Benefits and safety of tirofiban among acute coronary syndrome patients with mild to moderate renal insufficiency: results from the Platelet Receptor Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Signs and Symptoms (PRISM-PLUS) trial

Effects of Tirofiban on Neurological Deterioration in Patients With Acute Ischemic Stroke: A Randomized Clinical Trial

Importance

Evidence supports using antiplatelet therapy in patients with acute ischemic stroke. However, neurological deterioration remains common under the currently recommended antiplatelet regimen, leading to poor clinical outcomes.

Objective

To determine whether intravenous tirofiban administered within 24 hours of stroke onset prevents early neurological deterioration in patients with acute noncardioembolic stroke compared with oral aspirin.

Design, Setting, and Participants

This investigator-initiated, multicenter, open-label, randomized clinical trial with blinded end-point assessment was conducted at 10 comprehensive stroke centers in China between September 2020 and March 2023. Eligible patients were aged 18 to 80 years with acute noncardioembolic stroke within 24 hours of onset and had a National Institutes of Health Stroke Scale (NIHSS) score of 4 to 20.

Intervention

Patients were assigned randomly (1:1) to receive intravenous tirofiban or oral aspirin for 72 hours using a central, web-based, computer-generated randomization schedule; all patients then received oral aspirin.

Main Outcome

The primary efficacy outcome was early neurological deterioration (increase in NIHSS score ≥4 points) within 72 hours after randomization. The primary safety outcome was symptomatic intracerebral hemorrhage within 72 hours after randomization.

Results

A total of 425 patients were included in the intravenous tirofiban (n = 213) or oral aspirin (n = 212) groups. Median (IQR) age was 64.0 years (56.0-71.0); 124 patients (29.2%) were female, and 301 (70.8%) were male. Early neurological deterioration occurred in 9 patients (4.2%) in the tirofiban group and 28 patients (13.2%) in the aspirin group (adjusted relative risk, 0.32; 95% CI, 0.16-0.65; P = .002). No patients in the tirofiban group experienced intracerebral hemorrhage. At 90-day follow-up, 3 patients (1.3%) in the tirofiban group and 3 (1.5%) in the aspirin group died (adjusted RR, 1.15; 95% CI, 0.27-8.54; P = .63), and the median (IQR) modified Rankin scale scores were 1.0 (0-1.25) and 1.0 (0-2), respectively (adjusted odds ratio, 1.28; 95% CI, 0.90-1.83; P = .17).

Conclusions and Relevance

In patients with noncardioembolic stroke who were seen within 24 hours of symptom onset, tirofiban decreased the risk of early neurological deterioration but did not increase the risk of symptomatic intracerebral hemorrhage or systematic bleeding.

Trial Registration

ClinicalTrials.gov Identifier: NCT04491695.

Effects of tirofiban on large vessel occlusion stroke are modified by etiology and renal function

OBJECTIVE

Renal function can modify the outcomes of large vessel occlusion (LVO) stroke across stroke etiologies in disparate degrees. The presence of renal function deficit can also impair the pharmacokinetics of tirofiban. Hence, this study aimed to investigate the roles of renal function in determining efficacy and safety of intravenous tirofiban before endovascular treatment (EVT) for acute ischemic stroke patients with large vessel occlusion (LVO).

METHODS

This study was a post hoc exploratory analysis of the RESCUE-BT trial. The primary outcome was the proportion of patients achieving functional independence (modified Rankin scale 0-2) at 90 days, and the primary safety outcome was the rate of symptomatic intracranial hemorrhage (sICH).

RESULTS

Among 908 individuals with available serum creatinine, decreased estimated glomerular filtration rate (eGFR) status was noted more commonly in patients with cardioembolic stroke (CE), while large artery atherosclerosis (LAA) was predominant in patients with normal renal function. In LAA with normal renal function, tirofiban was associated with higher rates of functional independence at 90 days (41.67% vs 59.80%, p = 0.003). However, for LVO patients with renal dysfunction, tirofiban did not improve functional outcomes for any of the etiologies (LAA, p = 0.876; CE, p = 0.662; others, p = 0.894) and significantly increased the risk of sICH among non-LAA patients (p = 0.020). Mediation analysis showed tirofiban reduced thrombectomy passes (12.27%) and drug/placebo to recanalization time (14.25%) mediated its effects on functional independence.

CONCLUSION

This present study demonstrated the importance of evaluating renal function before administering intravenous tirofiban among patients with LVO who are planned to undergo EVT.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet agents may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased. This is an update of a review first published in 2013.

OBJECTIVES

To evaluate the benefits and harms of antiplatelet agents in people with any form of CKD, including those with CKD not receiving renal replacement therapy, patients receiving any form of dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet agents versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Four authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data were pooled using the random-effects model. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 113 studies, enrolling 51,959 participants; 90 studies (40,597 CKD participants) compared an antiplatelet agent with placebo or no treatment, and 29 studies (11,805 CKD participants) directly compared one antiplatelet agent with another. Fifty-six new studies were added to this 2021 update. Seven studies originally excluded from the 2013 review were included, although they had a follow-up lower than two months. Random sequence generation and allocation concealment were at low risk of bias in 16 and 22 studies, respectively. Sixty-four studies reported low-risk methods for blinding of participants and investigators; outcome assessment was blinded in 41 studies. Forty-one studies were at low risk of attrition bias, 50 studies were at low risk of selective reporting bias, and 57 studies were at low risk of other potential sources of bias. Compared to placebo or no treatment, antiplatelet agents probably reduces myocardial infarction (18 studies, 15,289 participants: RR 0.88, 95% CI 0.79 to 0.99, I² = 0%; moderate certainty). Antiplatelet agents has uncertain effects on fatal or nonfatal stroke (12 studies, 10.382 participants: RR 1.01, 95% CI 0.64 to 1.59, I² = 37%; very low certainty) and may have little or no effect on death from any cause (35 studies, 18,241 participants: RR 0.94, 95 % CI 0.84 to 1.06, I² = 14%; low certainty). Antiplatelet therapy probably increases major bleeding in people with CKD and those treated with haemodialysis (HD) (29 studies, 16,194 participants: RR 1.35, 95% CI 1.10 to 1.65, I² = 12%; moderate certainty). In addition, antiplatelet therapy may increase minor bleeding in people with CKD and those treated with HD (21 studies, 13,218 participants: RR 1.55, 95% CI 1.27 to 1.90, I² = 58%; low certainty). Antiplatelet treatment may reduce early dialysis vascular access thrombosis (8 studies, 1525 participants) RR 0.52, 95% CI 0.38 to 0.70; low certainty). Antiplatelet agents may reduce doubling of serum creatinine in CKD (3 studies, 217 participants: RR 0.39, 95% CI 0.17 to 0.86, I² = 8%; low certainty). The treatment effects of antiplatelet agents on stroke, cardiovascular death, kidney failure, kidney transplant graft loss, transplant rejection, creatinine clearance, proteinuria, dialysis access failure, loss of primary unassisted patency, failure to attain suitability for dialysis, need of intervention and cardiovascular hospitalisation were uncertain. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, including prasugrel, ticagrelor, different doses of clopidogrel, abciximab, defibrotide, sarpogrelate and beraprost.

