Outcomes in patients treated with ticagrelor versus clopidogrel after acute myocardial infarction stratified by renal function

OBJECTIVES

We aimed to analyse outcomes of ticagrelor and clopidogrel stratified by estimated glomerular filtration rate (eGFR) in a large unselected cohort of patients with acute myocardial infarction (MI).

METHODS

We used follow-up data in MI survivors discharged on ticagrelor or clopidogrel enrolled in the Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies registry. The association between ticagrelor versus clopidogrel and the primary composite outcome of death, MI or stroke and the secondary outcome rehospitalisation with bleeding diagnosis at 1 year, was studied using adjusted Cox proportional hazards models, stratifying after eGFR levels.

RESULTS

In total, 45 206 patients with MI discharged on clopidogrel (n=33 472) or ticagrelor (n=11 734) were included. The unadjusted 1-year event rate for the composite endpoint of death, MI or stroke was 7.0%, 18.0% and 48.0% for ticagrelor treatment and 11.0%, 33.0% and 64.0% for clopidogrel treatment in patients with eGFR_>60 (n=33 668), eGFR_30-60 (n=9803) and eGFR_<30 (n=1735), respectively. After adjustment, ticagrelor as compared with clopidogrel was associated with a lower 1-year risk of the composite outcome (eGFR_>60: HR 0.87, 95% CI 0.76 to 99, eGFR_30-60: 0.82 (0.70 to 0.97), eGFR_<30: 0.95 (0.69 to 1.29), P for interaction=0.55) and a higher risk of bleeding (eGFR_>60: HR 1.10, 95% CI 0.90 to 1.35, eGFR_30-60: 1.13 (0.84 to 1.51), eGFR_<30: 1.79 (1.00 to 3.21), P for interaction=0.30) across the eGFR strata.

CONCLUSIONS

Treatment with ticagrelor as compared with clopidogrel in patients with MI was associated with lower risk for the composite of death, MI or stroke and a higher bleeding risk across all strata of eGFR. Of caution, bleeding events were more abundant in patients with eGFR_<30.

High-density lipoprotein from end-stage renal disease patients exhibits superior cardioprotection and increase in sphingosine-1-phosphate

BACKGROUND

Chronic kidney disease (CKD) exacerbates the risk of death due to cardiovascular disease (CVD). Modifications to blood lipid metabolism which manifest as increases in circulating triglycerides and reductions in high-density lipoprotein (HDL) cholesterol are thought to contribute to increased risk. In CKD patients, higher HDL cholesterol levels were not associated with reduced mortality risk. Recent research has revealed numerous mechanisms by which HDL could favourably influence CVD risk. In this study, we compared plasma levels of sphingosine-1-phosphate (S1P), HDL-associated S1P (HDL-S1P) and HDL-mediated protection against oxidative stress between CKD and control patients.

METHODS

High-density lipoprotein was individually isolated from 20 CKD patients and 20 controls. Plasma S1P, apolipoprotein M (apoM) concentrations, HDL-S1P content and the capacity of HDL to protect cardiomyocytes against doxorubicin-induced oxidative stress in vitro were measured.

RESULTS

Chronic kidney disease patients showed a typical profile with significant reductions in plasma HDL cholesterol and albumin and an increase in triglycerides and pro-inflammatory cytokines (TNF-alpha and IL-6). Unexpectedly, HDL-S1P content (P = .001) and HDL cardioprotective capacity (P = .034) were increased significantly in CKD patients. Linear regression analysis of which factors could influence HDL-S1P content showed an independent, negative and positive association with plasma albumin and apoM levels, respectively.

DISCUSSION

The novel and unexpected observation in this study is that uremic HDL is more effective than control HDL for protecting cardiomyocytes against oxidative stress. It is explained by its higher S1P content which we previously demonstrated to be the determinant of HDL-mediated cardioprotective capacity. Interestingly, lower concentrations of albumin in CKD are associated with higher HDL-S1P.

Pharmacogenomic Impact of CYP2C19 Variation on Clopidogrel Therapy in Precision Cardiovascular Medicine

Variability in response to antiplatelet therapy can be explained in part by pharmacogenomics, particularly of the CYP450 enzyme encoded by CYP2C19. Loss-of-function and gain-of-function variants help explain these interindividual differences. Individuals may carry multiple variants, with linkage disequilibrium noted among some alleles. In the current pharmacogenomics era, genomic variation in CYP2C19 has led to the definition of pharmacokinetic phenotypes for response to antiplatelet therapy, in particular, clopidogrel. Individuals may be classified as poor, intermediate, extensive, or ultrarapid metabolizers, based on whether they carry wild type or polymorphic CYP2C19 alleles. Variant alleles differentially impact platelet reactivity, concentration of plasma clopidogrel metabolites, and clinical outcomes. Interestingly, response to clopidogrel appears to be modulated by additional factors, such as sociodemographic characteristics, risk factors for ischemic heart disease, and drug-drug interactions. Furthermore, systems medicine studies suggest that a broader approach may be required to adequately assess, predict, preempt, and manage variation in antiplatelet response. Transcriptomics, epigenomics, exposomics, miRNAomics, proteomics, metabolomics, microbiomics, and mathematical, computational, and molecular modeling should be integrated with pharmacogenomics for enhanced prediction and individualized care. In this review of pharmacogenomic variation of CYP450, a systems medicine approach is described for tailoring antiplatelet therapy in clinical practice of precision cardiovascular medicine.

Identification of novel molecular signatures of IgA nephropathy through an integrative -omics analysis

IgA nephropathy (IgAN) is the most prevalent among primary glomerular diseases worldwide. Although our understanding of IgAN has advanced significantly, its underlying biology and potential drug targets are still unexplored. We investigated a combinatorial approach for the analysis of IgAN-relevant -omics data, aiming at identification of novel molecular signatures of the disease. Nine published urinary proteomics datasets were collected and the reported differentially expressed proteins in IgAN vs. healthy controls were integrated into known biological pathways. Proteins participating in these pathways were subjected to multi-step assessment, including investigation of IgAN transcriptomics datasets (Nephroseq database), their reported protein-protein interactions (STRING database), kidney tissue expression (Human Protein Atlas) and literature mining. Through this process, from an initial dataset of 232 proteins significantly associated with IgAN, 20 pathways were predicted, yielding 657 proteins for further analysis. Step-wise evaluation highlighted 20 proteins of possibly high relevance to IgAN and/or kidney disease. Experimental validation of 3 predicted relevant proteins, adenylyl cyclase-associated protein 1 (CAP1), SHC-transforming protein 1 (SHC1) and prolylcarboxypeptidase (PRCP) was performed by immunostaining of human kidney sections. Collectively, this study presents an integrative procedure for -omics data exploitation, giving rise to biologically relevant results.

Associations Between Chronic Kidney Disease and Outcomes With Use of Prasugrel Versus Clopidogrel in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention: A Report From the PROMETHEUS Study

OBJECTIVES

This study sought to compare clinical outcomes in a contemporary acute coronary syndrome (ACS) percutaneous coronary intervention (PCI) cohort stratified by chronic kidney disease (CKD) status.

