Aspirin for primary prevention: yes or no?

Area of Science:

• Cardiovascular Medicine
• Preventive Cardiology
• Clinical Pharmacology

Background:

• Aspirin is widely used for cardiovascular disease (CVD) primary prevention.
• Recent meta-analyses question the net benefit-harm balance of aspirin therapy.
• Current guidelines recommend aspirin based on CVD risk stratification.

Purpose of the Study:

• To evaluate the benefit versus harm of aspirin for primary CVD prevention.
• To stratify aspirin's net benefit by age, gender, and CVD risk category.
• To align findings with New Zealand's CVD risk assessment and management guidelines.

Main Methods:

• Calculated rates of vascular events avoided and major extracranial bleeds from the Anti-Thrombotic Trialists' (ATT) Collaboration meta-analysis.
• Applied these rates to different CVD risk categories.
• Determined net benefit or harm for aspirin monotherapy and in combination with lipid-lowering and blood pressure-lowering therapies.

Main Results:

• Aspirin monotherapy provides benefits outweighing harms for individuals up to 80 years old with a five-year CVD risk exceeding 15%.
• For individuals over 80, the harms of aspirin may exceed the benefits in primary prevention.
• For men aged 70-79, the additional benefit of aspirin is marginal when added to lipid and blood pressure-lowering therapies.

Conclusions:

• The study supports current guidelines recommending aspirin for primary CVD prevention in individuals with a five-year CVD risk of 15% or greater, up to age 80.
• For men aged 70-79, prioritizing lipid and blood pressure-lowering therapies before considering aspirin is advised.
• The benefit-harm profile of aspirin in primary CVD prevention is age and risk-dependent.