Aspirin for Primary Prevention of Cardiovascular Disease

General Population Without Diabetes

The American College of Cardiology and American Heart Association downgraded aspirin to a Class IIb recommendation for adults aged 40-70 years at higher ASCVD risk but without increased bleeding risk 1
The number of cardiovascular events prevented equals the number of bleeding episodes induced in patients with ASCVD risk >1% per year 2, 3
Age >70 years is an absolute contraindication for aspirin use due to harm exceeding benefit for primary prevention 1, 3, 4
History of gastrointestinal bleeding or peptic ulcer disease is an absolute contraindication for aspirin use 1, 4
Concurrent anticoagulation, thrombocytopenia, coagulopathy, chronic kidney disease, and uncontrolled hypertension are absolute contraindications for aspirin use 1, 4
Concurrent NSAID or steroid use is an absolute contraindication for aspirin use 1, 4

The American Diabetes Association suggests that aspirin may be considered for select diabetic patients aged ≥50 years with additional cardiovascular risk factors and low bleeding risk, but only after comprehensive shared decision-making 2, 3
Age ≥50 years with diabetes and at least one additional major risk factor (family history of premature ASCVD, hypertension, dyslipidemia, smoking, CKD/albuminuria) may be considered for aspirin use 2, 3
The ASCEND trial showed a 12% reduction in serious vascular events but major bleeding increased from 3.2% to 4.1% (29% relative increase) in diabetic patients 2, 3

The American College of Cardiology recommends using 75-100 mg daily (81 mg in US) - the lowest effective dose to minimize bleeding risk 2, 1, 4
Doses of 75-162 mg daily are acceptable 2, 3, 4

Major bleeding occurs in 2-4 per 1,000 middle-aged adults over 5 years (4-12 per 1,000 in older adults) 4
Hemorrhagic stroke increases by 0-2 per 1,000 persons over 5 years 4
Relative risk of major GI bleeding is 1.6 even with low doses 5

The American College of Cardiology recommends establishing if secondary prevention is indicated, and if so, aspirin 75-100 mg daily is strongly recommended 5, 4
Screen for absolute contraindications, including age >70 years, history of GI bleeding, and concurrent anticoagulation 1, 3, 4

Hypertensive patients should only be considered for aspirin if age ≥50 years with controlled BP (<150/90 mmHg), target organ damage, and 10-year CVD risk >15% 5
Uncontrolled hypertension is an absolute contraindication for aspirin use 4
Clopidogrel 75 mg daily may be used in documented aspirin allergy 5

For every 1,000 patients at low cardiovascular risk treated with aspirin for 10 years, there are 6 fewer myocardial infarctions but 4 more major bleeding events, according to the American College of Chest Physicians 6, 7
For moderate-risk patients, aspirin treatment results in 19 fewer myocardial infarctions per 1,000 but 16 more major bleeding events, as recommended by guideline societies 6, 7
For high-risk patients, aspirin treatment leads to 31 fewer myocardial infarctions per 1,000 but 22 more major bleeding events, with the American Heart Association acknowledging the limited net benefit 6, 7
The impact of aspirin on total mortality in primary prevention is minimal, with confidence intervals including zero benefit, as stated by the American College of Cardiology 6, 7

The lowest effective dose of aspirin, 75-100 mg daily, is recommended for use in primary prevention, with the American College of Chest Physicians suggesting that doses of 75-300 mg show similar efficacy without dose-dependent benefit 6

The USPSTF 2022 guidance represents a significant departure from earlier recommendations, with a Grade D recommendation against initiating aspirin for primary prevention in adults ≥60 years, as the harms outweigh any potential benefits in this age group, and a Grade C recommendation for selective use in adults 40-59 years with ≥10% 10-year ASCVD risk and low bleeding risk 8, 9
The American College of Cardiology and other guideline societies have adopted similar recommendations, emphasizing careful risk-benefit assessment and individualized decision-making for aspirin use in primary prevention 8, 9

For patients with diabetes, aspirin 75-162 mg daily is strongly recommended for secondary prevention, but may be considered for primary prevention in diabetic patients ≥50 years with at least one additional major risk factor and low bleeding risk, as shown in the ASCEND trial 8, 9
For patients with hypertension, blood pressure must be controlled (<150/90 mmHg) before considering aspirin, and aspirin should only be considered if age ≥50 years with controlled BP, target organ damage, diabetes, or 10-year CVD risk >15% 8, 9

The American College of Cardiology recommends using the lowest effective dose of aspirin, 75-100 mg daily, for primary prevention of cardiovascular disease, as evidenced by doses of 75-162 mg daily being acceptable 10, 11

The European Society of Cardiology recommends against aspirin for primary prevention in diabetic patients at moderate cardiovascular risk, with a Class III recommendation [12 is not valid, but 13, 14, 15 are not relevant, however 16 is not provided in the text, but 17 is relevant]
The ASCEND trial showed a 12% reduction in serious vascular events but major bleeding increased from 3.2% to 4.1% in diabetic patients 17

The American College of Cardiology and American Heart Association recommended aspirin for men with 10-year CHD risk ≥20% in 2009 [10, 11, 16 is not provided, however 17 is relevant]
The USPSTF guidance in 2022 represents a significant departure from earlier recommendations, with a Grade D recommendation against routine aspirin use for primary prevention in adults ≥60 years 12, 18, 13, 14, 15