Which Kind of Baby Aspirin Should I Take To Prevent Heart Attack? Chewable Versus Enteric Coated Versus Regular

The skeptical cardiologist recently asked his Eternal Fiancée to grab a bottle of baby aspirin  while she was at the local Walgreen’s. Aspirin or acetyl salicylic acid (ASA) comes in either a 325 mg dose or in a low dose which can be between 75 to 100 mg and is often called “baby” aspirin.
However, since a link between aspirin use and a potentially lethal disease called Reye’s syndrome was identified in the 1980s, no authorities recommend aspirin in children or babies, and the low dose ASA (LDASA) is primarily marketed and used for prevention of cardiovascular disease.
Although Bayer and Dr. Oz would have us believe that all individuals over the age of 55 should be taking LDASA, as I pointed out here in 2014, the FDA no longer recommends it for prevention of cardiovascular disease.
The US Preventive Services Task Force, on the other hand, recognizes certain individuals without heart disease who benefit from LDASA:

The USPSTF recommends initiating low-dose aspirin use for the primary prevention of cardiovascular disease (CVD) and colorectal cancer (CRC) in adults aged 50 to 59 years who have a 10% or greater 10-year CVD risk, are not at increased risk for bleeding, have a life expectancy of at least 10 years, and are willing to take low-dose aspirin daily for at least 10 years.
I’m 63  years old, so the USPTF recommendation for me to take LDASA is a little less enthusiastic:
The decision to initiate low-dose aspirin use for the primary prevention of CVD and CRC in adults aged 60 to 69 years who have a 10% or greater 10-year CVD risk should be an individual one. Persons who are not at increased risk for bleeding, have a life expectancy of at least 10 years, and are willing to take low-dose aspirin daily for at least 10 years are more likely to benefit. Persons who place a higher value on the potential benefits than the potential harms may choose to initiate low-dose aspirin.
Following my own advice (see here), I have started taking 81mg of aspirin regularly (well, when I remember) in order to prevent stroke and heart attack. I do have subclinical atherosclerosis with a plaque in my LAD, and I think the aspirin will make my platelets less sticky and less likely to form clots if my plaque ruptures, thereby reducing my chances of an acute heart attack.
I am willing to accept the increased risk of bleeding from the gastrointestinal tract and hemorrhagic stroke associated with LDASA use.

Previous to this I had been taking ASA from little sample bottles that Bayer sends to my office. These bottles are quite annoying as they are stuffed with cotton and contain very few pills making extrication of the tiny pills an exercise in futility (I am using this as an excuse for my lack of regularity in taking them).
There’s no reason to pay the premium for Bayer ASA despite the company’s advertising attempts to link inextricably their name with ASA.  Aspirin is aspirin, whether Bayer made it or Walgreens. In Bayer’s defense, their website has reasonable information on heart attacks and they appear to be giving aspirin away to people named Smith.

But what type of aspirin should you get? Enteric-coated, safety-coated, delayed release, chewable?

Chewable Aspirin

I asked the Eternal Fiancée to buy the cheapest baby aspirin possible.
She ended up buying a chewable formulation with orange flavoring, presumably aimed at children:
When I put one of these in my mouth I tasted the sickly sweet taste of an artificial sweetener. The ingredients are listed as: Dextrates, Ethyl Cellulose, FD&C Yellow 6 Aluminum Lake, Orange Flavor, Sodium Saccharin, Starch. Saccharine! Yikes!
The only reason to chew ASA is if you are having an acute heart attack.
In this situation, chew 4 of the LDASA or one regular 325 mg aspirin.  Chewing the aspirin makes the levels rise faster in your blood stream and can help dissolve the clot causing your heart attack more rapidly.
How do you know if you are having a heart attack? This is actually a very difficult question to answer with certainty. See here for a reasonable discussion.

Low Dose Aspirin: Enteric-Coated versus Non-coated

It is very difficult (perhaps impossible) to find low dose, non-chewable ASA that has not been “safety-coated” or “enteric-coated.” These formulations have become popular by promoting the idea that they are less likely to cause stomach pain or bleeding.
The concept is that the coating leads to delaying the aborption of the ASA until it reaches the small intestines where, presumably, it will do less damage. However, there is no good evidence to support lower bleeding risk with enteric-coasted (EC) ASA.
There is, on the other hand, very good evidence that therapeutic levels of aspirin in the bloodstream, and therefore the speed and efficacy of ASA in preventing heart attacks, is reduced by these “safety” formulations.
The most recent study showing this was published in 2017.
Volunteers were given either 325mg regular ASA or 325mg EC ASA and researchers looked at how each formulation effected platelet activity.  The onset of antiplatelet activity was determined by the rate and extent of inhibition of serum thromboxane B2(TXB2) generation.
The EC ASA took longer and was less effective at blocking platelet activity than plain ASA. Presumably, this translates into lower efficacy in preventing heart attacks and strokes.

