialysis patients.

Measurements:

Bleeding risk evaluated by proportional Cox model for time-dependent exposure using demographics, comorbidities, and drug use as covariates.

Methods:

Minor, major, and total bleeding events identified using International Classification of Diseases, Ninth Revision (ICD-9)/International Classification of Diseases, Tenth Revision (ICD-10) codes in the RAMQ and Med-Echo databases. Exposure status to LMWH or UFH was collected through surveys at the facility level.

Results:

We identified 5322 prevalent and incident patients with chronic hemodialysis. The incidence rate for minor, major, and total bleeding was 9.45 events/1000 patient-year (95% confidence interval [CI]: 7.61-11.03), 24.18 events/1000 patient-year (95% CI: 21.52-27.08), and 32.88 events/1000 patient-year (95% CI: 29.75-36.26), respectively. We found similar risks of minor adjusted hazard ratio (HR: 1.04; 95% CI: 0.68-1.61), major (HR: 0.83; 95% CI: 0.63-1.10), and total bleeding (HR: 0.90; 95% CI: 0.72-1.14) when comparing LMWH with UFH.

Limitations:

Potential misclassification of patients’ exposure status and possible underestimation of minor bleeding risk.

Conclusion:

LMWH was not associated with a higher minor, major, or total bleeding risk. LMWH did not increase the risk of bleeding compared with UFH for the extracorporeal circuit anticoagulation in hemodialysis. The convenience of use and predictable effect made LMWH a suitable alternative to UFH in hemodialysis.

Efficacy and safety of bivalirudin in coronary artery disease patients with mild to moderate chronic kidney disease: Meta-analysis

BACKGROUND

Patients with chronic kidney disease (CKD) have elevated bleeding and ischemic outcomes. We aim to assess the short- and long-term efficacy and safety of bivalirudin compared to heparin plus glycoprotein IIb/IIIa inhibitors (GPIs) in coronary artery disease (CAD) patients with CKD.

METHODS

Randomized trials were searched in PubMed, Cochrane, and Embase databases up to January 2017. Among the trials retrieved, efficacy endpoints were defined as mortality, myocardial infarction (MI), repeat revascularization, stent thrombosis, and major adverse cardiac events (MACEs). Safety endpoints were reported as non-coronary artery bypass grafting (CABG) related major bleeding and thrombolysis in myocardial infarction (TIMI) major bleeding. Risk ratio (RR) and 95% confidence interval (CI) were calculated for each outcome using a fixed effect model.

RESULTS

Five studies with a total of 3796 patients were included. In short-term follow up (30 days), bivalirudin significantly reduced non-CABG related major bleeding (p=0.0004) and TIMI major bleeding (p=0.007) compared to heparin plus GPIs. No significant differences were observed in rates of mortality, MI, repeat revascularization, stent thrombosis, and MACEs between the two groups in short- and long-term follow up (6 months to 3 years). In patients with ST elevated myocardial infarction (STEMI) with concurrent CKD, the decreased non-CABG related major bleeding (p=0.04) without increasing ischemic events was also observed after short-term follow up.

CONCLUSIONS

(1) Bivalirudin is safer than and as effective as heparin plus GPIs in CAD patients with CKD. (2) Impaired renal function does not affect the safety benefits of bivalirudin. (3) Similar efficacy profiles were identified between the two groups after both short- and long-term follow up in the CAD patients with CKD.

Targeting STUB1-tissue factor axis normalizes hyperthrombotic uremic phenotype without increasing bleeding risk

