Low-Dose Aspirin for Primary Prevention of Cardiovascular Events in Patients With Diabetes: A Meta-Analysis
ABSTRACT The use of low-dose aspirin for primary prevention of cardiovascular events in patients with diabetes is recommended by existing guidelines, but definitive evidence supporting its efficacy is lacking. The authors undertook a meta-analysis of published trials to determine the effect of low-dose aspirin for primary prevention of cardiovascular events in patients with diabetes.
Randomized controlled trials comparing low-dose aspirin versus placebo or no treatment in patients with diabetes (either exclusively or as a subgroup) with no previous history of cardiovascular disease were identified through MEDLINE and EMBASE databases.
Seven randomized controlled trials met the inclusion criteria. Two studies included exclusively patients with diabetes, whereas the remaining 5 studies included patients with diabetes as a subgroup. Two studies were excluded because they did not provide diabetes-specific data. Overall, aspirin was associated with a nonsignificant reduction in the hazard rate of the composite endpoint of major cardiovascular events compared with control (hazard ratio = 0.89, 95% confidence interval: 0.70-1.13, P = 0.33). Similarly, there was a nonsignificant reduction in the hazard rate of the individual endpoints of myocardial infarction, stroke, cardiovascular and all-cause mortality. The risk of major bleeding increased nonsignificantly with aspirin compared with control (relative risk = 3.02, 95% confidence interval: 0.48-18.86, P = 0.24).
The role of low-dose aspirin for primary prevention of cardiovascular events in patients with diabetes remains unproven, and its routine use cannot be justified at present. More trials are needed to definitively address this issue.
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ABSTRACT: Reduction of cardiovascular disease (CVD) events in patients with type 2 diabetes remains an area of intense interest and research. Recent trials of lower systolic blood pressure goals and combination lipid therapy have failed to show a significant reduction in CVD events in patients with diabetes. Antiplatelet agents are an additional option for CVD risk reduction in patients both with and without diabetes. However, two recent trials have questioned the role of aspirin in the primary prevention of CVD events in patients with diabetes. Although sub-analyses of larger trials have suggested a potential benefit of thienopyridine therapy in patients with diabetes, direct comparative trials are lacking and aspirin remains the appropriate first-line agent. Recent guidelines issued by the American Diabetes Association, American Heart Association, and American College of Cardiology Foundation on the use of aspirin for primary prevention in patients with diabetes remain the standard of practice. Two ongoing trials will help to address the question of the relative benefit of aspirin in patients with diabetes. The Aspirin and Simvastatin Combination for Cardiovascular Events Prevention Trial in Diabetes (ACCEPT-D) and A Study of Cardiovascular Events in Diabetes (ASCEND) are both randomized trials of 100 mg of aspirin compared to placebo and will enroll a combined 15,000 patients with diabetes between the two trials. Results may become available as soon as 2012.Current Cardiovascular Risk Reports 02/2011; 6(1). DOI:10.1007/s12170-011-0207-z
- Expert Review of Cardiovascular Therapy 03/2011; 9(3):253-5. DOI:10.1586/erc.11.10
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ABSTRACT: Aspirin has been recommended for the prevention of major adverse cardiovascular events (MACE, composite of non-fatal myocardial infarction, non-fatal stroke, and cardiovascular death) in diabetic patients without previous cardiovascular disease. However, recent meta-analyses have prompted re-evaluation of this practice. The study objective was to evaluate the relative and absolute benefits and harms of aspirin for the prevention of incident MACE in patients with diabetes. We performed a systematic review and meta-analysis on seven studies (N=11,618) reporting on the use of aspirin for the primary prevention of MACE in patients with diabetes. Two reviewers conducted a systematic search of electronic databases (MEDLINE, EMBASE, the Cochrane Library, and BIOSIS) and hand searched bibliographies and clinical trial registries. Reviewers extracted data in duplicate, evaluated the quality of the trials, and calculated pooled estimates. A total of 11,618 participants were included in the analysis. The overall risk ratio (RR) for MACE was 0.91 (95% confidence intervals, CI, 0.82-1.00) with little heterogeneity among trials (I2 0.0%). Secondary outcomes of interest included myocardial infarction (RR, 0.85; 95% CI, 0.66-1.10), stroke (RR, 0.84; 95% CI, 0.64-1.11), cardiovascular death (RR, 0.95; 95% CI, 0.71-1.27), and all-cause mortality (RR, 0.95; 95% CI, 0.85-1.06). There were higher rates of hemorrhagic and gastrointestinal events. In absolute terms, these relative risks indicate that for every 10,000 diabetic patients treated with aspirin, 109 MACE may be prevented at the expense of 19 major bleeding events (with the caveat that the relative risk for the latter is not statistically significant). The studies reviewed suggest that aspirin reduces the risk of MACE in patients with diabetes without cardiovascular disease, while also causing a trend toward higher rates of bleeding and gastrointestinal complications. These findings and our absolute benefit and risk calculations suggest that those with diabetes but without cardiovascular disease lie somewhere between primary and secondary prevention patients on the spectrum of benefit and risk. This underscores the importance of considering individual risk in clinical decision making regarding aspirin in those with diabetes.Cardiovascular Diabetology 04/2011; 10(1):25. DOI:10.1186/1475-2840-10-25 · 3.71 Impact Factor