Should I Take Aspirin To Prevent Stroke or Heart Attack?

Aspirin is a unique drug, the prototypical  two-edged sword of pharmaceuticals.  It has the capability of stopping platelets, the sticky elements in our blood, from forming clots that cause strokes and heart attacks when arterial plaques rupture, but it increases the risk of serious bleeding into the brain or from the GI tract. Despite these powerful properties, aspirin is available over the counter and is very cheap, thus anyone can take it in any dosage they want. 

Who Should Take Aspirin?

For the last five years I’ve been advising my patients who have no evidence of atherosclerotic vascular disease against taking aspirin to prevent heart attack and stroke. Several comprehensive reviews of all the randomized trials of aspirin had concluded by 2011 that

The current totality of evidence provides only modest support for a benefit of aspirin in patients without clinical cardiovascular disease, which is offset by its risk. For every 1,000 subjects treated with aspirin over a 5-year period, aspirin would prevent 2.9 MCE and cause 2.8 major bleeds.
(MCE=major cardiovascular events, e.g. stroke, heart attack, death from cardiovascular disease)

Dr. Oz, on the other hand, came to St. Louis in 2011 to have  lunch with five hundred women and advised them all to take a baby aspirin daily (and fish oil, which is not indicated for primary prevention as I have discussed here). When I saw these women subsequently in my office I had to spend a fair amount of our visit explaining why they didn’t need to take aspirin and fish oil.
After reviewing available data, the FDA this week issued a statement recommending against aspirin use for the prevention of a first heart attack or stroke in patients with no history of cardiovascular disease (i.e. for primary prevention). The FDA pointed out that aspirin use is associated with “serious risks,” including increased risk of bleeding in the stomach and brain. As for secondary prevention for people with cardiovascular disease or those who have had a previous heart attack or stroke (secondary prevention), the available evidence continues to support aspirin use.

Subclinical Atherosclerosis and Aspirin usage

As I’ve discussed previously, however, many individuals who have not had a stroke or heart attack are walking around with a substantial burden of atherosclerosis in their arteries. Fatty plaques can become quite advanced in the arteries to the brain and heart before they obstruct blood flow and cause symptoms. In such individuals with subclinical atherosclerosis aspirin is going to be much more beneficial.
Guided Use of Aspirin

Large, complex atherosclerotic plaque in the carotid artery found by vascular screening in an individual with no history of stroke, heart attack, or vascular disease. This patient will definitely benefit from daily aspirin to prevent stroke or heart attack
We have the tools available to look for atherosclerotic plaques before they rupture and cause heart attacks or stroke. Ultrasound screening of the carotid artery, as I discussed here, is one such tool: vascular screening is an accurate, harmless and painless way to assess for subclinical atherosclerosis.
In my practice, the answer to the question of who should or should not take aspirin is based on whether my patient has or does not have significant atherosclerosis. If they have had a clinical event due to atherosclerotic cardiovascular disease (stroke, heart attack, coronary stent, coronary bypass surgery, documented blocked arteries to the legs) I recommend they take one 81 milligram (baby) uncoated aspirin daily. If they have not had a clinical event but I have documented by either

  • vascular screening (significant carotid plaque)
  • coronary calcium score (high score (cut-off is debatable, more on this in a subsequent post)
  • Incidentally discovered plaque in the aorta or peripheral arteries (found by CT or ultrasound done for other reasons)

then I recommend a daily baby aspirin (assuming no high risk of bleeding).
There are no randomized trials testing this approach but in the next few years several large aspirin trials will be completed and hopefully we will get a better understanding of who benefits most from aspirin for primary prevention.
Until then remember that aspirin is a powerful drug with potential for good and bad effects on your body. Only take it if you and your health care provider have decided the benefits outweigh the risks after careful consideration of your particular situation.


11 thoughts on “Should I Take Aspirin To Prevent Stroke or Heart Attack?”