BACKGROUND

Patients with CKD exhibit high risks for both thrombotic and bleeding events, thus complicating decision making regarding antiplatelet therapy in the setting of ACS.

METHODS

The PROMETHEUS study was a multicenter observational study comparing outcomes with prasugrel versus clopidogrel in ACS PCI patients. Major adverse cardiac events (MACE) at 90 days and at 1 year were defined as a composite of death, myocardial infarction, stroke, or unplanned revascularization. Clinically significant bleeding was defined as bleeding requiring transfusion or hospitalization. Cox regression multivariable analysis was performed for adjusted associations between CKD status and clinical outcomes. Hazard ratios for prasugrel versus clopidogrel treatment were generated using propensity score stratification.

RESULTS

The total cohort included 19,832 patients, 28.3% with and 71.7% without CKD. CKD patients were older with greater comorbidities including diabetes and multivessel disease. Prasugrel was less often prescribed to CKD versus non-CKD patients (11.0% vs. 24.0%, respectively; p < 0.001). At 1 year, CKD was associated with higher adjusted risk of MACE (1.27; 95% confidence interval: 1.18 to 1.37) and bleeding (1.46; 95% confidence interval: 1.24 to 1.73). Although unadjusted rates of 1-year MACE were lower with prasugrel versus clopidogrel in both CKD (18.3% vs. 26.5%; p < 0.001) and non-CKD (10.9% vs. 17.9%; p < 0.001) patients, associations were attenuated after propensity stratification. Similarly, unadjusted differences in 1-year bleeding with prasugrel versus clopidogrel (6.0% vs. 7.4%; p = 0.18 in CKD patients; 2.6% vs. 3.5%; p = 0.008 in non-CKD patients) were not significant after propensity score adjustment.

CONCLUSIONS

Although risks for 1-year MACE were significantly higher in ACS PCI patients with versus without CKD, prasugrel use was 50% lower in patients with renal impairment. Irrespective of CKD status, outcomes associated with prasugrel use were not significant after propensity adjustment. These data highlight the need for randomized studies evaluating the optimal antiplatelet therapy in CKD patients with ACS.

Platelet reactivity in stable cardiovascular patients with chronic kidney disease

The study aimed to evaluate antiplatelet drug responsiveness in stable outpatients with cardiovascular disease and chronic kidney disease (CKD) and examine whether impaired antiplatelet drug responsiveness is associated with worse clinical outcomes in this population. Stable cardiovascular patients (n = 771) were enrolled at least one month after an acute ischemic atherothrombotic event. Antiplatelet drug responsiveness was assessed with specific assays (serum TxA₂ for aspirin, the VASP assay for clopidogrel) and other aggregation-based assays using different agonists. All patients were followed until the first occurrence of a major adverse cardiovascular event. The 133 CKD patients were found to have higher activity of von Willebrand factor and higher fibrinogen levels. After a median follow-up of 33 months, 88 events occurred in patients without CKD and 31 events in patients with CKD (5.0 events and 8.7 events per 100 patient years, respectively, HR = 1.75 (95% CI 1.16-2.63; p = 0.008). The prevalence of poor aspirin and clopidogrel responsiveness and high platelet reactivity as assessed with different aggregation-based assays was similar in patients with estimated GFR ≥ 60 ml/min, 45-59 ml/min, and < 45 ml/min. No significant interaction for CKD vs. non-CKD was observed for events occurrence in patients with or without high platelet reactivity on several assays, with the exception of collagen-induced aggregation. In stable cardiovascular patients, CKD is not associated with higher platelet reactivity. Decreased antiplatelet drug responsiveness is not associated with worse clinical outcomes in CKD patients.

Disaggregation Following Agonist-Induced Platelet Activation in Patients on Dual Antiplatelet Therapy

Disaggregation as the difference between maximal and final platelet aggregation by light transmission aggregometry indicates the stability of platelet aggregates. We evaluated the extent of disaggregation after platelet stimulation with adenosine diphosphate (ADP), arachidonic acid (AA), collagen, epinephrine, and thrombin receptor-activating peptide (TRAP)-6 in 323 patients on dual antiplatelet therapy with daily aspirin and clopidogrel (group 1), prasugrel (group 2), or ticagrelor (group 3) therapy. All patients in group 1 underwent elective angioplasty and stenting, whereas all patients included in groups 2 and 3 suffered from acute coronary syndromes (STEMI or NSTEMI) and underwent urgent PCI. Significant differences between maximal and final platelet aggregation were observed with all agonists throughout the groups (all p<0.001). Disaggregation was highest using AA (clopidogrel 36.5%; prasugrel/ticagrelor 100%) and ADP (clopidogrel 21.7%; prasugrel/ticagrelor 100%). In contrast, low disaggregation was observed after platelet stimulation with collagen and TRAP-6 in clopidogrel-treated patients, and after platelet stimulation with collagen and epinephrine in prasugrel- and ticagrelor-treated patients. In conclusion, pathways of platelet activation that are not inhibited by standard antiplatelet therapy allow persisting platelet aggregation and may at least in part be responsible for adverse ischemic events.

Different impact of aspirin on renal progression in patients with predialysis advanced chronic kidney disease with or without previous stroke

BACKGROUND

The benefit of reducing the risk of stroke against increasing the risk of renal progression associated with antiplatelet therapy in patients with advanced chronic kidney disease (CKD) is controversial.

METHODS

We enrolled 1301 adult patients with advanced CKD treated with erythropoiesis stimulating agents from January 1, 2002 to June 30, 2009 from the 2005 Longitudinal Health Insurance Database in Taiwan. All of the patients were followed until the development of the primary or secondary endpoints, or the end of the study (December 31, 2011). The primary endpoint was the development of ischemic stroke, and the secondary endpoints included hospitalization for bleeding events, cardiovascular mortality, all-cause mortality, and renal failure. The adjusted cumulative probability of events was calculated using multivariate Cox proportional regression analysis.

RESULTS

Adjusted survival curves showed that the usage of aspirin was not associated with ischemic stroke, hospitalization for bleeding events, cardiovascular mortality or all-cause mortality, however, it was significantly associated with renal failure. In subgroup analysis, aspirin use was associated with renal failure in the patients with no history of stroke (HR, 1.41; 95% CI, 1.14-1.73), and there was a borderline interaction between previous stroke and the use of aspirin on renal failure (interaction p=0.0565).

CONCLUSIONS

There was no significant benefit in preventing ischemic stroke in the patients with advanced CKD who received aspirin therapy. Furthermore, the use of aspirin was associated with the risk of renal failure in the patients with advanced CKD without previous stroke.