AUTHORS' CONCLUSIONS

Antiplatelet agents probably reduced myocardial infarction and increased major bleeding, but do not appear to reduce all-cause and cardiovascular death among people with CKD and those treated with dialysis. The treatment effects of antiplatelet agents compared with each other are uncertain.

Framing Cause-Effect Relationship of Acute Coronary Syndrome in Patients with Chronic Kidney Disease

The main causes of death in patients with chronic kidney disease (CKD) are of cardiovascular nature. The interaction between traditional cardiovascular risk factors (CVRF) and non-traditional risk factors (RF) triggers various complex pathophysiological mechanisms that will lead to accelerated atherosclerosis in the context of decreased renal function. In terms of mortality, CKD should be considered equivalent to ischemic coronary artery disease (CAD) and properly monitored. Vascular calcification, endothelial dysfunction, oxidative stress, anemia, and inflammatory syndrome represents the main uremic RF triggered by accumulation of the uremic toxins in CKD subjects. Proteinuria that appears due to kidney function decline may initiate an inflammatory status and alteration of the coagulation—fibrinolysis systems, favorizing acute coronary syndromes (ACS) occurrence. All these factors represent potential targets for future therapy that may improve CKD patient’s survival and prevention of CV events. Once installed, the CAD in CKD population is associated with negative outcome and increased mortality rate, that is the reason why discovering the complex pathophysiological connections between the two conditions and a proper control of the uremic RF are crucial and may represent the solutions for influencing the prognostic. Exclusion of CKD subjects from the important trials dealing with ACS and improper use of the therapeutical options because of the declined kidney functioned are issues that need to be surpassed. New ongoing trials with CKD subjects and platelets reactivity studies offers new perspectives for a better clinical approach and the expected results will clarify many aspects.

Platelet Function and Risk of Bleeding in Patients With Acute Coronary Syndrome Following Tirofiban Infusion

Aim: To assess platelet (PLT) function and bleeding risks in patients with acute coronary syndrome after tirofiban infusion.

Methods: Patients diagnosed with acute coronary syndrome from May 2016 to February 2018 in the Department of Cardiac Intensive Care Unit, Zhongshan Hospital, were enrolled. They were symmetrically allocated into two groups: tirofiban treatment group or control group (without tirofiban treatment). Blood samples were collected 24 h postoperation for the evaluation of antiplatelet effect of tirofiban. We applied thromboelastography to detect on-treatment PLT reactivity and conducted laboratory tests to assess the risk of bleeding following tirofiban treatment. After discharge, telephone follow-up and outpatient interview were carried out. The primary clinical endpoint was major adverse cardiovascular events, including cardiovascular death, cardiovascular mortality, myocardial infarction, and revascularization for the targeted vascular lesion.

Results: There were a total of 196 patients with acute coronary syndrome after screening with the inclusion criteria and the exclusion criteria. Ninety-eight patients were assigned to receive either tirofiban treatment or control treatment. Patients treated with tirofiban had more coronary lesions and stents implanted compared with the control group (P = 0.000). After tirofiban infusion, inhibition of platelet aggregation induced by thromboxane A₂ and adenosine diphosphate was significantly higher compared to patients without tirofiban infusion (80.3% ± 19.6% vs. 72.6% ± 13.0%, P = 0.002; and 81.0% ± 19.8% vs. 75.4% ± 12.4%, P = 0.020, respectively). There was no significant difference in the reduction of hemoglobin (Hb), hematocrit (Hct), and PLT after administration of tirofiban, compared with baseline (P > 0.05). In addition, no significant differences were identified between the two groups with respect to Hb, Hct, and PLT after tirofiban infusion. However, C-reactive protein level, referred to as an inflammation marker, was significantly lowered after infusion tirofiban compared with the control group (11.9 ± 14.2 vs. 17.9 ± 21.2, P = 0.020). During the 1-year follow-up, the incidence rate of major adverse cardiovascular events remains indiscriminate between the two groups (P = 0.208). The assessments of cardiac biomarkers showed that tirofiban could decrease incidence of procedural myocardial infarction (odds ratio [OR] = 0.250, 95% confidence interval [CI] = 0.067–0.925, P = 0.027). At follow-up, the morbidity of left atrial dilation in tirofiban-treated patients, defined as enlargement of left atrial diameter >40mm, was lower compared to the control group (OR = 0.533, 95% CI = 0.301–0.945, P = 0.031).

Conclusion: Tirofiban infusion could decrease PLT activation in patients with acute coronary syndrome without increasing the risk of bleeding. As a concomitant medication, tirofiban shows no benefit in reducing the occurrence of major adverse cardiovascular events.

Effect of antiplatelet therapy on cardiovascular and kidney outcomes in patients with chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

The benefits and risks of antiplatelet therapy for patients with chronic kidney disease (CKD) remain controversial. We undertook a systematic review and meta-analysis to investigate the effects of antiplatelet therapy on major clinical outcomes.

METHODS

We systematically searched MEDLINE, Embase, and the Cochrane Library for trials published before April 2019 without language restriction. We included rrandomized controlled trials that involved adults with CKD and compared antiplatelet agents with controls.

RESULTS

Fifty eligible trials that included at least one event were identified, providing data for 27773patients with CKD, including 4518 major cardiovascular events and 1962 all-cause deaths. Antiplatelet therapy produced a 15% (OR, 0.85; 95% CI 0.74-0.94) reduction in the odds of major cardiovascular events (P = 0.002), a 48% reduction for access failure events (OR, 0.52; 95% CI, 0.31-0.73), but had no significantly effect on all-cause death (OR, 0.87; 95% CI, 0.71-1.01) or kidney failure events (OR, 0.87; 95% CI, 0.32-1.55). Adverse events were significantly increased by antiplatelet therapy, including major (OR, 1.33; 95% CI, 1.11-1.59) or minor bleeding (OR, 1.66; 95% CI, 1.27-2.05). Among every 1000 persons with CKD treated with antiplatelet therapy for 12 months, 23 major cardiovascular events will be prevented while nine major bleeding events will occur.

