THE fiery debate in Australia about the use of statins for the prevention of cardiac events sparked by the ABC’s Catalyst program has been reignited by the release of new guidelines by the American Heart Association. (1)
Released before the association’s 2013 Scientific Sessions last week, the 2013 ACC/AHA Guideline on the Assessment of Cardiovascular Risk includes a new absolute risk calculator which broadens the definition of who should be on statins and abandons recommended low-density lipoprotein (LDL) and non-high-density lipoprotein (HDL) cholesterol targets. (2)
The new calculator worried some US experts who protested about not only the broadening of the diagnostic guidelines, but also the backgrounds of those who wrote them. There were claims that several experts on the panel had recent or current financial ties to pharmaceutical companies, with added accusations that both the American Heart Association and the American College of Cardiology, while non-profit entities, were heavily supported by drug companies.
Writing in The New York Times, the two experts claimed that application of the new risk calculator, while eliminating the need for statins in people with isolated high LDL levels, would increase number of healthy people for whom the drugs were recommended by up to 70%. (3)
Dr Robert Grenfell, national cardiovascular health director at the Heart Foundation, and chair of the National Vascular Disease Prevention Alliance, told MJA InSight the brouhaha was a storm in a teacup, with the switch to an absolute risk calculator just the US catching up with the rest of the world.
“In Australia, we have had absolute risk guidelines for nearly 2 years”, Dr Grenfell told MJA InSight. “New Zealand has had them since 2002 and has seen a pleasing decrease in the progression of cardiac disease as a result.
“Absolute risk takes in a number of factors in calculating the likelihood of someone having a heart attack some time in the next 5 years. No calculator is perfect. Like any other assessment algorithm, it’s an aid and it is never meant to supplant clinical acumen”, he said.
Dr Scott Kinlay, associate professor of medicine at Harvard Medical School and director of intravascular ultrasound at Boston’s Brigham and Women’s Hospital, told MJA InSight the new guidelines were “a step in the right direction”.
“The majority of the debate concerns not those at high risk from clinically evident disease, but how we manage the large sector of the population at elevated risk but without obvious disease”, Dr Kinlay said.
Dr Kinlay said three of the four groups targeted by the new guidelines had good evidence for statin treatment — patients with clinically evident atherosclerotic cardiovascular disease (ACVD), those with diabetes and those with an LDL greater than 190 mg/dL (4.9 mmol/L).
He said the fourth group considered by the guidelines were those without ACVD and without diabetes, and whether statins were needed to manage risk in that group. “Here there is some controversy.”
The main critics of the guidelines were supporters of “no statin” therapy, on the basis that there is no evidence statins prevent death, Dr Kinlay said.
“In my view this is narrow-minded. ACVD is more than cardiac or stroke death. In fact, admissions with non-fatal myocardial infarction and stroke outweigh fatal events, and if you include coronary and vascular revascularisation, the non-fatal events clearly outnumber fatal events, contribute more to health care costs, and are equally, if not more, valued by patients as events worthy of prevention.
“Non-fatal events can have major effects on quality of life and health care costs, such as those incurred by chronic heart failure from a myocardial infarct, or disability from stroke.”
Dr Kinlay said the dilemma was where to draw the line with preventive medical treatment beyond lifestyle changes that everyone should adopt.
“The risk score in the new guidelines, like other risk scores around the world, tries to keep it simple and avoid too many measurements that could be done. It’s a reasonable choice”, he said.
1. ABC Catalyst 2013: Heart of the matter, 31 October
2. American Heart Association 2013; ACC/AHA Guideline on the assessment of cardiovascular risk: A report of the American College of Cardiology/American Heart Association task force on practice guidelines
3. New York Times 2013; Online 13 November