The Personalization of Clopidogrel Antiplatelet Therapy: The Role of Integrative Pharmacogenetics and Pharmacometabolomics

Dual antiplatelet therapy of aspirin and clopidogrel is pivotal for patients undergoing percutaneous coronary intervention. However, the variable platelets reactivity response to clopidogrel may lead to outcome failure and recurrence of cardiovascular events. Although many genetic and nongenetic factors are known, great portion of clopidogrel variable platelets reactivity remain unexplained which challenges the personalization of clopidogrel therapy. Current methods for clopidogrel personalization include CYP2C19 genotyping, pharmacokinetics, and platelets function testing. However, these methods lack precise prediction of clopidogrel outcome, often leading to insufficient prediction. Pharmacometabolomics which is an approach to identify novel biomarkers of drug response or toxicity in biofluids has been investigated to predict drug response. The advantage of pharmacometabolomics is that it does not only predict the response but also provide extensive information on the metabolic pathways implicated with the response. Integrating pharmacogenetics with pharmacometabolomics can give insight on unknown genetic and nongenetic factors associated with the response. This review aimed to review the literature on factors associated with the variable platelets reactivity response to clopidogrel, as well as appraising current methods for the personalization of clopidogrel therapy. We also aimed to review the literature on using pharmacometabolomics approach to predict drug response, as well as discussing the plausibility of using it to predict clopidogrel outcome.

Aspirate from human stented saphenous vein grafts induces epicardial coronary vasoconstriction and impairs perfusion and left ventricular function in rat bioassay hearts with pharmacologically induced endothelial dysfunction

Stent implantation into aortocoronary saphenous vein grafts (SVG) releases particulate debris and soluble vasoactive mediators, for example, serotonin. We now analyzed effects of the soluble mediators released into the coronary arterial blood during stent implantation on vasomotion of isolated rat epicardial coronary artery segments and on coronary flow and left ventricular developed pressure in isolated perfused rat hearts. Coronary blood was retrieved during percutaneous SVG intervention using a distal occlusion/aspiration protection device in nine symptomatic patients with stable angina pectoris and a flow‐limiting SVG stenosis. The blood was separated into particulate debris and plasma. Responses to coronary plasma were determined in isolated rat epicardial coronary arteries and in isolated, constant pressure‐perfused rat hearts (±nitric oxide synthase [NOS] inhibition and ±serotonin receptor blockade, respectively). Coronary aspirate plasma taken after stent implantation induced a stronger vasoconstriction of rat epicardial coronary arteries (52 ± 8% of maximal potassium chloride induced vasoconstriction [% KCl_max = 100%]) than plasma taken before stent implantation (12 ± 8% of KCl_max); NOS inhibition augmented this vasoconstrictor response (to 110 ± 15% and 24 ± 9% of KCl_max). Coronary aspirate plasma taken after stent implantation reduced in isolated perfused rat hearts only under NOS inhibition coronary flow by 17 ± 3% and left ventricular developed pressure by 25 ± 4%. Blockade of serotonin receptors abrogated these effects. Coronary aspirate plasma taken after stent implantation induces vasoconstriction in isolated rat epicardial coronary arteries and reduces coronary flow and left ventricular developed pressure in isolated perfused rat hearts with pharmacologically induced endothelial dysfunction.

Diagnosis and management of atherosclerotic cardiovascular disease in chronic kidney disease: a review

Patients with chronic kidney disease (CKD) have a high prevalence of atherosclerotic cardiovascular disease, likely reflecting the presence of traditional risk factors. A greater distinguishing feature of atherosclerotic cardiovascular disease in CKD is the severity of the disease, which is reflective of an increase in inflammatory mediators and vascular calcification secondary to hyperparathyroidism of renal origin that are unique to patients with CKD. Additional components of atherosclerotic cardiovascular disease that are prominent in patients with CKD include microvascular disease and myocardial fibrosis. Therapeutic interventions that minimize cardiovascular events related to atherosclerotic cardiovascular disease in patients with CKD, as determined by well-designed clinical trials, are limited to statins. Data are lacking regarding other available therapeutic measures primarily due to exclusion of patients with CKD from major trials studying cardiovascular disease. Data from well-designed randomized controlled trials are needed to guide clinicians who care for this high-risk population in the management of atherosclerotic cardiovascular disease to improve clinical outcomes.

Long-term versus short-term dual antiplatelet therapy was similarly associated with a lower risk of death, stroke, or infarction in patients with acute coronary syndrome regardless of underlying kidney disease

Scarce and conflicting evidence exists on whether clopidogrel is effective and whether dual antiplatelet treatment (DAPT) is safe in patients with acute coronary syndrome and chronic kidney disease (CKD). To study this, we performed an observational, prospective, multicenter cohort study of 36,001 patients of the SWEDEHEART registry. The exposure was DAPT prolonged after 3 months versus DAPT stopped at 3 months in consecutive patients with acute coronary syndrome and known serum creatinine. DAPT duration with clopidogrel and aspirin was assessed by dispensed tablets. CKD stages were classified according to estimated glomerular filtration rate (eGFR). Study outcomes were 1) the composite of death, myocardial infarction, or ischemic stroke; 2) bleeding; or 3) the aggregate of these two outcomes within day 111 and 365 from discharge. A longer DAPT duration, as compared with 3-month DAPT, was associated with lower hazard ratios for outcome one in each CKD stratum (eGFR over 60, adjusted hazard ratio [95% confidence interval] 0.76 [0.67-0.85]; eGFR 60 and less, 0.84 [0.73-0.96], of which eGFR between 45 and 60, 0.85 [0.70-1.05], eGFR between 30 and 45, 0.78 [0.62-0.97]; eGFR 30 and less ml/min/1.73 m², 0.93 [0.70-1.24]. Bleeding (outcome 2) was in general more common in the longer DAPT group of each aforementioned CKD stratum. Aggregated outcome analysis (outcome 3) similarly favored longer DAPT in each stratum. There was no interaction between DAPT duration and CKD strata for any of the study outcomes. Thus, a prolonged as compared with three-month DAPT was similarly associated with a lower risk of death, stroke, or reinfarction regardless of underlying CKD.

Effect of Estimated Glomerular Filtration Rate Decline on the Efficacy and Safety of Clopidogrel With Aspirin in Minor Stroke or Transient Ischemic Attack

Background and Purpose—

Patients with chronic kidney disease (CKD) are at a particularly high risk for ischemic and bleeding events. Limited data exist as to the efficacy and safety of clopidogrel in stroke patients with renal dysfunction. Therefore, we sought to assess the impact of decreased kidney function on clinical outcomes for stroke patients on clopidogrel–aspirin treatment.

Methods—

Patients in the CHANCE trial (Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events) were randomized to clopidogrel–aspirin or aspirin-alone treatment. The primary efficacy outcome was new stroke during 90 days, whereas bleeding was the safety outcome. Patients were stratified according to estimated glomerular filtration rate.

Results—

Dual clopidogrel–aspirin therapy was associated with a marked reduction in new strokes compared with the therapy of aspirin alone in patients with normal renal function (hazard ratio, 0.77; 95% confidence interval, 0.60–0.98; P =0.02) and mild CKD (hazard ratio, 0.60; 95% confidence interval, 0.45–0.79; P <0.01), whereas in patients with moderate CKD, no significant benefit from clopidogrel therapy was detected (hazard ratio, 1.00; 95% confidence interval, 0.43–2.35; P =0.99). There was no clear difference in bleeding episodes by treatment assignment across categories of renal impairment.

