The efficacy and safety of short- and long-term dual antiplatelet therapy in patients with mild or moderate chronic kidney disease: results from the Clopidogrel for the Reduction of Events During Observation (CREDO) trial

Impact of chronic kidney disease on long-term clinical outcomes after percutaneous coronary intervention with drug-eluting or bare-metal stents

Chronic kidney disease (CKD) is associated with adverse outcomes after coronary bare-metal stent (BMS) and drug-eluting stent (DES) implantation, but it is unclear which stent type is associated with lower risk for morbidity and mortality in this population. Uniform treatment standards during coronary stent implantation and a median follow-up period of 2.8 years characterize the FReIburg STent (FRIST) registry, designed as a long-term outcome evaluation of a single tertiary referral cardiovascular center. CKD, defined as creatinine clearance <60 mL/min, was present at baseline in 180 (12%) of 1502 consecutive patients undergoing coronary stent intervention. Patients received first-generation DES (n = 117) or BMS (n = 63). Kaplan-Meier and multivariate Cox model analyses were applied to compare survival rates and adjust for existing clinical, procedural, and angiographic differences between the patients. The primary end point was mortality (cardiac and noncardiac death) and secondary end points were recurrent myocardial infarction, stent thrombosis, target vessel revascularization, sepsis, and major bleeding. Patients with a glomerular filtration rate <60 mL/min had a higher mortality rate (28.3% vs. 10.1%, P < 0.001) than patients with a good renal function. In patients with CKD, there was no difference in mortality rates in the BMS vs. the DES group (hazard ratio, 0.971; 95% confidence interval, 0.48-1.954). In summary, patients with CKD have significantly higher rates of death, but there appears to be no difference in long-term clinical outcomes of first-generation DES compared with BMS implantation during primary percutaneous coronary intervention.

Stent thrombosis in patients with chronic kidney disease

Chronic kidney disease is a strong predictor of adverse cardiac events, including death, myocardial infarction and stent thrombosis (ST), after percutaneous coronary intervention. In the past few years, the development of new therapeutic strategies (including both drugs and devices) and a more complete understanding of the pathophysiology and predictive factors of thrombosis have led to a significant reduction of this complication. Despite this, ST still remains a dramatic event due to its morbidity and mortality. Further efforts should be pursued to identify patients at high risk of ST in order to adopt a more effective preventive strategy. This review sought to examine the total weight of evidence regarding ST with the use of drug-eluting stents in patients with chronic kidney disease.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Chronic kidney disease (CKD) is prevalent and affects an ever-increasing proportion of patients presenting with acute coronary syndrome (ACS). Patients with CKD have a higher risk of ACS and significantly higher mortality, and are also predisposed to increased bleeding complications. Antiplatelet and antithrombotic drugs form the bedrock of management of patients with ACS. Most randomized trials of these drugs exclude patients with CKD, and current guidelines for management of these patients are largely based on these trials. We aim to review the safety and efficacy of these drugs in patients with CKD presenting with ACS.

ST-Elevation Acute Coronary Syndromes in the Platelet Inhibition and Patient Outcomes (PLATO) Trial

Background—

Ticagrelor, when compared with clopidogrel, reduced the 12-month risk of vascular death/myocardial infarction and stroke in patients with ST-elevation acute coronary syndromes intended to undergo primary percutaneous coronary intervention in the PLATelet inhibition and patient Outcomes (PLATO) trial. This prespecified ECG substudy explored whether ticagrelor's association with vascular death and myocardial infarction within 1 year would be amplified by (1) the extent of baseline ST shift and (2) subsequently associated with fewer residual ST changes at hospital discharge.

Methods and Results—

ECGs were evaluated centrally in a core laboratory in 3122 ticagrelor- and 3084 clopidogrel-assigned patients having at least 1 mm ST-elevation in 2 contiguous leads as identified by site investigators on the qualifying ECG. Patients with greater ST-segment shift at baseline had higher rates of vascular death/myocardial infarction within 1 year. Among those who also had an ECG at hospital discharge (n=4798), patients with ≥50% ΣST-deviation (ΣST-dev) resolution had higher event-free survival than those with incomplete resolution (6.4% versus 8.8%, adjusted hazard ratio 0.69 (0.54–0.88), P =0.003). The extent of ΣST-dev resolution was similar irrespective of treatment assignment. The benefit of ticagrelor versus clopidogrel on clinical events was consistent irrespective of the extent of baseline ΣST-dev ( P (interaction)=0.728). When stratified according to conventional times from symptom onset, ie, ≤3 hours, 3 to 6 hours, >6 hours, the extent of baseline ΣST-dev declined progressively over time. As time from symptom onset increased beyond 3 hours, the benefit of ticagrelor appeared to be more pronounced; however, the interaction between time and treatment was not significant ( P =0.175).