Chronic kidney disease (CKD/uremia) remains vexing because it increases the risk of atherothrombosis and is also associated with bleeding complications on standard antithrombotic/antiplatelet therapies. Although the associations of indolic uremic solutes and vascular wall proteins [such as tissue factor (TF) and aryl hydrocarbon receptor (AHR)] are being defined, the specific mechanisms that drive the thrombotic and bleeding risks are not fully understood. We now present an indolic solute-specific animal model, which focuses on solute-protein interactions and shows that indolic solutes mediate the hyperthrombotic phenotype across all CKD stages in an AHR- and TF-dependent manner. We further demonstrate that AHR regulates TF through STIP1 homology and U-box-containing protein 1 (STUB1). As a ubiquitin ligase, STUB1 dynamically interacts with and degrades TF through ubiquitination in the uremic milieu. TF regulation by STUB1 is supported in humans by an inverse relationship of STUB1 and TF expression and reduced STUB1-TF interaction in uremic vessels. Genetic or pharmacological manipulation of STUB1 in vascular smooth muscle cells inhibited thrombosis in flow loops. STUB1 perturbations reverted the uremic hyperthrombotic phenotype without prolonging the bleeding time, in contrast to heparin, the standard-of-care antithrombotic in CKD patients. Our work refines the thrombosis axis (STUB1 is a mediator of indolic solute-AHR-TF axis) and expands the understanding of the interconnected relationships driving the fragile thrombotic state in CKD. It also establishes a means of minimizing the uremic hyperthrombotic phenotype without altering the hemostatic balance, a long-sought-after combination in CKD patients.

Antithrombotic therapy in end-stage renal disease

The delicate balance of risk vs. benefit of using antiplatelet and antithrombotic agents in the general population is well established. The decision to use these agents in the end stage renal disease (ESRD) population remains complex and difficult. The concomitant association of a prothombotic state with high risk of bleeding in the ESRD population requires individualization and careful clinical judgment before implementing such therapy. There remains a paucity of clinical trials and lack of substantial evidence in literature for safe and effective use of antithrombotic drugs in patients with advanced chronic kidney disease. The current review summarizes the pros and cons of using antiplatelet and antithrombotic agents in primary and secondary prevention of cardiovascular events, evaluate the risks with routine use of anticoagulation for cerebrovascular stroke prevention with nonvalvular atrial fibrillation and role of newer oral anticoagulants as alternate agents in the dialysis population.

Applying the Cell-Based Coagulation Model in the Management of Critical Bleeding

The cell-based coagulation model was proposed 15 years ago, yet has not been applied commonly in the management of critical bleeding. Nevertheless, this alternative model may better explain the physiological basis of current coagulation management during critical bleeding. In this article we describe the limitations of the traditional coagulation protein cascade and standard coagulation tests, and explain the potential advantages of applying the cell-based model in current coagulation management strategies. The cell-based coagulation model builds on the traditional coagulation model and explains many recent clinical observations and research findings related to critical bleeding unexplained by the traditional model, including the encouraging results of using empirical 1:1:1 fresh frozen plasma:platelets:red blood cells transfusion strategy, and the use of viscoelastic and platelet function tests in patients with critical bleeding. From a practical perspective, applying the cell-based coagulation model also explains why new direct oral anticoagulants are effective systemic anticoagulants even without affecting activated partial thromboplastin time or the International Normalized Ratio in a dose-related fashion. The cell-based coagulation model represents the most cohesive scientific framework on which we can understand and manage coagulation during critical bleeding.

Cardiovascular Disease in Patients with End-Stage Renal Disease on Hemodialysis

Cardiovascular disease is a major concern for patients with end-stage renal disease (ESRD), especially those on hemodialysis. ESRD patients with coronary artery disease often do not have symptoms or present with atypical symptoms. Coronary lesions in ESRD patients are characterized by increased media thickness, infiltration and activation of macrophages, and marked calcification. Several studies showed worsened clinical outcomes after coronary revascularization, which were dependent on the severity of renal dysfunction. ESRD patients on hemodialysis have the most severe renal dysfunction; thus, the clinical outcomes are worse in these patients than in those with other types of renal dysfunction. Medications for primary or secondary cardiovascular prevention are also insufficient in ESRD patients. Efficacy of drug-eluting stents is inferior in ESRD patients, compared to the excellent outcomes observed in patients with normal renal function. Unsatisfactory outcomes with trials targeting cardiovascular disease in patients with ESRD emphasize a large potential to improve outcomes. Thus, optimal strategies for diagnosis, prevention, and management of cardiovascular disease should be modified in ESRD patients.