Conclusions—

Clopidogrel plus aspirin could decrease new stroke in patients with normal kidney function and mild CKD, but no extra benefit was observed in those with moderate CKD. Bleeding risk from the dual therapy did not seem to increase in mild or moderate CKD patients.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00979589.

Impact of chronic kidney disease on platelet inhibition of clopidogrel and prasugrel in Japanese patients

BACKGROUND

The impact of chronic kidney disease (CKD) on the antiplatelet effect of clopidogrel and low-dose (3.75mg) prasugrel in Japanese patients is largely unknown.

METHODS

A total of 53 consecutive Japanese patients with stable coronary artery disease who received aspirin and clopidogrel were enrolled, and categorized by estimated glomerular filtration rate (eGFR): CKD group (n=15, eGFR<60ml/min/1.73m²) and non-CKD group (n=38, eGFR≥60ml/min/1.73m²). Clopidogrel was switched to 3.75mg prasugrel. Platelet reactivity measurement using the VerifyNow P2Y12 assay (Accumetrics, San Diego, CA, USA) was performed at baseline (on clopidogrel) and day 14 (on prasugrel).

RESULTS

The VerifyNow P2Y12 reaction units (PRU) during clopidogrel therapy was significantly higher in the CKD group than that in the non-CKD group (185.2±51.1 PRU vs. 224.3±57.0 PRU, p=0.02), whereas, the PRU with the prasugrel therapy in the CKD group and non-CKD group were not significantly different (149.9±51.1 PRU vs. 165.3±61.8 PRU, p=0.36). The PRU was significantly lower with the prasugrel therapy compared to that with the clopidogrel therapy both in the CKD group and in the non-CKD group.

CONCLUSIONS

Antiplatelet effect of clopidogrel but not prasugrel is attenuated in patients with CKD. Prasugrel achieves a consistently lower platelet reactivity compared with clopidogrel regardless of the presence of mild to moderate CKD.

The Antiplatelet Effect of Clopidogrel Decreases With Patient Age

Recent data suggest that clopidogrel-mediated platelet inhibition is age dependent. However, so far the effect of age on adenosine diphosphate (ADP)-inducible platelet reactivity has only been investigated by test systems measuring surrogate markers of platelet aggregation. We therefore sought to study the impact of age on platelet inhibition by clopidogrel by whole-blood flow cytometry. Platelet surface P-selectin expression, activated glycoprotein (GP) IIb/IIIa, and monocyte-platelet aggregate (MPA) formation were determined by flow cytometry in 302 patients with dual antiplatelet therapy after successful angioplasty and stenting. Patient age was independently associated with ADP-inducible P-selectin expression, GPIIb/IIIa, and MPA formation (all P < .05). Moreover, platelet surface expressions of P-selectin and activated GPIIb/IIIa were significantly higher in patients ≥75 years compared with younger patients (both P ≤ .004). Likewise, MPA formation was significantly more pronounced in patients ≥75 years ( P = .02). Finally, high P-selectin and high GPIIb/IIIa were significantly more frequent in patients ≥75 years compared with younger patients (both P < .001). Further, high MPA ADP occurred more frequently in patients ≥75 years compared to younger patients ( P < .05). In conclusion, the antiplatelet effect of clopidogrel decreases with patient age.

The predictive value of different equations for estimation of glomerular filtration rate in patients with coronary artery disease - Results from the AtheroGene study

BACKGROUND

Impaired renal function leads to dramatically increased risk for the development and progression of coronary artery disease (CAD). Therefore we aimed to assess the predictive value of different equations for estimated glomerular filtration rate (eGFR) in CAD-patients.

METHODS

From the AtheroGene study 2135 patients were included. eGFR was calculated using the 4-variable Modification of Diet in Renal Disease (4MDRD) equation for serum creatinine (sCr), the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation for sCr and cystatin C (CysC) each alone, and in combination (CysC/sCr). eGFR was assessed regarding the combined outcome of cardiovascular death and non-fatal myocardial infarction and regarding complex CAD represented by a SYNTAX score ≥23. Median follow-up was 4.3years.

RESULTS

Only the CKD-EPI equation using CysC could differentiate between eGFR >90ml/min/1.73m(2) vs. eGFR 60-90ml/min/1.73m(2) according to the occurrence of an endpoint event (log-rank test p=0.009). In the Cox regression analysis only eGFR calculated by CKD-EPI equation for CysC (Hazard ratio per 1 standard deviation (HR) 1.27 (95% CI 1.07-1.50); p=0.007) and for CysC/sCr (HR 1.22 (95% CI 1.02-1.46); p=0.026) were predictive regarding the outcome after adjustment for cardiovascular risk factors and Nt-proBNP. Furthermore, only eGFR calculated by CKD-EPI equation for CysC (odds ratio (OR) 1.57 (95% CI 1.36-1.78); p<0.001) and for CysC/sCr (OR 1.32 (95% CI 1.13-1.53); p<0.001) were significantly associated with a SYNTAX score ≥23.

CONCLUSION

In patients with CAD the CKD-EPI equation for CysC and for CysC/sCr provided the best predictive value regarding the prognosis and the severity of CAD.

Calcium-Channel Blockers Attenuate the Antiplatelet Effect of Clopidogrel

AIMS

Dihydropyridine calcium-channel blockers (CCBs) inhibit cytochrome 3A4 and could therefore interfere with the conversion of clopidogrel to its active form. The impact of CCBs on the antiplatelet effect of clopidogrel has not been studied with assays directly capturing platelet activation to adenosine diphosphate (ADP), so far. We therefore sought to investigate platelet activation in response to ADP by flow cytometry in clopidogrel-treated patients without and with CCBs.

METHODS

Platelet surface P-selectin expression and activated glycoprotein (GP) IIb/IIIa in response to ADP were determined by flow cytometry in 302 patients on dual antiplatelet therapy with aspirin and clopidogrel after successful angioplasty with stent implantation.

RESULTS

Ninety-two patients (30.5%) received CCBs. Patients with concomitant CCB therapy showed significantly higher platelet surface expressions of P-selectin and activated GPIIb/IIIa in response to ADP than patients without CCBs (both P ≤ 0.03). Moreover, the fold increase of P-selectin and activated GPIIb/IIIa in response to ADP was significantly more pronounced in patients taking CCBs (both P ≤ 0.03). The associations of ADP-inducible activated GPIIb/IIIa and fold increase of activated GPIIb/IIIa after the addition of ADP with CCB therapy remained significant after adjustment for differences in patient characteristics and factors that were previously associated with clopidogrel response by multivariate regression analyses (both P < 0.05). High levels of ADP-inducible P-selectin and activated GPIIb/IIIa were seen significantly more frequent in patients with CCBs than in patients without CCB therapy (both P ≤ 0.01).