Conclusions—

Ticagrelor did not modify ΣST-dev resolution at discharge nor was its benefit affected by the extent of baseline ΣST-dev. These hypothesis-generating observations suggest that the main effects of ticagrelor may not relate to the rapidity or the completeness of acute reperfusion, but rather the prevention of recurrent vascular events by more powerful platelet inhibition or other mechanisms.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00391872.

Platelet reactivity in patients with chronic kidney disease receiving adjunctive cilostazol compared with a high-maintenance dose of clopidogrel: results of the effect of platelet inhibition according to clopidogrel dose in patients with chronic kidney disease (PIANO-2 CKD) randomized study

BACKGROUND

Chronic kidney disease (CKD) is a factor of low response to clopidogrel. We sought to assess the functional impact of cilostazol in CKD patients with undergoing hemodialysis.

METHODS

Seventy-four patients with CKD undergoing hemodialysis and percutaneous coronary intervention were enrolled. Patients were randomly assigned to receive clopidogrel (75 mg/d [group 1, n = 24]), high-maintenance dose of clopidogrel (150 mg/d [group 2, n = 25]), or clopidogrel (75 mg/d) with cilostazol (200 mg/d [group 3, n = 25]) for 14 days. Another 50 patients with normal renal function undergoing percutaneous coronary intervention were treated with 75 mg of clopidogrel and served as the control group. Platelet function was evaluated before and after antiplatelet therapy with light transmittance aggregometry and with VerifyNow P2Y12 assay (Accumetrics, San Diego, CA). Platelet activation markers (soluble CD40 ligand and soluble P-selectin) were also assessed.

RESULTS

The baseline platelet function measurements were similar in the 3 groups of patients; however, the CKD groups had significantly higher platelet aggregation activity compared with the control groups. The rate of high on-treatment platelet reactivity was significantly lower in group 3 than in groups 1 and 2 (10% vs 43% vs 32%, respectively; P < .05). After 14 days of antiplatelet therapy, the changes in plasma soluble CD40 ligand and soluble P-selectin levels were significantly higher in group 3 compared with groups 1 and 2 (P < .01); however, there were no significant differences in platelet function and activation markers between groups 1 and 2.

CONCLUSIONS

Adjunctive cilostazol improves platelet inhibition compared with 75 or 150 mg of clopidogrel in CKD patients undergoing hemodialysis.

The use of antiplatelet therapy in the outpatient setting: Canadian Cardiovascular Society Guidelines Executive Summary

Antiplatelet agents are a cornerstone of therapy for patients with atherosclerotic vascular disease. There is presently a lack of comprehensive guidelines focusing on the use of antiplatelet drugs in patients currently manifesting or at elevated risk of cardiovascular disease. The Canadian Antiplatelet Therapy Guidelines Committee reviewed existing disease-based guidelines and subsequently published literature and used expert opinion and review to develop guidelines on the use of antiplatelet therapy in the outpatient setting. This Executive Summary provides an abbreviated version of the principal recommendations. Antiplatelet therapy appears to be generally underused, perhaps in part because of a lack of clear, evidence-based guidance. Here, we provide specific guidelines for secondary prevention in patients discharged from hospital after acute coronary syndromes, percutaneous coronary intervention, or coronary artery bypass grafting; patients with a history of transient cerebral ischemic events or strokes; and patients with peripheral arterial disease. Issues related to primary prevention are also addressed, in addition to special clinical contexts such as diabetes, heart failure, chronic kidney disease, pregnancy or lactation, and perioperative management. Recommendations are provided regarding pharmacologic interactions that may occur during combination therapy with warfarin, clopidogrel, and proton-pump inhibitors, or aspirin and nonsteroidal anti-inflammatory drugs, as well as for the management of bleeding complications. The complete guidelines document is published as a supplementary issue of the Canadian Journal of Cardiology and is available at http://www.ccs.ca/.

