There is nothing more scandalous in the whole of medicine than a reliance on risk prediction algorithms as it can lead to a focus on risk rather than risk factors, says cardiologist and genetic epidemiologist Professor Brian Ference.
Professor Ference, from University of Cambridge in the United Kingdom, was speaking at a panel discussion on considerations for lipid guidelines at the Amgen One conference held in Melbourne.
The session was chaired by Professor Gerald Watts from Royal Perth Hospital, and panelists included Dr Garry Jennings, Executive Director of Sydney Health Partners, Associate Professor Karam Kostner from Mater Hospital, Brisbane, Professor Richard O’Brien, Chair of the Australian Diabetes Society’s Lipid Guidelines Committee, and Associate Professor David Sullivan, a member of the Royal College of Pathologists of Australasia.
According to Professor Ference there was a danger that algorithms could lead to a notion that physicians should treat risk rather than risk factors.
“To rely on a risk prediction algorithm dominated mathematically by age has the practical effect of inviting us to wait until somebody has sufficiently developed enough atherosclerotic burden that suddenly they’re at risk of a short-term event. That is a non-sensical way to practice medicine because we know precisely what causes atherosclerosis,” he said.
He explained that updated ESC guidelines on cardiovascular disease prevention (due in 2021) “will introduce an entirely new paradigm to how we think about preventive medicine, based on the notion that the risk of disease and the benefit of risk factor intervention is not determined simply by the magnitude of LDL-cholesterol and blood pressure reduction, but the duration of therapy.”
Recommendations in the 2012 Australian lipid management guidelines1 for secondary prevention suggests that evidence on absolute risk is from age 45 years and risk factors in younger patients do not need to be assessed. However, according to panel member Associate Professor David Sullivan this approach ‘completely paralyses’ efforts to detect conditions such as familial hypercholesterolaemia.
Doctor Garry Jennings agreed that patients younger than 45 years and at risk of cardiovascular disease due to clinical factors were not adequately considered in current algorithm-based treatment decisions. But waiting until age 45 before treating these patients may be too late: “If you have risk factors, you have irreversible vascular vessel damage by that time. We need to find a way to be much more inclusive in terms of application of risk assessment.”
Coronary Artery Calcium Scoring has a role but lacks strong evidence
Moving on to discuss coronary artery calcium scoring, the panel agreed that there was still a low evidence base to support its use for risk assessment. Associate Professor David Sullivan pointed out that, although it may be helpful in selecting high-risk patients for treatment, it’s still not well-understood how calcium scores evolved once patients were on appropriate treatment. Despite its shortcomings, many clinicians in the room considered that coronary artery calcium scoring and imaging studies could be very useful in identifying patients for primary prevention, and also for engaging patients in a discussion on why treatment would be beneficial.
Non-HDL cholesterol: a better primary marker for patient assessment
Associate Professor David Sullivan reminded delegates that apolipoprotein B (apo B) remained the best routinely available test available to measure particle numbers but was currently not covered by Medicare. Until such time as apo B testing becomes less costly to patients, “Please adopt non-HDL cholesterol as the primary marker of patient assessment, rather than LDL-cholesterol,” he advised.
This article was sponsored by Amgen, which has no control over editorial content. The content is entirely independent and based on published studies and experts’ opinions, the views expressed are not necessarily those of Amgen.
References
- Heart Foundation: Reducing risk in heart disease: An expert guide to clinical practice for secondary prevention of coronary heart disease; published 2012.