Therefore,  if you feel like you are having a heart attack, chew ASA which is not enteric or safety-coated. Yes, you can chew a regular 325 mg ASA pill. Or you can chew 4 of the LDASA, preferably uncoated but still helpful if coated.
If it turns out you weren’t having a heart attack there is no down side to having chewed 325 mg ASA.

I just spent a fair amount of time trying to find non EC, non-chewable LDASA online and failed.

For the time being I will be swallowing daily the orange chewable LDASA and I will carry a bottle around in my satchel for emergency use.
Salicylically Yours,
N.B. Aspirin is generally recommended in secondary prevention of cardiovascular disease, ie. for those who have had heart attacks, stents or bypass surgery . For a good review of the evidence for this see here.


13 thoughts on “Which Kind of Baby Aspirin Should I Take To Prevent Heart Attack? Chewable Versus Enteric Coated Versus Regular”

  1. Yesterday I asked a question about Vazalore aspirin. If you answer my question in one of your blogs please don’t use my last name. Thank you.

    • Danie.,
      No worries. I never reveal information on patients/readers in my blog unless they fully approve beforehand.
      Dr P

  2. I just read your article about what type of baby aspirin to take. I have been taking chewable baby aspirin that I swallow since being put on aspirin therapy and a statin 3 years ago after getting a high CAC score (175) at age 48 . Do you have an opinion on the new Vazalore 81 mg that I have seen advertized? Its supposed to be just as effective as chewable but better for stomach because it releases after passing through stomach. I havent had problems with the aspirin yet but worry about using it for years and years. Vazalore is much more expensive but might be worth it, I was wondering if you had an opinion. Thanks, Daniel Minet

  3. EC aspirin, I would bet… a lot, just ends up in your toilet ( I have seen this ) as you took it. Thus, I stopped taking EC also because of all the junk in the tablet. Pure aspirin with food.
    Now, if you can show me how to reduce arterial plaque, that would be worthy of efforts.

    • Daniel,
      I have no clinical experience with Vazalore but a study has shown that compared to 325 mg aspirin it induces much less gastric ulceration.
      I haven’t seen studies utilizing 81 mg aspirin which is what most patients take.
      For patients with bleeding issues or gastric irritation from aspirin or a history of gastric ulcers it might be worth the extra cost.
      How much would it have cost you?
      Dr P

  4. What about a 50 yr old man with early signs of carotid plaque (by ultrasound) but has a zero calcium score (and no spleen more free circulating platelets)

    • The early carotid plaque is a sign of advanced atherosclerosis for his age. That plus the increase thrombotic risk of no spleen would make one benefit more from aspirin therapy.

  5. the nice thing about the flavored chew-able variety in the presence of (potential) heart attack in my experience is that it does not seem to play into the already-often-present nausea the way that the bitter “adult non-chewable” version does when you chew it. Vomiting is not your friend. Anecdotal experience in my work though — no one I know of has bothered to do any studies on the statistical odds of puking when nauseous people chew bitter pills, often without much water as a chaser. I had seen studies that said swallowing a non-coated aspirin is no slower in effectiveness than chewing it, but I’ve not looked up more recent ones so I presume from your comments that that has changed. I guess if you are not having a heart attack and are feeling particularly disinterested in the additional weird ingredients, you could use a pill splitter on a regular aspirin. If for the various reasons (poor dose availability or weird pricing structures) one often uses a splitter anyway, it’d just be one more of those.

  6. Ask your Eternal Fiancee to buy you a pair of tweezers to take to your office. They are great for removing cotton from pill bottles, and your free aspirin from Bayer will soon pay for the tweezers.

  7. Great article! So funny- this morning I was wondering about what type of Aspirin to take and this timely article answers the question. Thanks for posting it.
    What is your opinion on using a daily baby aspirin for those who have elevated lipoprotein a ( lp(a) )? I heard high levels of lp(a) make blood sticky.

  8. Would one of the NOACs have a similar positive effect on avoidance of MI as the antiplatelet aspirin you speak of?
    I’m thinking of the likes of apixaban taken for paroxysmal afib.
    Of course, one doesn’t want to take both and bleed!


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