CONCLUSIONS

Major prevention with antiplatelet agents (cardiovascular events and access failure), might outweigh the risk of bleeding, and there seemed to be an overall net benefit. Individual evaluation and careful monitoring are required.

Stent-Assisted Coil Embolization Using Only a Glycoprotein IIb/IIIa Inhibitor (Tirofiban) for Ruptured Wide-Necked Aneurysm Repair

OBJECTIVE

The aim of this study was to evaluate the safety and efficacy of stent-assisted coil embolization using only a glycoprotein IIb/IIIa inhibitor (tirofiban).

MATERIALS AND METHODS

We retrospectively reviewed patients with a subarachnoid hemorrhage due to ruptured wide-necked intracranial aneurysms who were treated by stent-assisted coil embolization. In all patients, the glycoprotein IIb/IIIa inhibitor tirofiban was administered just before stent deployment. Electronic medical records for these patients were reviewed for peri-procedural complications and extra-ventricular drainage catheter related hemorrhage, as well as Glasgow outcome scale (GOS) at discharge, 3 months, and 6 months follow-up were recorded.

RESULTS

Fifty-one aneurysms in 50 patients were treated. The mean patient age was 64.9 years. Eighteen patients (36%) received a World Federation of Neurosurgical Societies grade of 4 or 5. The mean aneurysm size was 9.48 mm and mean dome-to-neck ratio was 1.06. No intraoperative aneurysm ruptures occurred, although five (10%) episodes of asymptomatic stent thrombosis did occur. Three patients experienced a delayed thrombo-embolic event and two a delayed hemorrhagic event. Immediate radiologic assessment indicated a complete occlusion in 29 patients, a residual neck in 19, and a residual sac in 3. Four patients (8%) died. Sixteen patients (32%) experienced a poor GOS (< 4). Two aneurysms were recanalized during the follow-up period (mean, 19 months for clinical and 18 months for angiographic follow-up).

CONCLUSION

Treatment of ruptured wide-necked intracranial aneurysms via stent-assisted coil embolization with a glycoprotein IIb/IIIa inhibitor alone was found to be relatively safe and efficient.

Safety and preliminary efficacy of intravenous tirofiban in acute ischemic stroke patient without arterial occlusion on neurovascular imaging studies

BACKGROUND

There has been no effective treatment for acute ischemic stroke (AIS) patients who presented to the Emergency Department >4.5h without a visible arterial occlusion on the neurovascular imaging studies. In this study, we aimed to investigate whether intravenous antiplatelet agent tirofiban was safe and potentially effective in AIS patients who had no visible arterial occlusion and was outside of treatment window for Alteplase. The goal of this study was to collect preliminary data to plan a future phase II study.

METHOD

Twenty-five patients received intravenous tirofiban therapy. The safety outcomes were assessed by the incidence of symptomatic intracerebral hemorrhage (sICH), systematic bleeding and mortality. Efficacy outcomes were evaluated with National Institutes of Health Stroke Scale (NIHSS) score at day 7 (or discharge) and modified Rankin Scale (mRS) at 90days. Outcomes for these patients were compared with a historical age-gender-admission-NIHSS matched cohort treated with aspirin and/or clopidogrel.

RESULTS

The rate of intracerebral hemorrhage, systematic bleedings, and death were not found in both groups. At day 7 or discharge, the neurological function improved significantly in both treatment groups. However, the NIHSS score was lower in tirofiban group compared with the control group (2 vs.3, p=0.045). At 3months, more patients in tirofiban group had favorable outcomes (mRS 0-1) compared with control group (84% vs. 52%; adjusted odds ratio: 10.57; 95% CI: 1.54-72.33; p=0.016).

CONCLUSIONS

Intravenous tirofiban appears to be safe and potentially effective for the ischemic stroke patients with no artery occlusion on neurovascular imaging studies and being out of the window for thrombolytic therapy. A next logic step is to plan for a phase II study.

Renal function and outcomes in acute coronary syndrome: impact of clopidogrel

INTRODUCTION

Patients with renal dysfunction are more prone to bleeding when receiving antithrombotic drugs. The aim of the study was to assess the impact of clopidogrel on safety and efficacy in patients with renal dysfunction in non-ST elevation acute coronary syndromes.

METHODS AND RESULTS

Patients in the Clopidogrel in Unstable Angina to Prevent Recurrent Events (CURE) trial were analysed to assess the relationship of chronic kidney disease to cardiovascular outcomes. Renal function was estimated by the glomerular filtration rate computed from the baseline serum creatinine measurements in 12 253 (97.5%) patients enrolled in the trial. Patients were grouped into tertiles of glomerular filtration rate. The primary outcome (cardiovascular death, myocardial infarction, stroke combined) occurred more frequently in the lowest glomerular filtration rate tertile. The bleeding risk was also significantly increased in patients in this tertile, compared with the other two. The beneficial effect of adding clopidogrel to standard treatment in non-ST elevation acute coronary syndrome was observed in all three tertiles of renal function {(lower third relative risk (RR)=0.89 [95% confidence interval (CI) 0.76-1.05]; medium third RR=0.68 (95% CI 0.56-0.84); upper third RR=0.74 (95% CI 0.60-0.93) (P for heterogeneity=0.11)}. Clopidogrel treatment significantly increased the risk of minor bleeding in all tertiles of renal function. The risk of major or life-threatening bleeding increased moderately with the addition of clopidogrel to standard treatment [lower third RR=1.12 (95% CI 0.83-1.51); medium third RR=1.4 (95% CI 0.97-2.02); upper third RR=1.83 (95% CI 1.23-2.73)], but this did not appear to be greatest in those with the lowest renal function.

CONCLUSIONS

Even mild chronic kidney disease worsens the prognosis in patients with non-ST elevation acute coronary syndromes. Clopidogrel was beneficial and safe in patients with and without chronic kidney disease.

Randomly and Non-Randomly Missing Renal Function Data in the Strong Heart Study: A Comparison of Imputation Methods

Kidney and cardiovascular disease are widespread among populations with high prevalence of diabetes, such as American Indians participating in the Strong Heart Study (SHS). Studying these conditions simultaneously in longitudinal studies is challenging, because the morbidity and mortality associated with these diseases result in missing data, and these data are likely not missing at random. When such data are merely excluded, study findings may be compromised. In this article, a subset of 2264 participants with complete renal function data from Strong Heart Exams 1 (1989-1991), 2 (1993-1995), and 3 (1998-1999) was used to examine the performance of five methods used to impute missing data: listwise deletion, mean of serial measures, adjacent value, multiple imputation, and pattern-mixture. Three missing at random models and one non-missing at random model were used to compare the performance of the imputation techniques on randomly and non-randomly missing data. The pattern-mixture method was found to perform best for imputing renal function data that were not missing at random. Determining whether data are missing at random or not can help in choosing the imputation method that will provide the most accurate results.

