Don’t use aspirin for primary prevention of cardiovascular disease

Editor,

We read the recent paper by Barnett, Burrill, and Iheanacho, with a
great
interest (1). In the much-publicised “HOT” studying patients with
hypertension, although aspirin use significantly (p=0·002) reduced acute
myocardial infarction, the benefit became non-significant when all
myocardial infarctions, including silent, were considered (2). Of
particular
interest to us are the “barriers to change”, which the authors perceive to
be
responsible for wide spread use of aspirin in primary prevention.

The British Hypertension Society (BHS) has published guidelines and
recently
reaffirmed its advise regarding the use of aspirin in patients with
hypertension (3-4). However, we notice that in many patients attending our

hypertension clinic, aspirin was being prescribed or withheld
inappropriately.

We therefore conducted a survey of 734 patients to investigate the use or
misuse of aspirin (defined as per the BHS guidelines) in our clinic in
2005.
The patients were divided in four groups, ie. taking aspirin which is not
indicated (no target organ damage & 10-year cardiovascular risk below
20%
or blood pressure not controlled), on aspirin and should be been taking
aspirin (target organ damage or 10-year cardiovascular risk above 20% and
blood pressure controlled), not on aspirin and shouldn’t be on aspirin (no

target organ damage & 10-year cardiovascular risk below 20% or blood
pressure not controlled), and lastly not taking aspirin although should
have
been prescribed (target organ damage or 10-year cardiovascular risk above
20% and blood pressure controlled). Although most of patients were
correctly
either taking or not taking aspirin, we found that 78 (10%) patients were
taking aspirin despite no clear-cut indication and 107 (16%) patients were
not
prescribed aspirin although they did meet the BHS criteria (Figure). We
feel
that in the absence of clear-cut guidelines from national and
international
bodies (possibly due to lack of randomised, placebo controlled adequately
sized trials) both general practitioners as well as hospital doctors
remain
unsure when it comes to aspirin prescription or stoppage.

References

1. Barnett H, Burrill P, Iheanacho I.Don't use aspirin for primary
prevention
of cardiovascular disease. BMJ 2010;340:c1805

2. Hansson L, Zanchetti A, Carruthers SG, Dahlöf B, Elmfeldt D, Julius S,
et
al. Effects of intensive blood-pressure lowering and low-dose aspirin in
patients with hypertension: principal results of the Hypertension Optimal
Treatment (HOT) randomised trial. HOT Study Group. Lancet 1998;351:1755-
62

3. Williams B, Poulter NR, Brown MJ, Davis M, McInnes GT, Potter JP, et
al.
The BHS guidelines working party. British Hypertension Society guidelines
for
hypertension management, 2004 - BHS IV: Summary. BMJ 2004;328:634-640

4. Sever PS, BHS working party. Aspirin and primary prevention: BHS
reaffirms its guidance. BMJ 2010;340:c1183

Competing interests:
None declared