Low responsiveness to clopidogrel increases risk among CKD patients undergoing coronary intervention

Patients with CKD are at higher risk for major events after percutaneous coronary intervention (PCI) compared with subjects with normal renal function. The aims of this study were to evaluate responsiveness to clopidogrel in patients with CKD and to examine the effect of antiplatelet drug response on post-PCI outcome. We retrospectively evaluated a consecutive cohort of 1567 patients with symptomatic coronary artery disease undergoing PCI, 648 (41%) of whom had stage 3 to 5 CKD. We assessed responsiveness to clopidogrel by ADP-induced platelet aggregation after oral administration of a 600-mg clopidogrel loading dose and 100 mg of aspirin. In a multivariate survival analysis that included 1335 (85%) of the cohort, stage 3 to 5 CKD and low response to clopidogrel were independent predictors of the primary end point (composite of myocardial infarction, ischemic stroke, and death within 1 year). In summary, a low response to clopidogrel might be an additional risk factor for the poorer outcomes in patients with stage 3 to 5 CKD compared with patients with better renal function.

Aspirin is beneficial in hypertensive patients with chronic kidney disease: a post-hoc subgroup analysis of a randomized controlled trial

OBJECTIVES

The purpose of this study was to determine the benefit and risk associated with antiplatelet therapy in the chronic kidney disease (CKD) population.

BACKGROUND

Cardiovascular and possibly bleeding risks are elevated in patients with CKD. The balance of benefit and harm associated with antiplatelet therapy remains uncertain.

METHODS

The HOT (Hypertension Optimal Treatment) study randomly assigned participants with diastolic hypertension to aspirin (75 mg) or placebo. Study treatment effects were calculated using univariate proportional hazards regression models stratified by baseline estimated glomerular filtration rate (eGFR) with trends tested by adding interaction terms. End points included major cardiovascular events, total mortality, and major bleeding.

RESULTS

The study included 18,597 participants treated for 3.8 years. Baseline eGFR was < 60 ml/min/1.73 m(2) in 3,619 participants. Major cardiovascular events were reduced by 9% (95% confidence interval [CI]: -9% to 24%), 15% (95% CI: -17% to 39%), and 66% (95% CI: 33% to 83%) for patients with baseline eGFR of ≥ 60, 45 to 59, and < 45 ml/min/1.73 m(2), respectively (p trend = 0.03). Total mortality was reduced by 0% (95% CI: -20% to 17%), 11% (95% CI: -31% to 40%), and 49% (95% CI: 6% to 73%), respectively (p trend = 0.04). Major bleeding events were nonsignificantly greater with lower eGFR (hazard ratio [HR]: 1.52 [95% CI: 1.11 to 2.08], HR: 1.70 [95% CI: 0.74 to 3.88], and HR: 2.81 [95% CI: 0.92 to 8.84], respectively; p trend = 0.30). Among every 1,000 persons with eGFR < 45 ml/min/1.73 m(2) treated for 3.8 years, 76 major cardiovascular events and 54 all-cause deaths will be prevented while 27 excess major bleeds will occur.

CONCLUSIONS

Aspirin therapy produces greater absolute reduction in major cardiovascular events and mortality in hypertensive patients with CKD than with normal kidney function. An increased risk of major bleeding appears to be outweighed by the substantial benefits.

Ticagrelor versus clopidogrel in acute coronary syndromes in relation to renal function: results from the Platelet Inhibition and Patient Outcomes (PLATO) trial

BACKGROUND

Reduced renal function is associated with a poorer prognosis and increased bleeding risk in patients with acute coronary syndromes and may therefore alter the risk-benefit ratio with antiplatelet therapies. In the Platelet Inhibition and Patient Outcomes (PLATO) trial, ticagrelor compared with clopidogrel reduced the primary composite end point of cardiovascular death, myocardial infarction, and stroke at 12 months but with similar major bleeding rates.