Outcomes with prolonged clopidogrel therapy after coronary stenting in patients with chronic kidney disease

OBJECTIVES

Patients with chronic kidney disease (CKD) are at high risk of death or myocardial infarction (MI) after percutaneous coronary interventions (PCI). We assessed whether prolonged dual antiplatelet therapy beyond the recommended 12 months may prevent adverse outcomes in patients with CKD receiving drug-eluting stents (DES) or bare-metal stents (BMS).

METHODS

We studied all Veterans receiving PCI with BMS or first-generation DES in the Veterans Affairs (VA) Healthcare System between 2002 and 2006, classified by CKD (estimated glomerular filtration rate <60 mL/min) or normal renal function. We used landmark analyses from 12 months after PCI with Cox proportional hazards multivariable and propensity-adjusted models to assess the effect of prolonged clopidogrel (more than 12  months) versus 12 months or less after PCI on clinical outcomes from 1 year to 4 years after PCI.

RESULTS

Of 23 042 eligible subjects receiving PCI, 4880 (21%) had CKD. Compared with normal renal function, patients with CKD had higher risks of death or MI 1-4 years after DES (21% vs 12%, HR=1.75; 95% CI 1.51 to 2.04) or BMS (28% vs 15%, HR=2.10; 95% CI 1.90 to 2.32). In patients with CKD receiving DES, clopidogrel use of more than 12 months after PCI was associated with lower risks of death or MI (18% vs 24%, HR=0.74; 95% CI 0.58 to 0.95), and death (15% vs 23%, HR=0.61; 95% CI 0.47 to 0.80), but had no effect on repeat revascularisation 1-4 years after PCI.

CONCLUSIONS

In patients with CKD, prolonging clopidogrel beyond 12 months after PCI may decrease the risk of death or MI only in patients receiving first-generation DES. These results support a patient-tailored approach to prolonging clopidogrel after PCI.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet treatment may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased.

OBJECTIVES

To summarise the effects of antiplatelet treatment (antiplatelet agent versus control or other antiplatelet agent) for the prevention of cardiovascular and adverse kidney outcomes in individuals with CKD.

SEARCH METHODS

In January 2011 we searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and the Cochrane Renal Group's Specialised Register without language restriction.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet treatment versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data was pooled using the random-effects model.

MAIN RESULTS

We included 50 studies, enrolling 27,139 participants; 44 studies (21,460 participants) compared an antiplatelet agent with placebo or no treatment, and six studies (5679 participants) directly compared one antiplatelet agent with another. Compared to placebo or no treatment, antiplatelet agents reduced the risk of myocardial infarction (17 studies; RR 0.87, 95% CI 0.76 to 0.99), but not all-cause mortality (30 studies; RR 0.93, 95% CI 0.81 to 1.06), cardiovascular mortality (19 studies; RR 0.89, 95% CI 0.70 to 1.12) or stroke (11 studies; RR 1.00, 95% CI 0.58 to 1.72). Antiplatelet agents increased the risk of major (27 studies; RR 1.33, 95% CI 1.10 to 1.65) and minor bleeding (18 studies; RR 1.49, 95% CI 1.12 to 1.97). In terms of dialysis access outcomes, antiplatelet agents reduced access thrombosis or patency failure but had no effect on suitability for dialysis. Meta-regression analysis indicated no differences in the relative benefit or harms of treatment (risk of all-cause mortality, myocardial infarction, or major bleeding) by type of antiplatelet agent or stage of CKD. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, treatment in kidney transplant recipients, primary prevention, or risk of ESKD.

AUTHORS' CONCLUSIONS

Antiplatelet agents reduce myocardial infarction but increase major bleeding. Risks may outweigh harms among people with low annual risks of cardiovascular events, including those with early stages of CKD who do not have clinically-evident occlusive cardiovascular disease.

Managing cardiovascular risk in people with chronic kidney disease: a review of the evidence from randomized controlled trials

Cardiovascular disease is the leading cause of death and morbidity in people with chronic kidney disease (CKD) making measures to modify cardiovascular risk a clinical priority. The relationship between risk factors and cardiovascular outcomes is often substantially different in people with CKD compared with the general population, leading to uncertainty around pathophysiological mechanisms and the validity of generalizations from the general population. Furthermore, published reports of subgroup analyses from clinical trials have suggested that a range of interventions may have different effects in people with kidney disease compared with those with normal kidney function. There is a relative scarcity of randomized controlled trials (RCTs) conducted in CKD populations, and most such trials are small and underpowered. As a result, evidence to support cardiovascular risk modification measures for people with CKD is largely derived from small trials and post hoc analyses of RCTs conducted in the general population. In this review, we examine the available RCT evidence on interventions aimed at preventing cardiovascular events in people with kidney disease to identify beneficial treatments as well as current gaps in knowledge that should be a priority for future research.

Chronic kidney disease in acute coronary syndromes

Chronic kidney disease (CKD) is associated with a high burden of coronary artery disease. In patients with acute coronary syndromes (ACS), CKD is highly prevalent and associated with poor short- and long-term outcomes. Management of patients with CKD presenting with ACS is more complex than in the general population because of the lack of well-designed randomized trials assessing therapeutic strategies in such patients. The almost uniform exclusion of patients with CKD from randomized studies evaluating new targeted therapies for ACS, coupled with concerns about further deterioration of renal function and therapy-related toxic effects, may explain the less frequent use of proven medical therapies in this subgroup of high-risk patients. However, these patients potentially have much to gain from conventional revascularization strategies used in the general population. The objective of this review is to summarize the current evidence regarding the epidemiology and the clinical and prognostic relevance of CKD in ACS patients, in particular with respect to unresolved issues and uncertainties regarding recommended medical therapies and coronary revascularization strategies.

Antiplatelet drugs: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

The article describes the mechanisms of action, pharmacokinetics, and pharmacodynamics of aspirin, dipyridamole, cilostazol, the thienopyridines, and the glycoprotein IIb/IIIa antagonists. The relationships among dose, efficacy, and safety are discussed along with a mechanistic overview of results of randomized clinical trials. The article does not provide specific management recommendations but highlights important practical aspects of antiplatelet therapy, including optimal dosing, the variable balance between benefits and risks when antiplatelet therapies are used alone or in combination with other antiplatelet drugs in different clinical settings, and the implications of persistently high platelet reactivity despite such treatment.