CONCLUSION

Dihydropyridine CCBs attenuate the effect of clopidogrel on ADP-inducible platelet activation in patients undergoing angioplasty and stenting for cardiovascular disease.

Uric acid and high-residual platelet reactivity in patients treated with clopidogrel or ticagrelor

BACKGROUND AND AIM

High residual platelet reactivity (HRPR) is still an important challenge, despite the advent of new potent ADP-antagonists. Therefore it is of extreme importance to identify factors that can influence platelet activation. Serum uric acid (SUA) has been largely addressed in the past as a possible risk factor for coronary artery disease, with a possible association with platelets hyperreactivity. So far no studies have assessed the role of serum uric acid on the response to dual antiplatelet therapy. Therefore, the aim of our study was to evaluate the impact of uric acid levels on platelet function in patients treated with dual antiplatelet therapy (DAPT) with clopidogrel or ticagrelor.

METHODS AND RESULTS

We scheduled for platelet function assessment at 30-90 days post-discharge patients treated with DAPT (ASA + clopidogrel or ticagrelor) for an ACS or elective percutaneous coronary intervention (PCI). Platelet function was assessed by whole blood impedance aggregometry (Multiplate(®)-Roche Diagnostics AG), HRPR was considered for ASPI test >862 AU(∗)min (for ASA) and ADP test values ≥417 AU* min (for ADP-antagonists).

RESULTS

We included a total of 493 patients (262 were on ASA and clopidogrel and 231 on ASA and ticagrelor). Patients were divided according to quartiles of serum uric acid levels measured at the time of platelet aggregation assessment (Group 1 <4.6 mg/dL, n = 114; Group 2, 4.7-5.8 mg/dL, n = 133; Group 3, 5.9-6.8 mg/dL, n = 124; Group 4, >6.9, n = 122). Patients with higher uric acid levels were older, more often smokers, with history of hypertension and previous coronary artery bypass surgery and renal failure and were more often on therapy with diuretics at admission. Patients with higher SUA had higher triglycerides and fibrinogen. Uric acid levels did not influence ASPI, COL, TRAP and ADP tests. High residual platelet reactivity (HRPR) was observed in 1.5% of patients treated with ASA, with no difference according to SUA quartiles (p = 0.60), confirmed at multivariate analysis after correction for baseline confounders (adjusted OR[95%CI] = 1.05 [0.44-2.52], p = 0.90). HRPR for ADP-antagonists was observed in 23.6% of patients, with no difference according to SUA quartiles (p = 0.47); this result was confirmed also after correction for baseline confounders (adjusted OR[95%CI] = 1.04 [0.84-1.28], p = 0.73). Moreover, no association was found between HRPR and uric acid levels both among patients treated with clopidogrel (p = 0.35) or ticagrelor (p = 0.74), that was confirmed after correction for baseline confounding factors (adjusted OR[95%CI] = 1.18 [0.90-1.55], p = 0.23) and (adjusted OR[95%CI] = 0.96 [0.63-1.47], p = 0.85). The absence of association between SUA and platelet reactivity was confirmed at linear regression analysis both with clopidogrel (r = 0.03, p = 0.55) or ticagrelor (r = -0.01, p = 0.85).

CONCLUSION

This is the first large study showing that in patients receiving DAPT, uric acid levels do not influence response to ticagrelor and clopidogrel or the effectiveness of ASA.

Impact of renal function on mean platelet volume and its relationship with coronary artery disease: A single-centre cohort study

BACKGROUND

Mean platelet volume (MPV) has been proposed as a marker of platelet reactivity and cardiovascular disease. Chronic kidney disease (CKD) significantly favors the occurrence of cardiovascular events, by increasing the circulating levels of a wide spectrum of pro-oxidant and pro-thrombotic mediators. However, opposite alterations of platelet function, both enhanced aggregability and increased bleeding diathesis have been reported in these patients, with contrasting results on the effects of renal function on MPV and coronary artery disease, that were assessed in present study.

METHODS

In patients undergoing coronary angiography, MPV and renal function (serum creatinine and estimated Glomerular Filtration Rate, eGFR, by MDRD formula) were assessed at admission. Coronary artery disease (CAD) was defined as a stenosis >50% in at least 1 coronary vessel, while severe CAD as left main or trivessel disease.

RESULTS

Among 3712 patients, 1044 (28.1%) had chronic kidney disease. CKD was related with age, female gender, diabetes and glycemic control, history of myocardial infarction, cerebrovascular accidents, coronary artery bypass grafting and left ventricular dysfunction or arrhythmias as indication to angiography, therapy with angiotensin-receptor blockers, nitrates, diuretics and calcium-antagonists, but lower rate of smoking, lower fibrinogen levels, haemoglobin, total and HDL cholesterol (p<0.001, respectively). CKD patients displayed increased severity and complexity of CAD (p<0.001) and significantly larger platelet volume (p<0.001), with CKD resulting as independent predictor of MPV above the median (≥10.85fl; Adjusted OR[95%CI]=1.56[1.23,1.99], p=0.002). Moreover, in the 1044 patients with renal failure, higher platelet volume (above the median value; ≥10.85fl) was associated with age (p=0.05), haemoglobin levels and platelet count (p<0.001), but not to a higher prevalence or extent of coronary artery disease (CAD: adjusted OR[95%CI]=0.80[0.58-1.09], p=0.16; severe CAD, adjusted OR[95%CI]=1.07[0.81-1.41], p=0.65).

CONCLUSIONS

Higher values of MPV are observed among patients with chronic kidney disease, inversely relating to eGFR. However, larger platelet size does not contribute to explain the increased severity of coronary artery disease observed among these patients.

Low-dose aspirin for prevention of cardiovascular disease in patients on hemodialysis: A 5-y prospective cohort study

Introduction Aspirin is an effective antiplatelet drug for preventing cardiovascular events in high-risk subjects. However, for patients with chronic kidney disease and undergoing hemodialysis (HD), its preventive efficacy remains controversial. The present study aimed to determine whether aspirin therapy reduces the risk of cardiovascular disease (CVD) and all-cause mortality in patients on HD. Methods We conducted a 5-y prospective cohort study involving patients on HD. Major exposure variables included prescription of aspirin (100 mg/d) and no aspirin (nonaspirin). The primary outcomes included all-cause death, cardiovascular events, hemorrhage, and ischemic stroke. The secondary outcome included bleeding events defined by the requirement of hospitalization. Findings In this study, 406 patients on regular HD were involved during a 5-y follow-up. Among these, 152 and 254 propensity-matched patients were enrolled in the aspirin and nonaspirin cohort, respectively. The cumulative survival rate was not significantly higher in the aspirin than in the nonaspirin users (log rank χ²  = 1.080, P = 0.299). Aspirin use was not significantly associated with reduced all-cause mortality, fatal and nonfatal congestive heart failure, as well as acute myocardial infarction and ischemic stroke. The risk of fatal cerebral hemorrhage was not significantly increased in the aspirin users (HR = 1.795, 95% CI 0.666-4.841, P = 0.174). After adjustment for other confounders, aspirin use was also not associated with decreased risk of all-cause mortality and CVD. Discussion The present prospective cohort study suggests that low-dose aspirin use is not associated with a significant decrease in the risks of all-cause mortality, CVD, and stroke in population undergoing HD (ClinicalTrials.gov number, NCT02261025).

