LOW DOSE ASPIRIN FOR PRIMARY PREVENTION OF CAD. MORE GOOD THAN HARM OR MORE HARM THAN GOOD?

I have often been asked, both my laypersons, patients and also physicians, whether they should take a bit of aspirin daily, low dose of course, for cardio-protection. My answer have always been the same. If aspirin protects the heart unequivocally, then we should have lobbied the government to add a bit of aspirin to our drinking water. But aspirin, even low dose, is not harmless. There are big issues with low dose aspirin.
This was re-emphasize in an article published in the June 6 issue of the Journal of the American Medical Association. The lead author is Dr Antonio Nicolucci of Consorzio Mario Negri Sud of Italy). Again this is a data base study. He went into the data base of the Italian National Health Service data to compare a group of Italians all without heart disease, and divided them into the group who were taking low dose aspirin ( less than 300mg daily ), and the group that was not taking aspirin. The group taking aspirin were new users from 2003-2008. There were 186,425 selected. They were followed for a mean of 5-7 years. During the follow-up period, there were 6,907 major bleeding events. 4,487 GI bleeds and 2,464 cranial bleeds. This will translate to an average of 2 more bleeds per 1,000 patients for a year. This danger roughly equals the number of cardiac events avoided with the low dose aspirin. In summary, you are avoiding a CAD event but substituting it for a major bleeding event, and a major stroke can be life-changing and catastrophic.
In a substudy, they found that in diabetics, aspirin did not produce so many bleeds, and the major bleeds in diabetic aspirin users roughly equals that in those diabetics not on aspirin, suggesting that low dose aspirin dose not work so well in diabetics.
Of course this paper did not look into the issue of colonic cancer prevention.
The bottom line is ( and there is plenty of evidence now ), that low dose aspirin in primary prevention of CAD has no role, as the harm may outweigh the good. We prevention as many CAD events and we cause as many bleeds, and some can be devastating, like a major stroke.
So, an aspirin a day, may not keep the doctors away.