Beneficial effects of intracoronary tirofiban bolus administration following upstream intravenous treatment in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention: the ICT-AMI study

BACKGROUND

We investigated whether an additional intracoronary tirofiban bolus administration following upstream intravenous treatment could further improve myocardial reperfusion and clinical outcome in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

METHODS

A total of 453 eligible STEMI patients were randomly allocated to intracoronary bolus administration of tirofiban (10 μg/kg; n=229) or saline (10 mL; n=224) during primary PCI, followed by intravenous tirofiban infusion (0.15 μg/kg/min) for 24-36 h. Serum levels of P-selectin, vWF, CD40L and serum amyloid A (SAA) in the coronary sinus were measured before and after intracoronary bolus administration. The primary endpoint was ST-segment resolution (STR) at 90 min after the procedure. Second endpoints included corrected TIMI frame count (cTFC), left ventricular volumes and ejection fraction (EF), and major adverse cardiac events (MACE) at 30-day and 6-month follow-up.

RESULTS

Intracoronary tirofiban administration resulted in a higher rate of completed STR (59.0% vs. 44.6%, P=0.002), lower cTFC (21.6±5.4 vs. 23.7±7.8, P=0.048), and significantly reduced coronary sinus levels of P-selectin, vWF, CD40L and SAA. Patients treated with intracoronary tirofiban had a trend toward less MACE at 30 days (3.1% vs. 6.7%, P=0.072). At 6 months, left ventricular end-systolic volume was smaller, EF was higher and MACE-free survival was improved (96.1% vs. 90.6%, P=0.020) in the intracoronary tirofiban group.

CONCLUSIONS

An additional intracoronary tirofiban bolus administration following upstream intravenous treatment reduces coronary circulatory platelet activation and inflammatory process, and significantly improves myocardial reperfusion and left ventricular function as well as 6-month MACE-free survival for STEMI patients undergoing primary PCI.

Association of cystatin C with ischemia in patients with coronary heart disease

BACKGROUND

Elevated concentrations of cystatin C are associated with greater cardiovascular morbidity and mortality. We sought to determine whether elevated concentrations of cystatin C were associated with inducible ischemia in patients with coronary heart disease (CHD).

METHODS

We measured serum cystatin C and performed exercise treadmill testing with stress echocardiography in a cross-sectional study of 899 outpatients with CHD.

RESULTS

Among the 241 participants in the highest quartile of cystatin C (>1.30 mg/L), 38% had inducible ischemia, compared with 13% of those in the lowest quartile of cystatin C < 0.92 mg/L; adjusted odds ratio [OR]: 2.1; 95% confidence interval [CI]: 1.2 to 3.8; p = 0.01). However, this association differed in participants with and without a history of coronary artery bypass graft (CABG), as well as in users and nonusers of beta-blockers and statins (p values for interaction < 0.1). Among participants without a history of CABG, 35% of those in the highest quartile and 9% of those in the lowest quartile of cystatin C had inducible ischemia (adjusted OR: 3.05; 95% CI: 1.3-6.9; p = 0.008). Among participants who were not using beta-blockers, 44% of those in the highest quartile and 7% in the lowest quartile of cystatin C had inducible ischemia (adjusted OR: 5.3; 95% CI: 1.8-15.5; p = 0.002). Among participants who were not using statins, 39% of participants in the highest quartile and 4% of those in the lowest quartile had inducible ischemia (adjusted OR: 10.3; 95% CI: 2.5-43.3; p = 0.001).

CONCLUSIONS

Elevated levels of cystatin C are independently associated with inducible ischemia among outpatients with stable coronary disease.

Antiplatelet therapies: drug interactions in the management of vascular disorders

Antiplatelet drugs represent a key class of drugs that are of proven value in arterial thromboembolic disorders. There is a need for effective, safe antiplatelet agents or their combinations to provide predictable therapeutic benefit, dosage flexibility, and unique pharmacologic profiles, such as rapid onset in acute thrombotic states, as well as sustained antiplatelet effects in chronic platelet-activating states (e.g., post-stent placement). Aspirin, clopidogrel, or their combination have shown improved clinical outcomes in certain unique settings, and the search for additional antiplatelet agents is ongoing. Current studies suggest that combination antiplatelet therapy with existing agents is best considered a use-adapted strategy, with the greatest clinical benefit of combination therapy realized in acute, platelet-activating, and prothrombotic states.

Impact of chronic kidney disease on early (30-day) and late (1-year) outcomes of patients with acute coronary syndromes treated with alternative antithrombotic treatment strategies: an ACUITY (Acute Catheterization and Urgent Intervention Triage strategY) substudy

OBJECTIVES

In this substudy of the ACUITY (Acute Catheterization and Urgent Intervention Triage strategY) trial, we investigated the relationship between chronic kidney disease (CKD) and clinical outcomes, and compared the safety and efficacy of bivalirudin monotherapy versus heparin plus a glycoprotein IIb/IIIa inhibitor (GPI).

BACKGROUND

CKD is an important predictor of prognosis in the general population. The outcomes of patients with CKD and acute coronary syndromes (ACS) have not been well studied.

METHODS

In the ACUITY study, 13,819 patients with moderate- and high-risk ACS undergoing an early, invasive strategy were randomly assigned to 1 of 3 antithrombin regimens: a heparin plus a GPI, bivalirudin plus a GPI, or bivalirudin monotherapy. CKD (creatinine clearance <60 ml/min) was present in 2,469 (19.1%) of 12,939 randomized patients with baseline creatinine clearance data.

RESULTS

Patients with CKD had worse 30-day and 1-year clinical outcomes than those with normal renal function. There were no significant differences between bivalirudin monotherapy and heparin plus a GPI in rates of 30-day composite ischemia (11.1% vs. 9.4%, p = 0.27) and net clinical adverse outcomes (16.1% vs. 16.9%, p = 0.65). There was remarkably less major bleeding (6.2% vs. 9.8%, p = 0.008) at 30 days, but no significant difference in 1-year composite ischemia (22.0% vs. 18.9%, p = 0.10) or mortality (7.1% vs. 7.3%, p = 0.96).

CONCLUSIONS

In patients with ACS, CKD is associated with higher 30-day and 1-year adverse event rates. Compared with heparin plus a GPI, the use of bivalirudin monotherapy in patients with CKD results in nonstatistically different ischemic outcomes, but significantly less 30-day major bleeding.