Antiplatelet effects of aspirin in chronic kidney disease patients

ESSENTIALS: Chronic kidney disease (CKD) patients have a high risk of cardiovascular events. A pharmacodynamic evaluation of the effects of aspirin in 116 patients was carried out. The antiplatelet effects of aspirin are associated with impaired renal function. The optimal antithrombotic regimen in CKD patients must be investigated on a larger scale.

BACKGROUND

The pharmacodynamic response to aspirin varies significantly between individuals. Insufficient antiplatelet effects of aspirin are associated with increased risk of ischemic events. Chronic kidney disease (CKD) is suggested to affect the pharmacodynamic response to antiplatelet medication. High on-treatment platelet reactivity (HTPR) to clopidogrel has been reported to partially account for the enhanced risk of death and cardiovascular events in CKD patients. Objective To investigate the antiplatelet effects of aspirin in patients with CKD.

METHODS

We conducted a cross-sectional study in 116 patients on permanent aspirin medication. The pharmacodynamic response to aspirin was determined by arachidonic acid-induced thromboxane formation.

RESULTS

HTPR to aspirin was more frequent in patients with impaired renal function (47% vs. 22%; odds ratio, 3.16; 95% confidence interval [CI], 1.34-7.41; P = 0.008). The pharmacodynamic response to aspirin was impaired in patients with moderate/severe CKD (92; interquartile range [IQR], 282 ng mL(-1) ) as compared to patients with normal/mildly reduced renal function (36; IQR, 100 ng mL(-1) ; difference in medians, 57; CI, 5-110 ng mL(-1) ; P = 0.013). Bivariate Pearson analysis showed residual thromboxane formation to be correlated with glomerular filtration rate (R = -0.303; R(2) = 0.092; P = 0.001). Patients with CKD were older and more frequently female. Multivariate linear regression analysis revealed that the correlation was independent of age (R = -0.314; R(2) = 0.082; P = 0.002) and gender (R = -0.305; R(2) = 0.077; P = 0.006).

CONCLUSION

Renal function is correlated with pharmacodynamic response to aspirin. Patients with CKD have an increased risk of impaired antiplatelet effects of aspirin. Larger trials are needed to assess the clinical impact of this finding and investigate the optimal antithrombotic regimen in CKD patients.

Clopidogrel, prasugrel, ticagrelor or vorapaxar in patients with renal impairment: do we have a winner?

The optimal utilization of antiplatelet therapy in patients with renal impairment (RI) following acute coronary syndromes (ACS) represents an urgent, unmet and yet unsolved need with regards to the choice of agents, duration of treatment and potential dose/regimen adjustment. The lack of any large randomized trials designed and powered specifically in such high-risk patients, absence of the uniformed efficacy and safety data reporting policy to the FDA and endless overoptimistic publications based on post hoc analyses of primary trials sometimes exaggerating benefits and hiding risks, clouds reality. In addition, triaging RI patients is problematic due to ongoing kidney deterioration and the fact that such patients are prone to both vascular occlusions and bleeding. The authors summarize available FDA-confirmed evidence from the latest trials with approved antiplatelet agents, namely clopidogrel (CAPRIE, CURE, CREDO, CLARITY, CHARISMA); prasugrel (TRITON, TRILOGY); ticagrelor (PLATO, and PEGASUS); and vorapaxar (TRACER and TRA2P) in RI patient cohorts on top of aspirin as part of dual antiplatelet therapy (DAPT). We deliberately avoided any results unless they were verified by the FDA, with the exception of the recent PEGASUS, since Agency reviews are not yet available. Despite differences among the trials and DAPT choices, RI patients universally experience much higher (HR = 1.3-3.1) rates of primary endpoint events, and bleeding risks (HR = 1.7-3.6). However, only ticagrelor increases creatinine and uric acid levels above that of clopidogrel; has the worst incidence of serious adverse events, more adverse events, and inferior outcomes in patients with severe (eGFR <30 ml/min), especially in the lowest (eGFR <15 ml/min) RI subsets. Clopidogrel, prasugrel and vorapaxar appear safer. Moreover, less aggressive half dose (5 mg/daily) prasugrel and strict DAPT, are well justified in RI, but not predominantly triple strategies with vorapaxar as tested in TRA2P and especially in TRACER. In conclusion, data from clinical trials, their sub-studies and affiliated FDA reviews indicate that RI cause more vascular occlusions and bleeding in ACS patients treated with DAPT. Among the novel antiplatelet agents, prasugrel and vorapaxar, but probably not ticagrelor, offer advantage in RI patients.

Filtration of Macrophage Migration Inhibitory Factor (MIF) in Patients with End Stage Renal Disease Undergoing Hemodialysis

BACKGROUND

End stage renal disease (ESRD) patients are characterized by increased morbidity and mortality due to highest prevalence of cardiovascular disease. Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine that controls cellular signaling in human physiology, pathophysiology, and diseases. Increased MIF plasma levels promote vascular inflammation and development of atherosclerosis. We have shown that MIF is associated with vascular dysfunction in ESRD patients. Whether hemodialysis (HD) affects circulating MIF plasma levels is unknown. We here aimed to investigate whether HD influences the circulating MIF pool in ESRD patients.

METHODS AND RESULTS

An observational single-center study was conducted. MIF plasma levels in ESRD patients were assessed before, during, and after a HD session (n = 29). Healthy age-matched volunteers served as controls to compare correlations of MIF plasma levels with inflammatory plasma components (n = 20). MIF removed from the circulating blood pool could be detected in the dialysate and allowed for calculation of totally removed MIF (MIF content in dialysate 219±4 μg/HD-session). MIF plasma levels were markedly decreased 2 hour after initiation of HD (MIF plasma level pre-HD 84.8±6 ng/ml to intra-HD 61.2±5 ng/ml p<0.001) and were replenished already 20 min after termination of HD to basal levels (intra-HD 61.2±5 ng/ml to post-HD 79.8±5 ng/ml, p<0.001).

CONCLUSION

MIF is a dialyzable plasma component that is effectively filtrated during HD from the patient blood pool in large amounts. After removal of remarkable amounts of MIF during a single HD session, MIF plasma pool is early reconstituted after termination of HD from unknown sources.

