Aspirin for Primary-Prevention Among Diabetics (June 2010)
New Statement Urges Caution for Primary-Prevention Aspirin in Diabetics
A new scientific statement on the use of aspirin for the primary prevention of cardiovascular disease in patients with diabetes recommends that low-dose aspirin is "reasonable" in those with no history of vascular disease but who are at an increased 10-year risk of cardiovascular events [1].
The new recommendations, from a joint statement of the American Diabetes Association (ADA), the American Heart Association (AHA), and the American College of Cardiology (ACC), essentially call for tighter criteria for aspirin use in the diabetic population. The organizations state that only men older than 50 and women older than 60 who have one or more additional major risk factors should be treated with aspirin for primary prevention of cardiovascular events.
The group recommends low-dose aspirin, 75 mg/d to 162 mg/d, for adults with diabetes and no history of cardiovascular disease but who are at an increased risk based on age and at least one additional cardiovascular disease risk factor, such as smoking, dyslipidemia, hypertension, family history of disease, and albuminuria. It is a class IIa recommendation with a level of evidence B.
Aspirin is not recommended for high-risk diabetic patients who are also at risk for bleeding and is not recommended for individuals at low risk of cardiovascular events. For those at intermediate risk, the use of aspirin can be "considered" until further research is available.
The recommendations of the group are based on an analysis of the available evidence with aspirin in primary prevention of cardiovascular disease for diabetic patients.
With no single study providing definitive results, the writing committee attempted to reconcile the findings by examining existing meta-analyses, such as the one performed by the Oxford Antithrombotic Treatment Trialists' (ATT) collaboration [2]. With the ATT meta-analysis, one that included 4000 diabetic patients from six clinical trials, the researchers found that aspirin reduced the risk of vascular events 12%, with the largest reduction in nonfatal MI.
Two of the newer primary-prevention trials, however, the Japanese Primary Prevention of Atherosclerosis with Aspirin for Diabetes (JPAD) and the Prevention of Progression of Arterial Disease and Disease (POPADAD), included diabetic patients only, and both failed to show any benefit of aspirin therapy in the primary prevention of cardiovascular events of diabetic patients. When JPAD, POPADAD, and the Early Treatment of Diabetic Retinopathy Study (ETDRS) were included with the six trials from the ATT collaboration, aspirin was associated with a 9% non significant reduction in coronary heart disease events.
In light of the summary of the existing literature and the more conservative recommendations, the authors said that doctors should use clinical judgment when treating a patient with diabetes.
The ADA, AHA, and ACC recommend various risk-assessment tools that can be used in patients with diabetes, including the UKPDS Risk Engine, the ARIC Coronary Heart Disease Risk Calculator, and the ADA Risk Assessment Tool.
Two studies assessing the safety and benefit of aspirin for the prevention of cardiovascular events among patients with diabetes are ongoing. Those trials, A Study of Cardiovascular Events in Diabetes (ASCEND) and Aspirin and Simvastatin Combination for CV Events Prevention Trial in Diabetes (ACCEPT-D), are still some years away from completion.
REFERENCES:
- Pignone M, Alberts MJ, Colwell JA, et al. Aspirin for primary prevention of cardiovascular disease in people with diabetes. Circulation 2010; DOI:10.1161/CIR.0b013e3181e3b133. Available at: http://circ.ahajournals.org. 20508178J Am Coll Cardiol 2010; DOI:10.1016/j.jacc.2010.04.003. Available at: http://content.onlinejacc.org. Diabetes Care 2010; 33:1395-1402.
- Antithrombotic Trialists' (ATT) Collaboration. Aspirin in the primary and secondary prevention of vascular disease: collaborative meta-analysis of individual participant data from randomised trials. Lancet 2009; 373:1849-1860.