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.

Folic Acid-Based Intervention in Non-ST Elevation Acute Coronary Syndromes

Homocysteinemia is a risk factor for cardiovascular diseases. Folic acid combined with vitamins B6 and B12 is effective in lowering homocysteine levels. This randomized placebo-controlled study was designed to determine the effect of a folic acid-based supplement on secondary prevention of clinical events in non-ST-segment elevation acute coronary syndromes. The study comprised 240 patients with either unstable angina or non-ST-elevation myocardial infarction in the previous 2 weeks who were randomized to a folate group ( n = 116) or a placebo group ( n = 124). The folate group received 1 mg folic acid, 400 μg vitamin B12, and 10 mg vitamin B6 daily. Clinical outcomes within 6 months were assessed. The composite endpoint of death, nonfatal acute coronary syndrome, and serious re-hospitalization was significantly higher in the folate group; serious re-hospitalization alone was significantly higher in this group. Advanced age and diabetes increased susceptibility to the composite outcome. Folic acid-based supplementation is not beneficial and may even be harmful in the secondary prevention of cardiovascular events in patients with unstable angina and non-ST-elevation myocardial infarction. Further studies on the safety of such supplements are suggested. Controlled Clinical Trials Registry no. ISRCTN30249553.

Use of Low Molecular Weight Heparins and Glycoprotein IIb/IIIa Inhibitors in Patients with Chronic Kidney Disease

Despite aggressive intervention, cardiac causes of death, including acute coronary syndrome (ACS), continue to be a major source of mortality in patients with chronic kidney disease (CKD), including end-stage renal disease (ESRD). Multiple large prospective trials have demonstrated the clinical benefits of both low molecular weight heparin (LMWH) and glycoprotein (Gp) IIb/IIIa inhibitors in treating patients with ACS. Unfortunately patients with significant impairment of kidney function have generally been excluded from these major clinical trials. Consequently relatively little is known about the pharmacokinetics, appropriate dosing, efficacy, and safety of these medications in patients with CKD of various stages. This article examines the available literature regarding the pharmacokinetics, dosing, efficacy, and safety of LMWH and Gp IIb/IIIa inhibitors in patients with CKD.

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.

Antiplatelet drugs: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)

This article about currently available antiplatelet drugs is part of the Antithrombotic and Thrombolytic Therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). It describes the mechanism of action, pharmacokinetics, and pharmacodynamics of aspirin, reversible cyclooxygenase inhibitors, thienopyridines, and integrin alphaIIbbeta3 receptor antagonists. The relationships among dose, efficacy, and safety are thoroughly discussed, with a mechanistic overview of randomized clinical trials. The article does not provide specific management recommendations; however, it does highlight important practical aspects related to antiplatelet therapy, including the optimal dose of aspirin, the variable balance of benefits and hazards in different clinical settings, and the issue of interindividual variability in response to antiplatelet drugs.

Management of ischemic heart disease in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) and ischemic heart disease (IHD) have strikingly high mortality rates. In the general population, there has been a reduction in the mortality and morbidity rates for IHD through the implementation of effective risk-factor-reduction programs and better interventions for patients with established IHD. No such trend has been observed in patients with end-stage kidney disease. This review article addresses the following topics: (i) epidemiology, pathogenesis, clinical CKD patients with IHD; (ii) diagnostic modalities for IHD and their limitation in CKD patients; (iii) medical treatment options and revascularization strategies for these high-risk patients; and (iv) optimal cardiovascular risk management. Generally, in CKD patients with IHD an aggressive approach to IHD is warranted, a low threshold for diagnostic testing should be employed, and awaiting a clinical trial targeting these patients they should be considered for all proven strategies to improve outcomes.

Evaluation of ischaemia-modified albumin as a marker of myocardial ischaemia in end-stage renal disease

The early diagnosis of myocardial ischaemia is problematic in patients with ESRD (end-stage renal disease). The aim of the present study was to determine whether IMA (ischaemia-modified albumin) increases during dobutamine stress and detects myocardial ischaemia in patients with ESRD. A total of 114 renal transplant candidates were studied prospectively, and all received DSE (dobutamine stress echocardiography). IMA levels were taken at baseline and 1 h after cessation of DSE. A total of 35 patients (31%) had a positive DSE result. Baseline IMA levels were not significantly different in the DSE-positive and -negative groups. The increase in IMA was significantly higher in the DSE-positive group compared with those with no ischaemic response (26.5±19.1 compared with 8.2±9.6 kU/l respectively; P=0.007; where kU is kilo-units). From ROC (receiver operator charactertistic) curve analysis, the optimal IMA increase to predict an ischaemic response was 20 kU/l, with a sensitivity of 81% and a specificity of 72% [area under the curve, 0.80 (95% confidence interval, 0.44–0.94); P=0.03]. There were 18 deaths, ten of which were cardiac in nature over a follow up period of 2.25±0.71 years. An increase in IMA ≥20 kU/l was associated with significantly worse survival (P=0.02). In conclusion, IMA is a moderately accurate marker of myocardial ischaemia in ESRD. Patients with an increase in IMA ≥20 kU/l during DSE had significantly worse survival.

Kidney Disease and Cardiovascular Risk

Kidney failure and chronic kidney disease (CKD) are associated with accelerated cardiovascular disease, apparently because of a high burden of traditional vascular risk factors and possibly nontraditional risk factors such as inflammation, chronic volume overload, and abnormal calcium-phosphate metabolism. Although the burden of cardiovascular disease in CKD patients is well documented, potentially beneficial therapies appear to be underused in mild to moderate CKD and are relatively understudied in those with kidney failure. This review describes the epidemiology and pathophysiology of cardiovascular disease in CKD. We also discuss the clinical and public health implications of current knowledge and outline opportunities for further research.

Assessing the impact of different imputation methods on serial measures of renal function: the Strong Heart Study

Missing data are a common problem in epidemiologic studies. This study had two aims: (a) to determine which method for imputing missing renal function data provides estimates closest to those made with complete data and (b) to determine which measure of renal function better estimates cardiovascular disease (CVD) risk. For these analyses, a subset of Strong Heart Study participants with complete data for renal function was identified. Data were randomly dropped from this complete set at three rates: 30, 45, and 60%. Five common techniques for handling missing data were compared: imputation using the mean, adjacent value (AV), single imputation, multiple imputation, and listwise deletion. Differences between the imputed sets and the complete set were determined for each method. Imputation methods were used to fill in missing values for serum creatinine (Scr) in one model and estimated glomerular filtration rate (eGFR) in another. For both Scr and eGFR, the AV method provided the most favorable results in predicting CVD risk, regardless of the rate of missing data.

