Antiplatelet benefits ‘uncertain’ in chronic kidney disease
MedWire News: Antiplatelet treatment may do more harm than good in patients with acute coronary syndromes (ACS) or those undergoing percutaneous coronary revascularization who also have chronic kidney disease (CKD), show results of a systematic review and meta-analysis.
The review, conducted by Giovanni Strippoli (Consorzio Mario Negri Sud, Santa Maria Imbaro, Italy) and colleagues, shows that glycoprotein IIb/IIIa inhibitors or clopidogrel given in addition to standard care have little or no effect on death, myocardial infarction, or coronary revascularization and may increase major bleeding in these patients.
And while antiplatelet therapy may reduce myocardial infarction in people with CKD and stable cardiovascular disease, its effects on stroke and mortality are uncertain.
The researchers explain that antiplatelet agents are widely used to prevent cardiovascular events by inhibiting intravascular thrombosis, but treatment effects may differ in people with CKD because atherosclerotic disease is less prevalent than in the general population, and bleeding hazards are greater because of impaired hemostasis.
To summarize the benefits and harms of antiplatelet agents in people with CKD, paying special attention to cardiovascular events, mortality, and bleeding, Strippoli and team reviewed randomized trials that compared antiplatelet agents with placebo, standard care, or no treatment in adults with CKD .
They identified nine trials involving 9969 individuals who had ACS or were undergoing percutaneous coronary intervention and were considered at high risk for subsequent vessel closure. Patients in these trials were treated with glycoprotein IIb/IIIa inhibitors (abciximab, eptifibatide, or tirofiban; seven trials, 5471 participants) or clopidogrel (two trials, 4498 participants), plus aspirin with or without heparin.
A further 31 trials involving 11,701 individuals with CKD and stable or no cardiovascular disease were identified. These trials generally involved administration of aspirin, dipyridamole, aspirin and dipyridamole, or a thienopyridine (clopidogrel or ticlopidine).
The researchers report in the Annals of Internal Medicine that, compared with standard care alone, antiplatelet therapy plus standard care had little or no effect on all-cause or cardiovascular mortality or on myocardial infarction (nonsignificant relative risks [RRs] of 0.89-0.96) in patients with ACS. Antiplatelet treatment was, however, associated with increased risks for minor and major bleeding, at RRs of 1.47 and 1.40, respectively.
Among patients with stable or no cardiovascular disease, antiplatelet agents were associated with a significantly reduced risk for myocardial infarction compared with standard treatment (RR=0.66) but had nonsignificant effects on all-cause (RR=0.87) and cardiovascular mortality (RRs=0.91). In these patients, the risk for minor bleeding was significantly increased with antiplatelet therapy (RR=1.70). There was no significant impact on major bleeding, overall, but the RR was 1.55 when the researchers included only trials with a duration of 1 year or more.
The effects on stroke were unclear in both groups of patients, the researchers remark.
They note that, in general, the evidence was of low or very-low quality, with considerable variation in trial duration and heterogeneity in the definitions and assessment of bleeding outcomes. There was also a strong reliance on subgroup data from major trials, particularly for antiplatelet treatment in acute cardiovascular disease.
"Considering the totality of current evidence, using antiplatelet and related agents to prevent cardiovascular events in people with CKD may be prudent only in clinical trials that can further define the role of these drugs," Strippoli et al remark.
They conclude: "Bleeding hazards and lack of clear efficacy in reducing cardiovascular morbidity and mortality need to be acknowledged when patients with CKD are being counseled about acute or long-term antiplatelet therapy."
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By Laura Cowen