Expert on review questioning use of statins to prevent cardiovascual disease

A review by the Cochrane Collaboration of medical studies on the use of cholesterol-lowering drugs (statins), suggests the drugs have negligible benefit for those without a history of cardiovascular disease.

Statins have well-documented benefits for those with a history of cardiovascular disease, which is the leading cause of death in New Zealand*. However the review of 14 randomized control trials involving 34,272 patients and stretching back to the mid 1990s found that statins helped reduce death rates but only by a tiny fraction for people at low risk of heart disease.

The researchers pointed out that even that tiny benefit as a preventative measure may be in doubt as some of the mainly industry-funded studies were poorly designed.

The SMC asked local experts to comment on the research and the use of statins in New Zealand. Further comments will be posted on the Science Media Centre website.

Professor Norman Sharpe, Medical Director of the National Heart Foundation of New Zealand and Professor Emeritus in the University of Auckland, comments:

“There is complete agreement worldwide that statins should be given routinely to people with clinically manifest CVD ie for secondary prevention.

“There is also agreement that they should be used for high risk primary prevention.

‘The ongoing debate is around “how low to go” with risk ie how far to extend statin use into the intermediate and lower risk groups.

“The currently agreed NZ guideline recommendation is that drug treatment of all modifiable risk factors is indicated simultaneously with lifestyle advice for people with an estimated CVD risk of an event of >15% over 5 years.

“Consideration of treatment on an individual basis for those in the moderate 10-15% risk range is reasonable but not neglecting non-pharmacological lifestyle advice.

“In NZ there are more than 300,000 people now on regular statins which is approaching the number expected in the high risk categories. However, this number will include many people at relatively low risk who may receive little benefit and we are still far from detecting and treating all eligible high risk people.

“The aim of treatment for high risk individuals is to reduce absolute risk which in many cases may require a number of interventions.

“Whatever the risk level there appears to be the same relative risk reduction from treatment but the absolute risk reduction of course is less at lower levels.

“Take the example of a man in his 40s with an estimated “borderline” CVD risk of an event of say 10% over 5 years. This man has a 2% chance of a CV event each year over 5 years; a 98% chance of being event free year by year. With a statin the chance of an event might be reduced by about a third ie from 2% to say 1.3% each year; his chance of being event free being increased from 98% to 98.7% — what would the patient want?

“Although generally very well tolerated, statins are not without side effects and this is also an important consideration as use is extended.

“Monetary cost is not an issue now that statins are generic and they are highly cost effective when used in high risk groups.”

* Hay, D. 2004. cardiovascular Disease in New Zealand. 2004. A Summary of Recent Statistical Information. National Heart Foundation of New Zealand.