In patients without a history of cardiovascular disease, aspirin prevents deaths as well as myocardial infarction and ischemic stroke but increases hemorrhagic stroke and major bleeding when used in primary prevention of cardiovascular disease.
Abstract
Objective
The lack of a mortality benefit of aspirin in prior meta-analyses of primary prevention trials of cardiovascular disease has contributed to uncertainty about the balance of benefits and risks of aspirin in primary prevention. We performed an updated meta-analysis of randomized controlled trials of aspirin to obtain best estimates of the effect of aspirin on mortality in primary prevention.
Methods
Eligible articles were identified by searches of electronic databases and reference lists. Outcomes of interest were all-cause mortality, cardiovascular mortality, myocardial infarction, stroke, and bleeding. Data were pooled from individual trials using the DerSimonian-Laird random-effects model, and results are presented as relative risk (RR) and 95% confidence intervals (CIs).
Results
Nine randomized controlled trials enrolling 100,076 participants were included. Aspirin reduced all-cause mortality (RR 0.94; 95% CI, 0.88-1.00), myocardial infarction (RR 0.83; 95% CI, 0.69-1.00), ischemic stroke (RR 0.86; 95% CI, 0.75-0.98), and the composite of myocardial infarction, stroke, or cardiovascular death (RR 0.88; 95% CI, 0.83-0.94), but did not reduce cardiovascular mortality (RR 0.96; 95% CI, 0.84-1.09). Aspirin increased the risk of hemorrhagic stroke (RR 1.36; 95% CI, 1.01-1.82), major bleeding (RR 1.66; 95% CI, 1.41-1.95), and gastrointestinal bleeding (RR 1.37; 95% CI, 1.15-1.62). A lack of availability of patient-level data precluded exploration of benefits and risks of aspirin in key subgroups.
Conclusion
Aspirin prevents deaths, myocardial infarction, and ischemic stroke, and increases hemorrhagic stroke and major bleeding when used in the primary prevention of cardiovascular disease.
To read this article in its entirety, please visit our website.
— Nina Raju, MD, MsC, Magdalena Sobieraj-Teague, MBBS, Jack Hirsh, MD, Martin O’Donnell, MD, PhD, John Eikelboom, MD, MsC
This article originally appeared in the July 2011 issue of The American Journal of Medicine.
