Volume 200 - Issue 3
Primary prevention of cardiovascular disease: new guidelines, technologies and therapies
Author: Constantine N Aroney
Med J Aust 2014; 200 (3): 146-148. || doi: 10.5694/mja13.11084
Published online: 17 February 2014
Published online: 17 February 2014
Does a formulaic approach based on traditional risk factors measure up?
To the Editor: In relying exclusively on traditional risk factors, Nelson and Doust have failed to provide an effective method of screening the asymptomatic individual for cardiovascular risk.1 Much of the population-attributable risk for myocardial infarction is related to these risk factors, but their specificity is very low because of their high prevalence in people who will never develop the disease. Like the general population, most individuals with coronary heart disease have one or no conventional risk factors.2
Although global risk scores are relevant in population studies, they are poorly predictive in the individual patient. In many studies, most hard coronary events (eg, coronary deaths and myocardial infarction) occur in people classified as low or intermediate risk, whereas most of those classified as high risk have no coronary events.3 Risk factor score assessment or serum cholesterol levels are inadequate for predicting individual coronary risk. An alternative is computed tomography coronary calcium scoring, a direct measure of coronary atheromatous burden. Although research on its utility is ongoing, a positive score is nearly 100% specific for coronary atheromatous burden, whereas a negative test has a 96%–100% negative predictive value for obstructive lesions.4 Most importantly, the score is highly predictive of risk, regardless of risk factors.4-6
Relying on traditional coronary risk factors, rather than a measure of coronary atheromatous burden, is like going back to a time when risk factors, rather than mammography, were used to determine breast cancer risk. Australian guideline recommendations need to develop new effective paradigms of risk assessment,6 and the Pharmaceutical Benefits Advisory Committee must alter its recommendations for statin use to include measures of coronary atheromatous burden. Until this happens, the Australian public will continue to be misled and a great opportunity for reducing coronary mortality will continue to be lost.
Competing interests
No relevant disclosures.
References
- Nelson MR, Doust JA. Primary prevention of cardiovascular disease: new guidelines, technologies and therapies. Med J Aust 2013; 198: 606-610. CHDDFAEE
- Khot UN, Khot MB, Bajzer CT, et al. Prevalence of conventional risk factors in patients with coronary heart disease. JAMA 2003; 290: 898-904. CBBGJGAI
- Akosah KO, Schaper A, Cogbill C, Schoenfeld P. Preventing myocardial infarction in the young adult in the first place: how do the National Cholesterol Education Panel III guidelines perform? J Am Coll Cardiol 2003; 41: 1475-1479. CBBHFHBE
- Krause RS. Cardiac tests. Computed tomography. Medscape 2013; 9 Dec. http://emedicine.medscape.com/article/811577-overview#aw2aab6b7 (accessed Jan 2014).
- Budoff MJ, Shaw LJ, Liu ST, et al. Long-term prognosis associated with coronary calcification: observations from a registry of 25,253 patients. J Am Coll Cardiol 2007; 49: 1860-1870.
- Aroney CN. A suggested paradigm for coronary risk screening in asymptomatic persons — assessment of total coronary atheromatous burden. Heart Lung Circ 2012; 21: 449-454. CBBEDEHJ