Liver Function is Associated With Response to Clopidogrel Therapy in Patients Undergoing Angioplasty and Stenting

The relationship between liver function and clopidogrel response has not been studied so far. We therefore sought to investigate the associations between 3 parameters of liver synthesis and on-treatment platelet reactivity to adenosine diphosphate in patients on dual antiplatelet therapy. On-treatment platelet reactivity was determined by the VerifyNow P2Y12 assay in 316 patients undergoing angioplasty with stent implantation for cardiovascular disease. Cholinesterase, serum albumin, and total cholesterol levels were measured by internationally standardized assays in the hospital's central laboratory. On-treatment platelet reactivity by the VerifyNow P2Y12 assay correlated inversely with cholinesterase, serum albumin, and total cholesterol levels (all P ≤ .02). The inverse associations of cholinesterase and serum albumin levels with platelet reactivity remained significant after adjustment for cytochrome P450 loss-of-function polymorphisms and other factors that were previously associated with high on-treatment residual platelet reactivity (HRPR; both P < .05). Patients without HRPR by the VerifyNow P2Y12 assay had significantly higher levels of serum albumin and total cholesterol than patients with HRPR (both P = .008). In conclusion, liver function is associated with response to clopidogrel therapy in patients undergoing angioplasty and stenting for cardiovascular disease.

Effects of lipid-lowering treatment on circulating microparticles in patients with diabetes mellitus and chronic kidney disease

BACKGROUND

Elevated levels of circulating microparticles (MPs) may contribute to the high cardiovascular risk in diabetes mellitus (DM) and chronic kidney disease (CKD). Therefore, we investigated the effects of lipid-lowering treatment (LLT) with simvastatin alone (S) or with ezetimibe (S+E) on MPs in DM patients with or without CKD.

METHODS

After a placebo run-in period, 18 DM patients with an estimated glomerular filtration rate (eGFR) of 15-59 mL/min (CKD stages 3-4) (DM-CKD) and 21 DM patients with eGFR >75 mL/min (DM-only) were treated with S and S+E in a randomized, double-blind, crossover study. MPs from platelets, monocytes and endothelial cells (PMPs, MMPs and EMPs), and their expression of phosphatidylserine (PS), P-selectin, CD40 ligand (CD40L) and tissue factor (TF) were measured by flow cytometry.

RESULTS

At baseline, all types of MPs, except TF-positive MMPs, were elevated in DM-CKD compared with DM-only patients. All MPs, regardless of origin and phenotype, were inversely correlated with eGFR. S reduced the expression of P-selectin, TF and CD40L on PMPs and of TF on MMPs in both patient groups. S+E had no further effect. S also reduced total PS-positive procoagulant MPs, PMPs and MMPs in DM-CKD but not in DM-only patients.

CONCLUSIONS

DM patients with CKD stages 3-4 had elevated PMPs, EMPs and MMPs compared with DM patients with normal GFR. Simvastatin reduced procoagulant MPs, MMPs and PMPs in DM-CKD patients, suggesting a beneficial reduction of hypercoagulability in this high-risk patient group. Differences between DM-CKD and DM-only patients were counteracted by LLT.

Differential impact of peripheral endothelial dysfunction on subsequent cardiovascular events following percutaneous coronary intervention between chronic kidney disease (CKD) and non-CKD patients

Chronic kidney disease (CKD) status might modify the predictive effect of peripheral endothelial dysfunction on cardiovascular events after percutaneous coronary intervention (PCI). The aim of this study was to examine the differential effect of peripheral endothelial dysfunction on clinical outcome after PCI between CKD and non-CKD patients. We conducted a cohort study of 435 patients following PCI. CKD was defined as estimated glomerular filtration rate <60 mL/min/1.73 m(2). Peripheral endothelial dysfunction was examined using reactive hyperemia-peripheral arterial tonometry index (RHI), and we divided patients into low- and high-natural logarithmic RHI (Ln-RHI) group. The endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, ischemic stroke, hospitalization due to unstable angina pectoris, and coronary revascularization. A total of 56 patients had a cardiovascular event. Patients who suffered a cardiovascular event had significantly lower Ln-RHI than other patients in the non-CKD group (0.46 ± 0.18 versus 0.60 ± 0.25; P = 0.002). Kaplan-Meier analysis demonstrated a significantly higher probability of cardiovascular events in low Ln-RHI patients in the non-CKD group (log-rank test: P = 0.003). Multivariate Cox proportional hazards analysis identified Ln-RHI as an independent and significant predictor of future cardiovascular events in the non-CKD group (HR: 0.096; 95 % CI 0.02-0.47; P = 0.004) but not in the CKD group. There was a differential effect of peripheral endothelial dysfunction on clinical outcome after PCI between CKD and non-CKD patients, and peripheral endothelial dysfunction significantly correlates with subsequent cardiovascular events after PCI in non-CKD patients.

Prevalence and Impact of High Platelet Reactivity in Chronic Kidney Disease

Background—

Chronic kidney disease (CKD) is associated with increased rates of adverse events after percutaneous coronary intervention. We sought to determine the impact of CKD on platelet reactivity in clopidogrel-treated patients and whether high platelet reactivity (HPR) confers a similar or differential risk for adverse events among patients with CKD and non-CKD.

Methods and Results—

We performed a post hoc analysis of the Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents (ADAPT-DES) registry, which included 8582 patients undergoing percutaneous coronary intervention with drug-eluting stents and platelet function testing using the VerifyNow assay. We compared HPR and its impact on ischemic and bleeding events >2 years among patients with CKD and non-CKD. Patients with CKD (n=1367) were older, more often female, diabetic, and had lower ejection fraction compared with their non-CKD counterparts (n=7043). Although HPR prevalence increased with worsening renal function in unadjusted analyses, these associations were no longer present after adjustment. Major adverse cardiac event rates at 2 years among those without CKD or HPR, HPR alone, CKD alone, and both CKD and HPR were 9.0%, 11.2%, 13.3%, and 17.5%, respectively ( P <0.001). Associations between HPR and adverse events were uniform across CKD strata without evidence of interaction.

Conclusions—

HPR is more common among those with versus without CKD, an association that is attributable to confounding risk factors that are more prevalent in CKD. The impact of HPR on ischemic and bleeding events is similar irrespective of CKD status.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00638794.

Interleukin-6 and asymmetric dimethylarginine are associated with platelet activation after percutaneous angioplasty with stent implantation

Data linking in vivo platelet activation with inflammation and cardiovascular risk factors are scarce. Moreover, the interrelation between endothelial dysfunction as early marker of atherosclerosis and platelet activation has not been studied, so far. We therefore sought to investigate the associations of inflammation, endothelial dysfunction and cardiovascular risk factors with platelet activation and monocyte-platelet aggregate (MPA) formation in 330 patients undergoing angioplasty with stent implantation for atherosclerotic cardiovascular disease. P-selectin expression, activation of glycoprotein IIb/IIIa and MPA formation were determined by flow cytometry. Interleukin (IL)-6, high sensitivity C-reactive protein and asymmetric dimethylarginine (ADMA) were measured by commercially available assays. IL-6 was the only parameter which was independently associated with platelet P-selectin expression and activated GPIIb/IIIa as well as with leukocyte-platelet interaction in multivariate regression analysis (all p<0.05). ADMA was independently associated with GPIIb/IIIa activation (p<0.05). Patients with high IL-6 exhibited a significantly higher expression of P-selectin than patients with low IL-6 (p=0.001), whereas patients with high ADMA levels showed a more pronounced activation of GPIIb/IIIa than patients with low ADMA (p=0.003). In conclusion, IL-6 and ADMA are associated with platelet activation after percutaneous angioplasty with stent implantation. It remains to be established whether they act prothrombotic and atherogenic themselves or are just surrogate markers for atherosclerosis with concomitant platelet activation.