Acute Coronary Syndromes: Unstable Angina and Non-ST Elevation Myocardial Infarction

Non-ST elevation acute coronary syndromes (NSTE-ACS) encompass the clinical entities of unstable angina and non-ST elevation myocardial infarction. Several advances have occurred over the past decade, including the emergence of new antiplatelet and antithrombotic therapies and novel treatment strategies, leading to marked improvements in mortality. However, there has also been an increased incidence in NSTE-ACS as a result of the use of high-sensitivity troponins and the increase in cardiovascular risk factors. This article provides a focused update on contemporary management strategies pertaining to antiplatelet, antithrombotic, and anti-ischemic therapies and to revascularization strategies in patients with ACS.

[Anti-platelets without a bleeding risk: novel targets and strategies]

Anti-platelet agents such as aspirin, clopidogrel and antagonists of integrin αIIbβ3 allowed to efficiently reduce morbidity and mortality associated with arterial thrombosis. A major limit of these drugs is that they increase the risk of bleeding. During the last few years, several innovative anti-thrombotic strategies with a potentially low bleeding risk were proposed. These approaches target the collagen receptor glycoprotein (GP) VI, the GPIb/von Willebrand factor axis, the thrombin receptor PAR-1, the activated form of integrin αIIbβ3 or the ADP receptor P2Y1. While an antagonist of PAR-1 was recently marketed, the clinical proofs of the efficiency and safety of the other agents remain to be established. This review evaluates these new anti-platelet approaches toward safer anti-thrombotic therapies.

Clinical pharmacokinetics and pharmacodynamics of clopidogrel

Acute coronary syndromes (ACS) remain life-threatening disorders, which are associated with high morbidity and mortality. Dual antiplatelet therapy with aspirin and clopidogrel has been shown to reduce cardiovascular events in patients with ACS. However, there is substantial inter-individual variability in the response to clopidogrel treatment, in addition to prolonged recovery of platelet reactivity as a result of irreversible binding to P2Y12 receptors. This high inter-individual variability in treatment response has primarily been associated with genetic polymorphisms in the genes encoding for cytochrome (CYP) 2C19, which affect the pharmacokinetics of clopidogrel. While the US Food and Drug Administration has issued a boxed warning for CYP2C19 poor metabolizers because of potentially reduced efficacy in these patients, results from multivariate analyses suggest that additional factors, including age, sex, obesity, concurrent diseases and drug-drug interactions, may all contribute to the overall between-subject variability in treatment response. However, the extent to which each of these factors contributes to the overall variability, and how they are interrelated, is currently unclear. The objective of this review article is to provide a comprehensive update on the different factors that influence the pharmacokinetics and pharmacodynamics of clopidogrel and how they mechanistically contribute to inter-individual differences in the response to clopidogrel treatment.

The Aryl Hydrocarbon Receptor is a Critical Regulator of Tissue Factor Stability and an Antithrombotic Target in Uremia

Patients with CKD suffer high rates of thrombosis, particularly after endovascular interventions, yet few options are available to improve management and reduce thrombotic risk. We recently demonstrated that indoxyl sulfate (IS) is a potent CKD-specific prothrombotic metabolite that induces tissue factor (TF) in vascular smooth muscle cells (vSMCs), although the precise mechanism and treatment implications remain unclear. Because IS is an agonist of the aryl hydrocarbon receptor (AHR), we first examined the relationship between IS levels and AHR-inducing activity in sera of patients with ESRD. IS levels correlated significantly with both vSMC AHR activity and TF activity. Mechanistically, we demonstrated that IS activates the AHR pathway in primary human aortic vSMCs, and further, that AHR interacts directly with and stabilizes functional TF. Antagonists directly targeting AHR enhanced TF ubiquitination and degradation and suppressed thrombosis in a postinterventional model of CKD and endovascular injury. Furthermore, AHR antagonists inhibited TF in a manner dependent on circulating IS levels. In conclusion, we demonstrated that IS regulates TF stability through AHR signaling and uncovered AHR as an antithrombotic target and AHR antagonists as a novel class of antithrombotics. Together, IS and AHR have potential as uremia-specific biomarkers and targets that may be leveraged as a promising theranostic platform to better manage the elevated thrombosis rates in patients with CKD.

