1. The Use of Aspirin for Primary Prevention of Cardiovascular Diseases
Naama Hermann
Pnimit B, Tel Hashomer

2. Aspirin
Hippocrates described salicylic acid as a bitter willow bark extract that eases pains and reduces fever.
Synthetic salicylate first manufactured in 1897
Mechanism discovered in 1971
The modern derivative named after St Aspirinius, the patron saint protecting from headaches.
ערבה

3. Aspirin
Analgesic, antipyretic, anti-inflammatory and antiaggregant agent
Irreversibly inhibits cyclo-oxygenase (COX-1 and 2)
Decrease formation of precursors of prostaglandins from arachidonic acid
Affects platelet function by preventing formation of the aggregating agent thromboxane A2

4. Aspirin for All!

5. Aspirin for All! The guidelines
U.S. Preventive Services Task Force
Grade A recommendation chemoprevention for adults at increased risk (10-year CHD risk ≥ 6%)
American Heart Association
Low-dose aspirin primary prevention in adults at higher risk of coronary heart disease (especially those with a 10-year CHD risk ≥ 10%)
Joint British Society (British Cardiac Society, British Hypertension Society, Diabetes UK, HEART UK, Primary Care Cardiovascular Society, The Stroke Association)
Aspirin 75 mg daily recommended for all people over the age of 50 with total CVD risk > 20%, and in selected people with diabetes (> 50 years, had the disease for over 10 years, or receiving treatment for hypertension)

6. Aspirin for Primary Prevention of CVS Diseases
Do the benefits outweigh the harms?
Is there a benefit??

7. Aspirin in the primary and secondary prevention of vascular disease: collaborative meta-analysis of individual participant data from randomised trials Antithrombotic Trialists' (ATT) Collaboration Lancet May 30; 373(9678): 1849–1860
Meta-analyses of six primary prevention trials (95,000 individuals) comparing serious vascular events (MI, stroke, or vascular death)
Increased major gastrointestinal and other extracranial bleeds (0·10% vs 0·07% per year)
Allocation to aspirin had no significant effect on fatal stroke, coronary heart disease or other vascular causes of death

8. Antithrombotic Trialists' (ATT) Collaboration
the same group that wrote the original 2002 aspirin primary-prevention meta-analysis, published in the BMJ
Credited by many to have been the paper that cemented the role of low-dose aspirin in primary prevention
Claim critical typo in the original paper: the final sentence reads: "For most healthy individuals, however, for whom the risk of a vascular event is likely to be substantially less than 1% a year, daily aspirin may well be appropriate."
A correction swiftly issued by the BMJ noted that final word should, in fact, be inappropriate.

9. Aspirin for Asymptomatic Atherosclerosis (AAA) study European Society of Cardiology (ESC), August 2009
3350 participants allocated randomly to enteric coated aspirin 100 mg once daily or placebo
Mean age 62
No history of vascular disease
Asymptomatic atherosclerosis
indicated by ABI ≤0.95
mean follow-up 8.2 years

10. Primary end-point results for aspirin vs placebo
Aspirin (n=1675), n (%)
Placebo (n=1675), n (%)
Fatal coronary event
28 (1.7)
18 (1.1)
Fatal stroke
7 (0.4)
12 (0.7)
Nonfatal coronary event
62 (3.7)
68 (4.1)
Nonfatal stroke
37 (2.2)
38 (2.3)
Coronary revascularization
24 (1.4)
20 (1.2)
Peripheral revascularization
23 (1.4)
Adverse events with aspirin vs placebo
Adverse event
Aspirin (n=1675), n (%)
Placebo (n=1675), n (%)
Major hemorrhage
34 (2.0)
20 (1.2)
Gastrointestinal ulcer
14 (0.8)
8 (0.5)
Fowkes G. European Society of Cardiology 2009 Congress; August 30, 2009; Barcelona, Spain.

11. Aspirin for Asymptomatic Atherosclerosis (AAA) study European Society of Cardiology (ESC), 2009
No difference in number of primary and secondary endpoint events
Primary endpoint: an initial fatal / nonfatal coronary event, stroke or revascularization
secondary endpoint - All-cause mortality
fatal coronary events more likely with aspirin than with placebo treatment (1.7% vs. 1.1%)
Gastric ulcers more frequent with aspirin use (0.8% vs. 0.5%).
Interestingly, cancer mortality was higher in the placebo group than in the aspirin group, Fowkes noted
No support for the routine use of aspirin for the prevention of vascular events in the context of ABI screening of the general population

12. Current evidence does not identify a worthwhile net benefit
Don’t use aspirin for primary prevention of cardiovascular disease Helen Barnett et al, BMJ 2010;340:c1805
Current evidence does not identify a worthwhile net benefit
No justification even in specific subgroups with high predicted risk, HTN or DM
The routine practice of Aspirin prophylaxis should be abandoned
Review patients currently receiving treatment