METHODS AND RESULTS

Central laboratory serum creatinine levels were available in 15 202 (81.9%) acute coronary syndrome patients at baseline, and creatinine clearance, estimated by the Cockcroft Gault equation, was calculated. In patients with chronic kidney disease (creatinine clearance <60 mL/min; n=3237), ticagrelor versus clopidogrel significantly reduced the primary end point to 17.3% from 22.0% (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.65 to 0.90) with an absolute risk reduction greater than that of patients with normal renal function (n=11 965): 7.9% versus 8.9% (HR, 0.90; 95% CI, 0.79 to 1.02). In patients with chronic kidney disease, ticagrelor reduced total mortality (10.0% versus 14.0%; HR, 0.72; 95% CI, 0.58 to 0.89). Major bleeding rates, fatal bleedings, and non-coronary bypass-related major bleedings were not significantly different between the 2 randomized groups (15.1% versus 14.3%; HR, 1.07; 95% CI, 0.88 to 1.30; 0.34% versus 0.77%; HR, 0.48; 95% CI, 0.15 to 1.54; and 8.5% versus 7.3%; HR, 1.28; 95% CI, 0.97 to 1.68). The interactions between creatinine clearance and randomized treatment on any of the outcome variables were nonsignificant.

CONCLUSIONS

In acute coronary syndrome patients with chronic kidney disease, ticagrelor compared with clopidogrel significantly reduces ischemic end points and mortality without a significant increase in major bleeding but with numerically more non-procedure-related bleeding.

CLINICAL TRIAL REGISTRATION

URL:http://www.clinicatrials.gov. Unique identifier: NCT00391872.

Therapeutic strategies for heart failure in cardiorenal syndromes

Cardiorenal syndromes are disorders of the heart and kidneys whereby acute or long-term dysfunction in one organ may induce acute or long-term dysfunction of the other. The management of cardiovascular diseases and risk factors may influence, in a beneficial or harmful way, kidney function and progression of kidney injury. In this review, we assess therapeutic strategies and discuss treatment options for the management of patients with heart failure with decreased kidney function and highlight the need for future high-quality studies in patients with coexisting heart and kidney disease.

Impact of chronic kidney disease on platelet function profiles in diabetes mellitus patients with coronary artery disease taking dual antiplatelet therapy

OBJECTIVES

We sought to assess the impact of renal function on platelet reactivity in patients with diabetes mellitus (DM) and coronary artery disease on aspirin and clopidogrel therapy.

BACKGROUND

Diabetes mellitus is a key risk factor for chronic kidney disease (CKD). In aspirin-treated DM patients the presence of moderate/severe CKD is associated with reduced clinical efficacy of adjunctive clopidogrel therapy. Whether these findings may be attributed to differences in clopidogrel-induced effects is unknown.

METHODS

This was a cross-sectional observational study in which DM patients taking maintenance aspirin and clopidogrel therapy were studied. Patients were categorized into 2 groups according to the presence or absence of moderate/severe CKD. Platelet aggregation after adenosine diphosphate (ADP) and collagen stimuli were assessed with light transmittance aggregometry and defined patients with high post-treatment platelet reactivity (HPPR). Markers of platelet activation, including glycoprotein IIb/IIIa activation and P-selectin expression, were also determined using flow cytometry.

RESULTS

A total of 306 DM patients were analyzed. Patients with moderate/severe CKD (n = 84) had significantly higher ADP-induced (60 +/- 13% vs. 52 +/- 15%, p = 0.001) and collagen-induced (49 +/- 20% vs. 41 +/- 20%, p = 0.004) platelet aggregation compared with those without (n = 222). After adjustment for potential confounders, patients with moderate/severe CKD were more likely to have HPPR after ADP (adjusted odds ratio: 3.8, 95% confidence interval: 1.7 to 8.5, p = 0.001) and collagen (adjusted odds ratio: 2.4; 95% confidence interval: 1.1 to 5.4; p = 0.029) stimuli. Markers of platelet activation were significantly increased in patients with HPPR.

CONCLUSIONS

In DM patients with coronary artery disease taking maintenance aspirin and clopidogrel therapy, impaired renal function is associated with reduced clopidogrel-induced antiplatelet effects and a greater prevalence of HPPR.

Use of drug-eluting stents in patients with coronary artery disease and renal insufficiency

Renal insufficiency (RI) has been shown to be associated with increased major adverse cardiovascular events after percutaneous coronary intervention. We reviewed the impact of RI on the pathogenesis of coronary artery disease and outcomes after percutaneous coronary intervention in the form of drug-eluting stent (DES) implantation in these high-risk patients. We searched the English-language literature indexed in MEDLINE, Scopus, and EBSCO Host research databases from 1990 through January 2009, using as search terms coronary revascularization, drug-eluting stent, and renal insufficiency. Studies that assessed DES implantation in patients with various degrees of RI were selected for review. Most of the available data were extracted from observational studies, and data from randomized trials formed the basis of a post hoc analysis. The outcomes after coronary revascularization were less favorable in patients with RI than in those with normal renal function. In patients with RI, DES implantation yielded better outcomes than did use of bare-metal stents. Randomized trials are needed to define optimal treatment of these high-risk patients with coronary artery disease.