High clopidogrel dose in patients with chronic kidney disease having clopidogrel resistance after percutaneous coronary intervention

We evaluated the impact of clopidogrel 150 mg/d in patients with chronic kidney disease (CKD) having clopidogrel resistance (CR) after percutaneous coronary intervention (PCI); 1076 consecutive patients with coronary artery disease (CAD) having CKD were enrolled. Maximal platelet aggregation (MPA) was assessed before, 24 hours, and 30 days after a 300-mg loading dose of clopidogrel prior to PCI. After PCI, 370 patients with CR were randomized to receive clopidogrel 75 mg/d (n = 184) or 150 mg/d (n = 186) for 30 days. Stent thrombosis (ST), major adverse cardiac events (MACEs), and bleeding were analyzed after 1 month. Patients in the 150 mg group had significant lower rates of ST and MACE. There was no significant difference in major or minor bleeding. Patients in the 150 mg group had lower MPA and greater inhibition of platelet aggregation. One-month administration of 150 mg/d of clopidogrel decreases the rate of ST and MACE without increasing bleeding in patients with CKD having CR after PCI.

Effectiveness and Safety of Antiplatelet in Stroke Patients with End-Stage Renal Disease Undergoing Dialysis

Background

Antiplatelet therapy is known to decrease the risk of secondary ischemic stroke. However, the effectiveness and safety of antiplatelet therapy in patients with end-stage renal disease are uncertain, especially in dialysis.

Aims and/or hypothesis

We estimated the effectiveness and safety of antiplatelet drugs (aspirin and clopidogrel) for the prevention of recurrent ischemic stroke in end-stage renal disease patients undergoing dialysis during long-term follow-up after first-time ischemic stroke.

Methods

The cases were identified from the National Health Insurance Research Database. Antiplatelet therapy was administered for 11 years to patients experiencing a first ischemic stroke between 1998 and 2006. Primary outcomes, including death and readmission to hospital for stroke, and secondary outcomes, including death, stroke, and acute myocardial infarction or bleeding, were examined.

Results

In total, 1936 patients experienced a first ischemic stroke during the follow-up. In a time-dependent analysis, the hazard ratio for primary outcomes in patients treated with aspirin was 0·671 ( P < 0·001) and that for clopidogrel was 0·933 ( P = 0·497). At secondary outcomes, patients treated with aspirin, hazard ratio for readmission for stroke was 0·715 ( P = 0·002) and that for bleeding was 0·885 ( P = 0·291). Independent risk factors for mortality and readmission due to ischemic stroke included age, diabetes mellitus, and administration of proton pump inhibitors.

Conclusions

Antiplatelet therapy, especially aspirin, still offers safe and effective treatment for ischemic stroke prevention in patients with end-stage renal disease undergoing dialysis.

Treatment of non-ST-elevation myocardial infarction and ST-elevation myocardial infarction in patients with chronic kidney disease

Renal dysfunction is frequent in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Chronic kidney disease (CKD) is associated with very poor prognosis and is an independent predictor of early and late mortality and major bleeding in patients with NSTE-ACS. Patients with NSTE-ACS and CKD are still rarely treated according to guidelines. Medical registers reveal that patients with CKD are usually treated with too high doses of antithrombotics, especially anticoagulants and inhibitors of platelet glycoprotein (GP) IIb/IIIa receptors, and therefore they are more prone to bleeding. Drugs which are excreted mainly or exclusively by the kidney should be administered in a reduced dose or discontinued in patients with CKD. These drugs include enoxaparin, fondaparinux, bivalirudin, and small molecule inhibitors of GP IIb/IIIa inhibitors. In long-term treatment of patients after myocardial infarction, anti-platelet therapy, lipid-lowering therapy and β-blockers are used. Chronic kidney disease patients before qualification for coronary interventions should be carefully selected in order to avoid their use in the group of patients who could not benefit from such procedures. This paper presents schemes of non-ST and ST-segment elevation myocardial infarction treatment in CKD patients in accordance with the current recommendations of the European Society of Cardiology (ESC).

