Aspirin may be too risky for blanket primary prevention
Friday, 13 January 2012
Routine use of aspirin for primary prevention of cardiovascular disease should be avoided, warn UK researchers. They found that treatment brings only modest benefits in primary prevention of nonfatal myocardial infarction and total CVD events, while significantly increasing the risk of bleeding, in their meta-analysis involving more than 100,000 people.
Experts have warned that although certain higher-risk people without CVD may benefit from aspirin treatment, and the drug is highly effective for secondary prevention, as in current guidelines, “the data argue against the routine use of aspirin for primary prevention of CVD for individuals at low absolute risk of CVD”.
The authors of the UK study, published in the latest Archives of Internal Medicine, call for a reappraisal of guidelines on primary prevention of CVD, until further research can identify subsets of people likely to derive most benefit from aspirin.
They found that aspirin prophylaxis reduced total CVD events by 10% – mainly because rates of non-fatal MI were cut by 20% – but did not significantly reduce mortality from either CVD or cancer. It also significantly increased the risk of ‘nontrivial’ bleeding events, by more than 30%.
The authors commented: “Despite important reductions in nonfatal MI, aspirin prophylaxis in people without prior CVD does not lead to reductions in either cardiovascular death or cancer mortality.
“Because the benefits are further offset by clinically important bleeding events, routine use of aspirin for primary prevention is not warranted and treatment decisions need to be considered on a case-by-case basis.”
They conclude that until there is more research to show which subgroups of people without existing CVD might benefit most from aspirin prophylaxis: “A reappraisal of current guidelines appears to be warranted, particularly in countries where a large number of otherwise healthy adults are prescribed aspirin, since a significant proportion of them may develop bleeding complications.”