  1. Doc said calcium score was excellent for my age as you also said. He said I was overweight at 185 and would like to see at least a 5 pound weigh loss in the next 4 months. BP was a bit high this time but normally good. He suggested going from 10 mg to 20 on the atorvastatin, continue exercising and check BP at home. Did not recommend low dose aspirin due to past stomach issues.

  2. Thanks, Doc, for your answer. Father died at age 57 probably due to heart problems. He drank and smoked which I do not do. Mother died at age 82, however, she had blocked carotid arteries and during surgery had a stroke. She also drank and smoked.
    I have a half brother (same father) who is in his 80’s and going strong and a half sister in her early 90’s doing okay. Bio sister has had numerous stents, but does not see the same doc as me. Almost got blindsided early on by another doc not through JHH who was recommending a stent based upon numbers and a treadmill test. I ran for the hills and went to JHH and so far so good.
    You say intermittent statin and aspirin. What would that look like, doc?

    • Doc said calcium score was excellent for my age as you also said. He said I was overweight at 185 and would like to see at least a 5 pound weigh loss in the next 4 months. BP was a bit high this time but normally good. He suggested going from 10 mg to 20 on the atorvastatin, continue exercising and check BP at home. Did not recommend low dose aspirin due to past stomach issues.

  3. Thank you, Doc, for the complete answer. I will know soon the score and discuss with the doctor who is head of a cardiology prevention unit via Johns Hopkins.

      • Agatston score of 33.6, at 34th percentile for subjects of the same age, gender, and race/ethnicity who are free of clinical cardiovascular disease and treated diabetes.
        Top normal ascending aorta measuring 3.9 cm.
        L main: 0
        LAD: 33.3
        LCx: 0
        RCA: 0.3
        Total calcium volume (mm^3): 31.6
        Total equivalent mass (mg CaHA): 5.29
        Total calcium score: 33.6
        No suspicious pulmonary nodule. No lung consolidation. Top normal ascending aorta measuring 3.9 cm at the level of the right renal artery. Limited noncontrast examination of the upper abdomen is unremarkable. Minimal vascular calcifications upper
        abdominal aorta. Minimal degenerative changes thoracic spine.
        Lipid panels:
        Total HDL LDL Tri VLDL-C
        8/30/13 139 32 81 130 26
        3/6/14 155 31 82 211 42
        7/18/14 156 37 100 93 19
        3/15/16 124 29 69 132 26
        11/28/16 209 32 130 236 47
        3/22/17 139 30 72 184 37
        11/22/17 156 32 89 175 35
        The 03.15.16 lipid results were on a vegan diet if memory serves me well.
        03.22.17 lipid results vegan diet.
        07.18.14 lipid results probably more low carb high fat diet showing low Triglycerides.
        See doc 12.06.17 Dr. Roger Blumenthal if you know that name from the

      • This score is good for your age. As I pointed out in my post on “Should All Men over age 60 take a statin” you have some atherosclerotic plaque primarily in your LAD and that is the norm for men of your age. I offer statins to this group (see “are you on the fence about statins”) and I discuss aspirin risks/benefits. Patient preference should play a big role in decision..
        Personally, I would take intermittent statin and aspirin.
        Your #s are interesting and reflect exactly what I tell patients about diet. LCHF raises your LDL but also your best HDL by far is on that. Conversely vegan gives nice low LDL but really low HDL.
        Calculated risk remains about the same.
        If both of your parents lived into 80s without significant CAD and you don’t like taking meds, then no rx is not unreasonable.

  4. No heart attack. No stent. Take low dose statin 10 mg. Just had calcium coronary test. Don’t know results yet. Age 67. Doc recommended low dose aspirin. Did not share his view. He said take Monday, Wednesday and Friday. Any thoughts, Doc?

    • If calcium zero, then no aspirin. If >100 definite aspirin.
      In between I would say personal preference.
      My score was 11 a few years ago and I take an aspirin every now and then but if I were advising a similar patient I would say take it daily.

    • My understanding is that there is no evidence that coating the baby aspirin lowers the risk of gastric ulcers and that it may substantially lower blood levels/absorption of the already low level aspirin, thereby lowering its efficacy


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