Aspirin in the primary and secondary prevention of vascular disease: collaborative meta-analysis of individual participant data from randomised trials

By C. Baigent, L. Blackwell, R. Collins, J. Emberson, J. Godwin, R. Peto, J. Buring, C. Hennekens, Patricia M. Kearney, T. Meade and 3 more. The Lancet, 2009

1,661 citations recorded by the source corpus.

Summary Background Low-dose aspirin is of definite and substantial net benefit for many people who already have occlusive vascular disease. We have assessed the benefits and risks in primary prevention. Methods We undertook meta-analyses of serious vascular events (myocardial infarction, stroke, or vascular death) and major bleeds in six primary prevention trials (95 000 individuals at low average risk, 660 000 person-years, 3554 serious vascular events) and 16 secondary prevention trials (17 000 individuals at high average risk, 43 000 person-years, 3306 serious vascular events) that compared long-term aspirin versus control. We report intention-to-treat analyses of first events during the scheduled treatment period. Findings In the primary prevention trials, aspirin allocation yielded a 12% proportional reduction in serious vascular events (0·51% aspirin vs 0·57% control per year, p=0·0001), due mainly to a reduction of about a fifth in non-fatal myocardial infarction (0·18% vs 0·23% per year, p<0·0001). The net effect on stroke was not significant (0·20% vs 0·21% per year, p=0·4: haemorrhagic stroke 0·04% vs 0·03%, p=0·05; other stroke 0·16% vs 0·18% per year, p=0·08). Vascular mortality did not differ significantly (0·19% vs 0·19% per year, p=0·7). Aspirin allocation increased major gastrointestinal and extracranial bleeds (0·10% vs 0·07% per year, p<0·0001), and the main risk factors for coronary disease were also risk factors for bleeding. In the secondary prevention trials, aspirin allocation yielded a greater absolute reduction in serious vascular events (6·7% vs 8·2% per year, p<0.0001), with a non-significant increase in haemorrhagic stroke but reductions of about a fifth in total stroke (2·08% vs 2·54% per year, p=0·002) and in coronary events (4·3% vs 5·3% per year, p<0·0001). In both primary and secondary prevention trials, the proportional reductions in the aggregate of all serious vascular events seemed similar for men and women. Interpretation In primary prevention without previous disease, aspirin is of uncertain net value as the reduction in occlusive events needs to be weighed against any increase in major bleeds. Further trials are in progress. Funding UK Medical Research Council, British Heart Foundation, Cancer Research UK, and the European Community Biomed Programme.

Subfields: Cardiology and Cardiovascular Medicine, Pharmacology, Surgery

View Paper: https://www.semanticscholar.org/paper/f3a5b8d3e64943a20b4defa1beb8e993d537d256

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In Cardiology and Cardiovascular Medicine

1. V. Basevi
2. E. Schiffrin
3. Massimo F. Piepoli
4. Stephen Burgess
5. S. Thompson

In Pharmacology

1. V. Basevi

In Surgery

1. G. Moneta
2. V. Basevi
3. Massimo F. Piepoli
4. Stephen Burgess
5. S. Thompson

Citations in the corpus

• Standards of Medical Care in Diabetes—2012 (2011, background): “Notably, differences between sexes in aspirin’s effects have not been observed in studies of secondary prevention (271).”
• Factors Influencing the Decline in Stroke Mortality (2013, neutral): “75), with no difference in the risk of stroke of unknown type, which accounted for approximately one third of stroke events in the randomized trials.(295) The risk of fatal stroke was nonsignificantly increased (OR, 1.”
• Standards of Medical Care in Diabetes—2013 (2012, neutral): “Notably, sex differences in aspirin’s effects have not been observed in studies of secondary prevention (311).”
• 2016 European Guidelines on cardiovascular disease prevention in clinical practice (2017, neutral): “In ameta-analysis of 16 trials comprising 17,000 individuals, the Antithrombotic Trialists’ Collaboration [464], aspirin treatment was associatedwith serious vascular events in 6.”
• 2017 ESC Guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation. (2017, neutral): “%) in patients with STEMI.163,164 While it is recommended to always treat the IRA, evidence supporting immediate (preventive) revascularization of additional significant coronary stenoses is conflicting.”
• The 2015 Canadian Hypertension Education Program recommendations for blood pressure measurement, diagnosis, assessment of risk, prevention, and treatment of hypertension. (2013, positive): “2 Antiplatelet therapy In secondary CV prevention, a large meta-analysis published in 2009 showed that aspirin administration yielded an absolute reduction in CV outcomes much larger than the absolute excess of major bleedings [657].”