Biomarkers in acute cardiac disease: the present and the future

The use of biomarkers to aid diagnosis and treatment is increasing rapidly as genomics and proteomics help us expand the number of markers we can use and as an improved understanding of the pathophysiology of cardiac disease guides their use. However, as with all rapidly expanding fields, there is the risk of excessive enthusiasm unless we are circumspect about the data that guide the clinical use of these new tools. This review focuses first on how to use troponin, which at present is the best validated of the new markers, and will hopefully provide insight into how to use this biomarker more productively by distinguishing subsets of patients and by providing an understanding of the meaning of elevations in various clinical situations. The review then discusses the use as well as the knowledge gaps associated with emerging biomarkers such as B-type natriuretic peptide and C-reactive protein, which are increasingly moving toward more productive clinical use. Finally, it reflects on some of the large number of markers that are still in development.

Percutaneous Coronary Intervention in Patients with End-Stage Renal Disease

Patients with end-stage renal disease (ESRD) represent a growing number of patients in the cardiac catheterization laboratories worldwide. This is a consequence of the growing absolute number of ESRD patients in developed countries, better noninvasive diagnostic tools, better catheterization facilities and last-but-not-least better education of referring physicians about the incidence and prognosis of coronary artery disease (CAD) for patients with ESRD. There is growing evidence of the positive impact of coronary revascularization on long-term outcome of these patients. ESRD patients have a high comorbidity and are therefore better candidates for the less invasive approach using percutaneous coronary intervention (PCI) rather than coronary artery bypass surgery (CABG). From the view of the interventional cardiologist, ESRD patients represent one of the most challenging patient cohort concerning technical challenges and potential risk of complication for the patient. Percutaneous coronary intervention (PCI) including debulking techniques and stent implantation is the current standard therapy for patients with symptomatic single-vessel disease (SVD) and the preferred therapy for most patients with focal, polyfocal or even diffuse multi-vessel disease (MVD). Coronary bypass surgery is reserved for a decreasing number of patients with mechanically untreatable coronary lesions and unprotected left main stem stenosis. The problem of restenosis and subsequent target lesion revascularization has been decreased to a minimum by the use of drug-eluting stents (DES), even though prospective randomized trials including ESRD patients are lacking. In case of acute coronary syndromes, the need for immediate coronary angiography and subsequent revascularization by means of PCI should be pointed out.

Morbidity, mortality and economic burden of renal impairment in cardiac intensive care

BACKGROUND

Moderate to severe impairment of renal function has emerged as a potent risk factor for adverse short- and long-term outcomes among patients presenting with cardiac disease.

AIMS

We sought to define the clinical, late mortality and economic burden of this risk factor among patients presenting to cardiac intensive care.

METHODS

A clinical audit of patients presenting to cardiac intensive care was undertaken between July 2002 and June 2003. All patients presenting with cardiac diagnoses were included in the study. Baseline creatinine levels were assessed in all patients. Late mortality was assessed by the interrogation of the National Death Register. Renal impairment was defined as estimated glomerular filtration rate <60 mL/min per 1.73 m2, as calculated by the Modified Diet in Renal Disease formula. In-hospital and late outcomes were compared by Cox proportional hazards modelling, adjusting for known confounders. A matched analysis and attributable risk calculation were undertaken to assess the proportion of late mortality accounted for by impairment of renal function and other known negative prognostic factors. The in-hospital total cost associated with renal impairment was assessed by linear regression.

RESULTS

Glomerular filtration rate <60 mL/min per 1.73 m2 was evident in 33.0% of this population. Among these patients, in-hospital and late mortality were substantially increased: risk ratio 13.2; 95% CI 3.0-58.1; P < 0.001 and hazard ratio 6.2; 95% CI 3.6-10.7; P < 0.001, respectively. In matched analysis, renal impairment to this level was associated with 42.1% of all the late deaths observed. Paradoxically, patients with renal impairment were more conservatively managed, but their hospitalizations were associated with an excess adjusted in-hospital cost of $A1676.

CONCLUSION

Impaired renal function is associated with a striking clinical and economic burden among patients presenting to cardiac intensive care. As a marker for future risk, renal function accounts for a substantial proportion of the burden of late mortality. The burden of risk suggests a greater potential opportunity for improvement of outcomes through optimisation of therapeutic strategies.

Chronic kidney disease in patients with non-ST-segment elevation acute coronary syndromes

PURPOSE

Chronic kidney disease has been linked to high mortality rates in patients with ST-segment elevation myocardial infarction but has not been well described for patients with non-ST-segment elevation acute coronary syndromes. We examined the treatment and outcomes of patients with both non-ST-segment elevation acute coronary syndromes and moderate to severe chronic kidney disease.

SUBJECTS AND METHODS

We evaluated 45343 patients with non-ST-segment elevation acute coronary syndromes enrolled in the CRUSADE Quality Improvement Initiative and compared treatments and outcomes in patients with and without moderate to severe chronic kidney disease.

RESULTS

Patients presenting with moderate to severe chronic kidney disease (n = 6560) were older, more often diabetic, and more likely to present with signs of congestive heart failure. Adherence to Class IA/IB guidelines recommendations was lower in patients with moderate to severe chronic kidney disease, who were significantly less likely to be treated with medications, undergo invasive cardiac procedures, and be given discharge counseling. Moderate to severe chronic kidney disease was associated with a 50% increased risk of mortality and a 70% increased likelihood of transfusion. Despite having a higher risk of adverse outcomes, patients with moderate to severe chronic kidney disease were treated less aggressively than patients with normal renal function.

CONCLUSIONS

These findings suggest that, in patients with moderate to severe chronic kidney disease, safety concerns about adverse outcomes and the absence of trial data for this population may limit the use of guidelines-recommended therapies and interventions for non-ST-segment elevation acute coronary syndromes. The decreased use of discharge counseling in patients with moderate to severe chronic kidney disease and non-ST-segment elevation acute coronary syndromes may represent therapeutic nihilism.

