Coronary stent thrombosis in patients with chronic renal insufficiency

Ticagrelor or Clopidogrel as Antiplatelet Agents in Patients with Chronic Kidney Disease and Cardiovascular Disease: A Meta-analysis

INTRODUCTION

The worldwide prevalence of chronic kidney disease (CKD) has significantly increased in the past decades. Scientific reports have shown CKD to be an enhancing risk factor for the development of cardiovascular disease (CVD), which is the leading cause of premature death in patients with CKD. Clinical practice guidelines are ambiguous in view of the use of antiplatelet drugs in patients with CKD because patients with moderate-to-severe CKD were often excluded from clinical trials evaluating the efficacy and safety of anticoagulants and antiplatelet agents. In this analysis, we aimed to systematically assess the adverse cardiovascular and bleeding outcomes that were observed with ticagrelor versus clopidogrel use in patients with CKD and cardiovascular disease.

METHODS

Electronic databases including Web of Science, Google Scholar, http://www.

CLINICALTRIALS

gov , Cochrane database, EMBASE, and MEDLINE were carefully searched for English-based articles comparing ticagrelor with clopidogrel in patients with CKD. Adverse cardiovascular outcomes and bleeding events were the endpoints in this study. The latest version of the RevMan software (version 5.4) was used to analyze the data. Risk ratios (RR) with 95% confidence intervals (CI) were used to represent the data post analysis.

RESULTS

A total of 15,664 participants were included in this analysis, whereby 2456 CKD participants were assigned to ticagrelor and 13,208 CKD participants were assigned to clopidogrel. Our current analysis showed that major adverse cardiac events (MACEs) (RR: 0.85, 95% CI: 0.71-1.03; P = 0.09), all-cause mortality (RR: 0.82, 95% CI: 0.57- 1.18; P = 0.29), cardiovascular death (RR: 0.83, 95% CI: 0.56-1.23; P = 0.35), myocardial infarction (RR: 0.87, 95% CI: 0.70-1.07; P = 0.19), ischemic stroke (RR: 0.80, 95% CI: 0.58-1.11; P = 0.18), and hemorrhagic stroke (RR: 1.06, 95% CI: 0.38-2.99; P = 0.91) were not significantly different in CKD patients who were treated with ticagrelor versus clopidogrel. Thrombolysis in myocardial infarction (TIMI)-defined minor (RR: 0.89, 95% CI: 0.52-1.53; P = 0.68) and TIMI major bleeding (RR: 1.10, 95% CI: 0.69-1.76; P = 0.67) were also not significantly different. However, bleeding defined according to the academic research consortium (BARC) bleeding type 1 or 2 (RR: 1.95, 95% CI: 1.13-3.37; P = 0.02) and BARC bleeding type 3 or 5 (RR: 1.70, 95% CI: 1.17-2.48; P = 0.006) were significantly higher with ticagrelor.

CONCLUSIONS

When compared with clopidogrel, even though ticagrelor was not associated with higher risk of adverse cardiovascular outcomes in these patients with CKD, it was associated with significantly higher BARC bleeding. Therefore, the safety outcomes of ticagrelor still require further evaluation in patients with CKD. Nevertheless, this hypothesis should only be confirmed with more powerful results that could usually only be achieved using large-scale randomized trials.

The prognostic utility of tests of platelet function for the detection of 'aspirin resistance' in patients with established cardiovascular or cerebrovascular disease: a systematic review and economic evaluation

BACKGROUND

The use of aspirin is well established for secondary prevention of cardiovascular disease. However, a proportion of patients suffer repeat cardiovascular events despite being prescribed aspirin treatment. It is uncertain whether or not this is due to an inherent inability of aspirin to sufficiently modify platelet activity. This report aims to investigate whether or not insufficient platelet function inhibition by aspirin ('aspirin resistance'), as defined using platelet function tests (PFTs), is linked to the occurrence of adverse clinical outcomes, and further, whether or not patients at risk of future adverse clinical events can be identified through PFTs.

OBJECTIVES

To review systematically the clinical effectiveness and cost-effectiveness evidence regarding the association between PFT designation of 'aspirin resistance' and the risk of adverse clinical outcome(s) in patients prescribed aspirin therapy. To undertake exploratory model-based cost-effectiveness analysis on the use of PFTs.