Predictors of outcomes of contrast-induced acute kidney injury after percutaneous coronary intervention in patients with chronic kidney disease

Contrast-induced acute kidney injury (CI-AKI) is a serious complication that is difficult to predict in patients with chronic kidney disease (CKD) undergoing percutaneous coronary intervention (PCI). The aim of this study was to investigate predictors and clinical outcomes of CI-AKI in patients with CKD after PCI. A total of 297 patients with CKD who underwent PCI from September 2006 to December 2011 were enrolled. CI-AKI was defined as serum creatinine level either ≥25% or ≥0.5 mg/dl from baseline within 72 hours after PCI. The primary outcome was all-cause death. The median follow-up duration was 26 months (interquartile range 12 to 40), and CI-AKI occurred in 55 patients (19%). In multivariate logistic regression analyses, the development of CI-AKI was associated with female gender, left ventricular systolic dysfunction, acute myocardial infarction, PCI for left main disease, serum hemoglobin level, and a contrast volume to creatinine clearance ratio >6.0. The development of CI-AKI was significantly associated with increased in-hospital mortality (18.2% vs 3.7%, p = 0.001). Cox proportional-hazard analysis showed that the incidence of all-cause death was significantly higher in patients who developed CI-AKI than in those without CI-AKI (41.8% vs 16.1%, adjusted hazard ratio 3.0, 95% confidence interval 1.6 to 5.6, p <0.001). In conclusion, female gender, left ventricular systolic dysfunction, acute myocardial infarction, PCI for left main disease, serum hemoglobin level, and contrast volume to creatinine clearance ratio >6.0 are independent predictors of CI-AKI. The development of CI-AKI is significantly associated with increased in-hospital and long-term adverse clinical outcomes in patients with CKD undergoing PCI.

Dipstick proteinuria is an independent predictor of high on treatment platelet reactivity in patients on clopidogrel, but not aspirin, admitted for major adverse cardiovascular events

The effectiveness of aspirin and clopidogrel in patients with chronic kidney disease (CKD) suffering from acute cardiovascular events is unclear. High on treatment platelet reactivity (HTPR) has been associated with worse outcomes. Here, we assessed the association of dipstick proteinuria (DP) and renal function on HTPR and clinical outcomes. Retrospective cohort analysis of 261 consecutive, non-dialysis patients admitted for Major Adverse Cardiovascular Events (MACE) that had VerifyNow P2Y12 and VerifyNow Aspirin assays performed. HTPR was defined as P2Y12 reactivity unit (PRU) > 208 for clopidogrel and aspirin reaction units (ARU) > 550 for aspirin. Renal function was classified based on the estimated glomerular filtration rate (eGFR), and dipstick proteinuria was defined as ≥ 30 mg/dl of albumin detected on a spot analysis. All cause mortality, readmissions, and cardiac catheterizations were reviewed over 520 days. In patients on clopidogrel (n = 106), DP was associated with HTPR, independent of eGFR, diabetes mellitus, smoking or use of proton pump inhibitor (AOR = 4.76, p = 0.03). In patients with acute coronary syndromes, HTPR was associated with more cardiac catheterizations (p = 0.009) and readmissions (p = 0.032), but no differences in in-stent thrombosis or re-stenosis were noted in this cohort. In patients on aspirin (n = 155), no associations were seen between DP and HTPR. However, all cause mortality was significantly higher with HTPR in this group (p = 0.038). In this cohort, DP is an independent predictor of HTPR in patients on clopidogrel, but not aspirin, admitted to the hospital for MACE.

Human neutrophil α-defensins are associated with adenosine diphosphate-inducible neutrophil-platelet aggregate formation and response to clopidogrel in patients with atherosclerosis

Human neutrophil α-defensins (HNPs) are antimicrobial peptides stored primarily in the azurophilic granules of polymorphonuclear leukocytes. Recently, it was shown that HNPs act as platelet agonists. We hypothesized that HNP levels are associated with the formation of neutrophil-platelet aggregates, and that they influence the response to clopidogrel therapy. HNP levels were determined by a commercially available enzyme-linked immunosorbent assay in 305 patients undergoing angioplasty and stenting for atherosclerotic cardiovascular disease. Neutrophil-platelet aggregates were measured by flow cytometry, and on-treatment platelet reactivity was determined using the VerifyNow P2Y12 and aspirin assays. HNP levels did not correlate with the formation of neutrophil-platelet aggregates in vivo (r = 0.05, P = 0.4). In contrast, HNP levels correlated significantly with adenosine diphosphate (ADP)-inducible neutrophil-platelet aggregate formation (r = 0.13, P = 0.04). On-treatment platelet reactivity by the VerifyNow P2Y12 assay was significantly more pronounced in patients with high HNP levels compared with patients with low HNP levels (211 P2Y12 reaction units [PRU; range, 143-293 PRU] vs 181 PRU [range, 129-237 PRU], P = 0.009). This association remained significant after adjusting for high-sensitivity C-reactive protein and interleukin 6 by multivariate regression analysis (P = 0.007). Moreover, high on-treatment residual platelet reactivity by the VerifyNow P2Y12 assay was more frequent in patients with high HNP levels than in patients with low HNP levels (40% vs 26.6%, P = 0.01). In conclusion, HNP levels are associated with ADP-inducible neutrophil-platelet aggregate formation and clopidogrel-mediated platelet inhibition. High levels of HNPs may, in part, be responsible for the observed response variability to clopidogrel.

Low-dose aspirin for prevention of cardiovascular disease in patients with chronic kidney disease

Background

Chronic kidney disease (CKD) is a major risk factor for the development of cardiovascular disease (CVD). Previous trials have investigated the effects of low-dose aspirin on CVD prevention in patients with diabetes; however, patients with CKD were not examined. The role of aspirin in diabetics is controversial, and the available literature is contradictory. Therefore, we studied whether low-dose aspirin would be beneficial for patients with CKD, a group that is at high risk for CVD.

Method

From a total of 25340 patients with CKD, 1884 recipients of low-dose aspirin (100 mg/day) were paired 1∶1 with non-recipients for analysis using propensity score matching. The primary endpoint was the development of atherosclerotic CVD, including coronary arterial disease, stroke, and peripheral arterial disease. Secondary endpoints included death from any cause, bleeding events, doubling of serum creatinine, and renal death.

Results

The incidence of a primary endpoint of any atherosclerotic CVD was significantly higher in the aspirin users than in the non-users (P<0.001). Secondary endpoints, including all-cause mortality and composite bleeding events, were not significantly different between the aspirin users and the non-users. However, the doubling of serum creatinine levels (P = 0.001) and renal death (P = 0.042) were significantly associated with the use of aspirin.

Conclusion

These results suggest that the use of low-dose aspirin in patients with CKD may have harmful consequences related to the development of CVD and renal progression.