Coronary artery disease and peripheral vascular disease in chronic kidney disease: an epidemiological perspective

The enormous burden of CAD and PVD inpatients who have CKD contributes substantially to increased morbidity and mortality. The increased risk of vascular disease observed in CKD patients is likely to be multifactorial, with contributions from traditional and nontraditional cardiovascular factors. Given the overwhelming evidence on the known benefits of cardioprotective medications, their underuse remains puzzling in a population at enormous risk. During the past 5 years, the research community and national interest groups have made significant progress in organizing a concerted approach to improve the management of patients who have CKD and vascular disease. Much work remains to be done. The development of national guidelines in the management of these patients at high risk for future cardiovascular events will be a welcome step. The evaluation of multitargeted interventions for reduction of cardiovascular risk through randomized clinical trials is desperately needed. Finally, the low use of known cardioprotective strategies in this high-risk group is a serious issue and warrants immediate attention at local and national levels.

Treatment of acute coronary syndromes in patients who have chronic kidney disease

Patients with CKD and CAD have traditionally been a difficult population to diagnose and treat in the setting of ACS. In addition to having poorer outcomes post-ACS, data are lacking regarding best treatments available. Aggressive interventional and medical treatments in this group with already poor outcomes are not necessarily contraindicated and should always be considered. The appalling outcome for CKD patients post-ACS is improved by many therapies shown to benefit in the non-CKD patients. Data suggest that troponins are useful markers in CKD patients, that major bleeding is not increased with the use of GP IIb-IIIa antagonists, that thrombolytics have been used successfully in CKD patients, and that PCI electively and as a primary treatment for ACS is successful and probably more beneficial to treatment.

Epidemiology and risk factors for chronic kidney disease

Kidney disease is highly prevalent in the United States population and groups at high risk for increased prevalence of CKD include individuals with a family history of ESRD, diabetes, hypertension, and cardiovascular disease. Despite the increased risk of ESRD observed for blacks compared with whites, racial disparities in the prevalence of kidney disease have not been consistently demonstrated in the United States population. Although the reasons for discrepancy in risk of ESRD and CKD have not been established, clinicians should be aware that more rapid progression of CKD among blacks is a possible explanation for this observation and that closer monitoring and intensive care of risk factors associated with progressive renal injury is warranted for blacks with CKD and in other high-risk groups. Therapeutic interventions that delay or prevent progressive kidney disease are well established and incorporated into widely disseminated clinical practice guidelines. These interventions include aggressive blood pressure control with agents that block the renin-angiotensin system, reduction of dietary protein to recommended levels for the American diet, weight loss, smoking cessation, and control of hyperlipidemia. These interventions also reduce the risk of cardiovascular disease and should be regarded as essential components of care of CKD. Achieving high levels of medically appropriate care of CKD patients and reduction in risk of progression to ESRD may be delayed by barriers created by individual and regional poverty.

Chronic kidney disease as cause of cardiovascular morbidity and mortality

To make an evidence-based evaluation of the relationship between kidney failure and cardiovascular risk, we reviewed the literature obtained from a PubMed search using pre-defined keywords related to both conditions and covering 18 years (1986 until end 2003). Eighty-five publications, covering 552 258 subjects, are summarized. All but three studies support a link between kidney dysfunction and cardiovascular risk. More importantly, the association is observed very early during the evolution of renal failure: an accelerated cardiovascular risk appears at varying glomerular filtration rate (GFR) cut-off values, which were >/=60 ml/min in at least 20 studies. Many studies lacked a clear definition of cardiovascular disease and/or used a single determination of serum creatinine or GFR as an index of kidney function, which is not necessarily corresponding to well-defined chronic kidney disease. In six studies, however, chronic kidney dysfunction and cardiovascular disease were well defined and the results of these confirm the impact of kidney dysfunction. It is concluded that there is an undeniable link between kidney dysfunction and cardiovascular risk and that the presence of even subtle kidney dysfunction should be considered as one of the conditions necessitating intensive prevention of this cardiovascular risk.

Analysis of bleeding complications associated with glycoprotein IIb/IIIa receptors blockade in patients with high-risk acute coronary syndromes: Insights from the PRISM-PLUS study

We aim to characterize the hemorrhagic complications and predictors of increased bleeding risk in a population of patients with high-risk acute coronary syndromes (ACS), enrolled in the PRISM-PLUS study. Patients treated with heparin plus tirofiban had more bleeding events compared to patients treated with heparin alone. No significant increase in major bleeding, thrombocytopenia, blood loss and blood products transfusions was observed among the patients who received the combination therapy. Several clinical variables were independently associated with increased risk of bleeding for both treatment groups: advanced age, lower body weight, female gender, decreased creatinine clearance (<30 ml/min). Females, patients with impaired renal function, patients requiring percutaneous coronary intervention (PCI), especially prolonged PCI (>100 min duration) or coronary artery bypass surgery (CABG) were at risk for increased major bleeding complications. Increased blood loss was also found in females, patients with elevated diastolic blood pressure, PCI, duration of PCI>100 min or CABG. No incremental risk was detected with the addition of tirofiban to heparin in patients at risk for major bleeding or increased blood loss. We concluded that identification of patients with high-risk ACS, at risk for bleeding complications and blood loss can be done with specific clinical variables. Tirofiban added to heparin increased minor hemorrhagic complications. Although there was no significant increase in major bleeding, thrombocytopenia and blood transfusions with the combination of tirofiban plus heparin, the power to detect a statistically significant difference in these endpoints was limited by the small number of events.

Cardiovascular risk in chronic kidney disease

National Kidney Foundation guidelines define chronic kidney disease (CKD) as persistent kidney damage (confirmed by renal biopsy or markers of kidney damage) and/or glomerular filtration rate (GFR) <60 mL/min/1.73m2 for greater than three months. Patients with CKD experience higher mortality and adverse cardiovascular (CV) event rates, which remains significant after adjustment for conventional coronary risk factors. This progressive CV risk associated with worsening renal function may be explained by other factors that become increasingly important with renal decline. In this regard, more investigation of nonconventional factors that have received a lot of attention includes associations with inflammation, albuminuria, reduced vascular compliance, and homocysteine. In addition, individuals with CKD encounter the problem of "therapeutic nihilism," in which there is a lack of appropriate risk factor modification and intervention, despite established awareness of their high cardiovascular risk. Several studies suggest that these individuals derive as much, if not more, benefit from evidence-based cardiovascular therapies and strategies. Greater educational efforts are needed to reduce this therapeutic gap.

Prognostic significance of renal insufficiency in patients presenting with acute coronary syndrome (the Prospective Multicenter SYCOMORE study)

This prospective, multicenter, observational study was designed to assess the in-hospital prognostic importance of renal insufficiency among patients presenting with acute coronary syndrome (ACS). One third of patients with ACS presented with renal insufficiency. After adjustment for potential confounders, decreasing renal function was independently associated with in-hospital death, bleeding, and contrast-induced nephropathy.