Japanese postmarketing surveillance of clopidogrel for patients with non-ST-segment-elevation acute coronary syndrome indicated for percutaneous coronary intervention (J-PLACE NSTE-ACS)

Clopidogrel in combination with aspirin has been a standard therapy for patients who have undergone percutaneous coronary intervention. The present study was conducted as a postmarketing surveillance, for the purpose of assessing the safety and efficacy of clopidogrel in real clinical practice in patients with non-ST-segment-elevation acute coronary syndrome (NSTE-ACS). Subjects were registered between March 2008 and December 2010, and as a result, patients not only with NSTE-ACS but also other types of ischemic heart diseases were enrolled. Data on off-label subjects were used only in safety evaluation. After excluding patients with inappropriate clinical report forms, 3,673 patients with non-ST-segment-elevation myocardial infarction, unstable angina, STEMI, stable angina, or old myocardial infarction were observed for safety evaluation. Efficacy was assessed in 2,562 of the 3,673 patients with NSTE-ACS. Aspirin was concomitantly prescribed to 3,615/3,673 (98.6 %) of the safety group, and 2,374/3,673 (64.6 %) received a loading dose of clopidogrel. During a maximum follow-up period of 12 months, 397 (10.8 %) of the 3,673 patients experienced adverse drug reactions (ADRs), of whom 145 (4.0 %) had serious conditions, as classified by the investigators. The most frequently observed ADRs were hepatobiliary and gastrointestinal disorders. Bleeding adverse events were observed in 138 patients (3.8 %) and 80 cases (2.2 %) were considered as serious. The 1-year cumulative incidence of major adverse cardiovascular events and major adverse cardiac and cerebrovascular events in the patients with NSTE-ACS were estimated to be 11.6 and 12.2 %, respectively. Serious AEs that substantially affect the safety profile of clopidogrel were not confirmed.

Impact of Worsening Renal Dysfunction on the Comparative Efficacy of Bivalirudin and Platelet Glycoprotein IIb/IIIa Inhibitors

Background—

Use of bivalirudin has been associated with a reduction in the incidence of bleeding in patients undergoing percutaneous coronary intervention. Patients with chronic kidney disease, a known predictor of post–percutaneous coronary intervention bleeding, are under-represented in clinical trials.

Methods and Results—

We evaluated the outcome of 64 052 patients who underwent percutaneous coronary intervention from 2007 to 2009 at 33 hospitals in Michigan and were treated with bivalirudin (28 378) or with heparin and glycoprotein IIb/IIIa inhibitors (35 674). Propensity-matched analysis was adjusted for the nonrandomized use of the 2 strategies. Patients treated with bivalirudin were older, had a lower glomerular filtration rate, and had more comorbidities. Use of bivalirudin was associated with fewer transfusions (2.8% versus 4.2%; P <0.0001), gastrointestinal bleeds (0.5% versus 1.3%; P <0.0001), and vascular complications (1.0% versus 2.5%; P <0.0001), with no difference in survival. Bleeding complications were more common with worsening renal function, but use of bivalirudin was associated with less bleeding across the continuum of renal dysfunction.

Conclusions—

The risk of bleeding after percutaneous coronary intervention increases with worsening chronic kidney disease. Bivalirudin was associated with a dramatically reduced risk of bleeding across all categories of renal dysfunction. Our study findings suggest that bivalirudin monotherapy is an acceptable, if not the more appropriate alternative, to heparin and glycoprotein IIb/IIIa inhibitors in patients with chronic kidney disease.

Antiplatelet therapy in the management of cardiovascular disease in patients with CKD: what is the evidence?

Antiplatelet agents (APAs) are proven to reduce risk of major cardiovascular events in patients with cardiovascular disease and normal kidney function. With recent post hoc analyses of large trials questioning the safety and efficacy of APAs in CKD, major gaps exist in our understanding of platelet aggregability and the effects of APAs on thrombosis and bleeding in CKD. Clinical practice guidelines are ambiguous about use of such agents in CKD patients, because patients with moderate to advanced CKD were systematically excluded from clinical trials of APAs. CKD patients experience excessive rates of cardiovascular thrombotic events, yet paradoxically are at higher risk for major bleeding while receiving APAs. Furthermore, observational studies suggest that CKD patients may exhibit poor response to APAs. High residual platelet aggregability, as determined by inhibition of platelet aggregation, is associated with increased risk for cardiovascular events. In addition, metabolism of certain APAs may be altered in CKD patients. It is, therefore, imperative to explore the mechanisms responsible for poor response to APAs in CKD patients in order to use these drugs more safely and effectively. This review identifies the knowledge gaps and future trials needed to address those issues with the use of APAs in CKD patients.