Aspirin Therapy for Atherosclerotic Cardiovascular Disease

Introduction to Aspirin Recommendations

The American College of Cardiology recommends aspirin 75-100 mg daily for primary prevention in individuals at high risk of atherosclerotic cardiovascular disease (≥10% 10-year risk), as the net benefit increases with ASCVD risk, generally exceeding bleeding risks at ≥10% 10-year risk 1, 2

For established ASCVD, the American Heart Association recommends a loading dose of 162-325 mg orally and a maintenance dose of 75-100 mg daily, with an uncoated formulation preferred, as this dosing exceeds the minimal effective dose for platelet thromboxane A₂ suppression while allowing for interindividual variability 1, 2
The European Society of Cardiology suggests that higher maintenance doses (300-325 mg daily) offer no additional benefit and increase bleeding risk 1

The American Diabetes Association recommends a daily dose of 75-162 mg for patients with ≥10% 10-year ASCVD risk, with the 75-100 mg range preferred as it provides equivalent efficacy with lower bleeding rates compared to higher doses 3, 4
For patients with diabetes and established ASCVD, the American College of Cardiology recommends using 75-162 mg daily 4

High-risk criteria warranting aspirin consideration include a 10-year ASCVD risk ≥10% (some guidelines suggest ≥20% for strongest benefit), men ≥50 years or women with diabetes plus ≥1 additional major risk factor, and established coronary, cerebrovascular, or peripheral arterial disease 3, 4, 5

The absolute benefits substantially outweigh bleeding risks in moderate-to-high risk settings (≥3% annual vascular event rate, equivalent to ≥10% 10-year risk), with the excess bleeding risk as high as 5 per 1,000 per year, but for adults with ASCVD risk >1% per year, events prevented typically equal or exceed bleeding episodes induced 5, 4

Absolute contraindications include documented aspirin allergy or hypersensitivity, active bleeding or high bleeding risk, recent gastrointestinal bleeding, and clinically active hepatic disease 4, 3, 5
For aspirin-intolerant patients, the American College of Cardiology recommends clopidogrel 75 mg daily as the alternative for secondary prevention, and aspirin desensitization is preferred when possible to allow dual antiplatelet therapy 4, 2

The American Heart Association advises against using NSAIDs for pain management in patients on aspirin, as NSAIDs are associated with increased MACE risk in patients with and without prior cardiac disease, and instead recommends considering acetaminophen or short-acting opioids as alternatives 1, 2, 5
Uncoated aspirin should be chewed for acute presentations to achieve faster antiplatelet action, and high-dose aspirin should not be continued long-term 1

For patients on ticagrelor, the American College of Cardiology recommends aspirin doses ≤100 mg daily, and for patients requiring anticoagulation, aspirin discontinuation is appropriate after 1-4 weeks post-PCI while continuing P2Y12 inhibitor with full-dose anticoagulant 2