DATA SOURCES

Bibliographic databases (e.g. MEDLINE from inception and EMBASE from 1980), conference proceedings and ongoing trial registries up to April 2012.

METHODS

Standard systematic review methods were used for identifying clinical and cost studies. A risk-of-bias assessment tool was adapted from checklists for prognostic and diagnostic studies. (Un)adjusted odds and hazard ratios for the association between 'aspirin resistance', for different PFTs, and clinical outcomes are presented; however, heterogeneity between studies precluded pooling of results. A speculative economic model of a PFT and change of therapy strategy was developed.

RESULTS

One hundred and eight relevant studies using a variety of PFTs, 58 in patients on aspirin monotherapy, were analysed in detail. Results indicated that some PFTs may have some prognostic utility, i.e. a trend for more clinical events to be associated with groups classified as 'aspirin resistant'. Methodological and clinical heterogeneity prevented a quantitative summary of prognostic effect. Study-level effect sizes were generally small and absolute outcome risk was not substantially different between 'aspirin resistant' and 'aspirin sensitive' designations. No studies on the cost-effectiveness of PFTs for 'aspirin resistance' were identified. Based on assumptions of PFTs being able to accurately identify patients at high risk of clinical events and such patients benefiting from treatment modification, the economic model found that a test-treat strategy was likely to be cost-effective. However, neither assumption is currently evidence based.

LIMITATIONS

Poor or incomplete reporting of studies suggests a potentially large volume of inaccessible data. Analyses were confined to studies on patients prescribed aspirin as sole antiplatelet therapy at the time of PFT. Clinical and methodological heterogeneity across studies precluded meta-analysis. Given the lack of robust data the economic modelling was speculative.

CONCLUSIONS

Although evidence indicates that some PFTs may have some prognostic value, methodological and clinical heterogeneity between studies and different approaches to analyses create confusion and inconsistency in prognostic results, and prevented a quantitative summary of their prognostic effect. Protocol-driven and adequately powered primary studies are needed, using standardised methods of measurements to evaluate the prognostic ability of each test in the same population(s), and ideally presenting individual patient data. For any PFT to inform individual risk prediction, it will likely need to be considered in combination with other prognostic factors, within a prognostic model.

STUDY REGISTRATION

This study is registered as PROSPERO 2012:CRD42012002151.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

In-hospital major clinical outcomes in patients with chronic renal insufficiency presenting with acute coronary syndrome: data from a Registry of 8176 patients

OBJECTIVE

To assess the impact of chronic renal insufficiency (CRI) on in-hospital major adverse cardiac events across the acute coronary syndrome (ACS) spectrum.

PATIENTS AND METHODS

From January 29, 2007, through July 29, 2007, 6 adjacent Middle Eastern countries participated in the Gulf Registry of Acute Coronary Events, a prospective, observational registry of 8176 patients. Patients were categorized according to estimated glomerular filtration rate into 4 groups: normal (>or=90 mL/min), mild (60-89 mL/min), moderate (30-59 mL/min), and severe CRI (<30 mL/min). Patients' characteristics and in-hospital major adverse cardiac events in the 4 groups were analyzed.

RESULTS

Of 6518 consecutive patients with ACS, 2828 (43%) had mild CRI, 1304 (20%) had moderate CRI, and 345 (5%) had severe CRI. In CRI groups, patients were older and had a higher prevalence of hypertension, diabetes mellitus, and dyslipidemia. On admission, these patients had a higher resting heart rate and frequently had atypical and delayed presentations. Compared with the normal estimated glomerular filtration group, CRI groups were less likely to receive antiplatelet drugs, beta-blockers, angiotensin-converting enzyme inhibitors, and statins and were less likely to undergo coronary angiography. In-hospital heart failure, cardiogenic shock, and major bleeding episodes were significantly higher in all CRI groups. In multivariate analysis, mild, moderate, and severe CRI were associated with a higher adjusted odds ratio (OR) of death (mild: OR, 2.1; 95% confidence interval [CI], 1.2-3.7; moderate: OR, 6.7; 95% CI, 3.9-11.5; and severe: OR, 12.0; 95% CI, 6.6-21.7).

CONCLUSION

Across the ACS spectrum, patients with CRI had a worse risk profile, had more atypical and delayed presentations, and were less likely to receive evidence-based therapy. Chronic renal insufficiency of varying stages is an independent predictor of in-hospital morbidity and mortality.