Does Aspirin Prevent Heart Attacks?
Yes, low-dose aspirin (typically 75-162 mg daily) reduces the risk of heart attacks in certain high-risk people by inhibiting platelet clumping, which prevents blood clots in arteries.[1][2] Major trials like the Physicians' Health Study and ISIS-2 showed 20-44% reductions in cardiovascular events for those with prior heart issues or high risk.[1][3]
Who Benefits Most from Aspirin Therapy?
- Secondary prevention: Proven for people with a history of heart attack, stroke, or stable angina—reduces recurrence by about 25%.[2][4]
- Primary prevention: Recommended only for select adults aged 40-70 at high 10-year cardiovascular risk (>10%) with low bleeding risk, per USPSTF guidelines.[5] Not routine for low-risk people under 60 due to bleeding outweighing benefits.[5]
What Do Guidelines Say?
| Group | Recommendation | Source |
|-------|----------------|--------|
| Prior heart attack/stroke | Daily low-dose aspirin | AHA/ACC[2][4] |
| High-risk diabetes (men 50+, women 60+) | Consider if low bleed risk | ADA[6] |
| General adults 60+ | Avoid starting routinely | USPSTF 2022[5] |
| Low-risk under 60 | Do not initiate | USPSTF 2022[5] |
What Are the Risks and Side Effects?
Bleeding is the main concern—gastrointestinal (2-4x higher risk) and intracranial (slight increase).[1][7] Absolute risk rises with age, alcohol use, NSAIDs, or anticoagulants. Net benefit flips negative for many over 70.[5] Always weigh with a doctor; alternatives like statins may suffice for primary prevention.
How Does It Compare to Other Options?
- Vs. statins: Aspirin targets clots; statins lower cholesterol—often combined for high-risk patients.[4]
- Vs. clopidogrel: Aspirin is first-line and cheaper; clopidogrel for aspirin-intolerant.[2]
- Emerging alternatives: Ticagrelor or rivaroxaban in trials for specific cases, but aspirin remains standard due to cost and evidence.[3]
When Should You Start or Stop?
Start only under medical advice after risk assessment (e.g., ASCVD calculator).[4] Stop if surgery planned (7-10 days prior), uncontrolled bleeding, or peptic ulcer history.[2] Recent studies like ASPREE (2018) found no primary prevention benefit in healthy elderly, prompting guideline shifts.[5][8]
[1]: Antithrombotic Trialists' Collaboration, BMJ 2009
[2]: AHA/ACC Guideline, Circulation 2016
[3]: ISIS-2 Trial, Lancet 1988
[4]: 2019 ACC/AHA Primary Prevention Guideline
[5]: USPSTF Aspirin Recommendation, JAMA 2022
[6]: ADA Standards of Care 2023
[7]: McQuilten et al., Lancet Haematology 2020
[8]: ASPREE Trial, NEJM 2018