Relationship between baseline inflammatory markers, antiplatelet therapy, and adverse cardiac events after percutaneous coronary intervention: an analysis from the clopidogrel for the reduction of events during observation trial

BACKGROUND

We evaluated patients undergoing percutaneous coronary intervention to assess the predictive value of high-sensitivity C-reactive protein (hs-CRP) and pregnancy-associated plasma protein-A (PAPP-A) on adverse cardiac outcomes and the effect of antiplatelet therapy on these outcomes.

METHODS AND RESULTS

Baseline blood samples were available on 1468 CREDO (Clopidogrel for the Reduction of Events During Observation) patients for hs-CRP testing and 1096 patients for PAPP-A testing. The 1-year primary end point was the composite incidence of death, myocardial infarction, or stroke. Patients in the highest 2 tertiles of hs-CRP had more events compared with the lowest tertile (11.4% versus 6.4%, P=0.003). Treatment with clopidogrel reduced the 1-year composite end point for patients in the highest 2 tertiles of hs-CRP (9.1% clopidogrel versus 13.5% placebo, P=0.04) but not in the lowest tertile. Elevated PAPP-A levels were associated with a trend toward more events at 1 year that did not reach statistical significance. Patients in the highest 2 tertiles of PAPP-A randomized to clopidogrel had fewer events (7.3% clopidogrel versus 13.1% placebo, P=0.01), but no benefit was seen in the lowest tertile. A 46% risk reduction with randomization to clopidogrel was seen in patients in the highest 2 tertiles of both biomarkers (8.7% versus 16.2%, P=0.02).

CONCLUSIONS

Patients undergoing nonurgent percutaneous coronary intervention who have elevated hs-CRP and PAPP-A have an increased incidence of adverse cardiovascular events. The clinical benefit of adding clopidogrel to aspirin seems greater in those with increased levels of these inflammatory biomarkers.

Coronary stent thrombosis in patients with chronic renal insufficiency

Renal insufficiency (RI) is a strong predictor of unfavorable outcomes after percutaneous coronary intervention (PCI). After PCI, stent thrombosis (ST) is a considerable concern. The risk of ST in RI has not been independently evaluated before. The mechanism of ST is frequently related to dual antiplatelet underuse. We reviewed the publications listed on Medline, Scopus, and EBSCO Host research database in the last two decades to identify the risk of ST in patients with RI. There are no enough data on the incidence of ST in RI patients. Platelet reactivity, appropriate period of dual antiplatelet therapy, coronary anatomy, selection of stent, and patient compliance are vital issues that warrant detailed evaluation in RI patients. Moreover, prospective trials and new therapeutic strategies are needed for proper assessment and management of ST in high-risk patients.

Cardiovascular risk and management in chronic kidney disease

Chronic kidney disease (CKD) is associated with accelerated progression of cardiovascular disease, perhaps because patients with CKD have a high burden of traditional cardiovascular risk factors in addition to a range of nontraditional risk factors such as inflammation and abnormal metabolism of calcium and phosphate. Although the cardiovascular burden of CKD is well documented, potentially beneficial therapies are sometimes underused in patients with stage 3-4 CKD and are rarely studied in patients on dialysis. In this Review, we describe the epidemiology of cardiovascular disease in patients with stage 3-5 CKD (excluding kidney transplant recipients) and outline cardiovascular risk factors that are relevant in this population; we then discuss the implications of this knowledge for the optimal management of cardiovascular risk in this setting. Finally, we highlight opportunities for further research.

Antiplatelet medications in hemodialysis patients: a systematic review of bleeding rates

BACKGROUND AND OBJECTIVES

Patients with end stage renal disease (ESRD) are often prescribed antiplatelet medications. However, these patients are also at increased risk of bleeding compared with the general population, and an aim was made to quantify this risk with antiplatelet agents.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A systematic review of the literature (Medline, EMBASE, Cochrane CENTRAL and Google Scholar databases) was done to determine the bleeding risk in ESRD patients prescribed antiplatelet therapy. The secondary outcome was the effect on access thrombosis. All case series, cohort studies and clinical trials were considered if they included ten or more ESRD patients, assessed bleeding risk with antiplatelet agents, and lasted for more than 3 mo.

RESULTS

Sixteen studies, including 40,676 patients, were identified that met predefined inclusion criteria. Due to study heterogeneity and weaknesses in methodology, bleeding rates were not pooled across studies. However, the bleeding risk appears to be increased for hemodialysis patients treated with combination antiplatelet therapy. The results are mixed for studies using a single antiplatelet agent. Antiplatelet agents appear to be effective in preventing shunt and central venous catheter thrombosis, but not for preventing thrombosis of arteriovenous grafts.

CONCLUSION

The risks and benefits of antiplatelet agents in ESRD patients remain poorly defined. Until a clinical trial addresses this in the dialysis population, individual risk stratification taking into account the increased risk of bleeding should be considered before initiating antiplatelet agents, especially in combination therapy.

Clinical outcomes of patients with diabetic nephropathy randomized to clopidogrel plus aspirin versus aspirin alone (a post hoc analysis of the clopidogrel for high atherothrombotic risk and ischemic stabilization, management, and avoidance [CHARISMA] trial)

No prospective randomized trial has specifically examined the long-term outcomes of clopidogrel use in patients with chronic kidney disease. This study aimed to determine the risks and benefits of long-term clopidogrel administration in patients with diabetic nephropathy, the most common form of chronic kidney disease. We performed a post hoc analysis of the CHARISMA trial, which randomly assigned patients without active acute coronary syndrome, but with established atherosclerotic disease (symptomatic) or multiple risk factors for atherosclerotic disease (asymptomatic), to clopidogrel plus aspirin versus placebo plus aspirin. All CHARISMA patients (n = 15,603) were separated into the 3 groups: nondiabetic patients, diabetic patients without nephropathy, and diabetic patients with nephropathy. Within each group, outcomes of patients randomly assigned to clopidogrel were compared with those of patients randomly assigned to placebo. Outcomes in the prespecified CHARISMA subgroups of asymptomatic and symptomatic patients were also compared with respect to study drug assignment and nephropathy status. Patients with nephropathy who received clopidogrel had no difference in bleeding, but experienced significantly increased cardiovascular (CV) and overall mortality compared with those randomly assigned to placebo. There were no differences in bleeding, overall mortality, or CV mortality for nondiabetic or diabetic patients without nephropathy who received clopidogrel versus placebo. In the asymptomatic cohort, patients with nephropathy randomly assigned to clopidogrel had significantly increased overall and CV mortality compared with placebo, whereas asymptomatic patients without nephropathy randomly assigned to clopidogrel had no significant mortality difference compared with placebo. In conclusion, this post hoc analysis suggested that clopidogrel may be harmful in patients with diabetic nephropathy. Additional studies are needed to investigate this possible interaction.

New insights into stroke in chronic kidney disease

Patients with chronic kidney disease (CKD) are predisposed to stroke, especially as the estimated glomerular filtration rate decreases. This update reviews the pathologic mechanisms particular to this stroke population. The treatment for primary and secondary prevention of stroke is reviewed with respect to antiplatelet agents, anticoagulants, surgery, and carotid stenting. The control of chronic hypertension is particularly important in reducing stroke risk in CKD. In patients with prior stroke from atherosclerosis, antiplatelet agents are most beneficial in reducing secondary stroke risk. Those with atrial fibrillation and CKD may benefit from warfarin anticoagulation. Statins in CKD for stroke reduction in diabetics receiving dialysis are not useful, and the data are pending for their use in stroke reduction in the general CKD population. In carefully selected cases, carotid endarterectomy can be a treatment. The data on carotid stenting are conflicting.

Risks and benefits of antiplatelet therapy in uremic patients

Patients with renal insufficiency are at an increased risk for cardiovascular morbidity and mortality. Despite being at a substantial risk for thrombotic events, patients with renal insufficiency also experience a greater number of hemorrhagic complications associated with antiplatelet therapy than individuals with normal renal function. This review focuses on the benefits and risks of antiplatelet therapy in patients with impaired kidney function suffering from an acute coronary syndrome.