Non-HDL cholesterol could predict which people with ischaemic heart disease (atherosclerosis of the coronary arteries) and well-controlled LDL cholesterol have an increased risk of heart attack, stroke or death. A researcher says that this can determine who may benefit from intensified preventive treatment.
Statins are one of the most widely used and effective treatments for lowering LDL cholesterol and are the mainstay in secondary prevention of cardiovascular disease.
Nevertheless, some people with ischaemic heart disease and well-controlled LDL cholesterol still experience heart attack or a stroke.
A new study from Denmark shows how to identify people with ischaemic heart disease and well-controlled LDL cholesterol who have an increased risk of cardiovascular events.
The discovery has very obvious clinical potential, since doctors could identify people who may need additional cholesterol-lowering or other preventive drug treatment to reduce any increased cardiovascular event risk even further.
“Non-HDL cholesterol is not routinely reported in the laboratory chart, although it can easily be calculated from a standard lipid panel. The idea behind this study was that non-HDL cholesterol might be able to identify people who still have increased cardiovascular event risk despite having well-controlled LDL cholesterol,” explains a researcher behind the study, Malene Kærslund Hansen, doctor and PhD Fellow, Department of Clinical Medicine, Aarhus University, Denmark.
The research has been published in The Lancet Regional Health – Europe.
Non-HDL cholesterol levels for more than 23,000 people
The researchers aimed to investigate whether non-HDL cholesterol is associated with cardiovascular event risk among people with ischaemic heart disease and well-controlled LDL cholesterol. Non-HDL cholesterol means total cholesterol minus HDL cholesterol.
They obtained data from the Western Denmark Heart Registry, the Laboratory Information System, the Danish National Patient Registry and the Civil Registration System for 23,641 people who had undergone coronary angiography because of ischaemic heart disease from 2011 to 2020 and had well-controlled LDL cholesterol (≤1.8 mmol/L) within the first year afterwards.
The researchers divided the cohort into percentiles according to their non-HDL cholesterol and compared the cardiovascular event risk – the four-year risk of heart attack, stroke or death – between the 5% with the highest levels of non-HDL cholesterol and the 25% with the lowest levels.
Noticeably higher risk of heart attack, stroke and death
The comparison showed very clearly that measuring non-HDL cholesterol can indicate who has increased risk of experiencing heart attack, stroke or death.
The 5% of the cohort with the highest non-HDL cholesterol had an 80% higher risk of heart attack or stroke than the 25% of the cohort with the lowest non-HDL cholesterol.
The study also showed that people with the highest non-HDL cholesterol had a 70% higher risk of heart attack and 40% higher risk of death.
Malene Kærslund Hansen notes that these increases in risk are very large.
“The association for high versus low non-HDL cholesterol among people with ischaemic heart disease and well-controlled LDL cholesterol is the same as or stronger than the risk factors of diabetes and smoking. This is a very strong result,” she says.
Some people might benefit from additional treatment
Malene Kærslund Hansen thinks that the study indicates that measuring non-HDL cholesterol may improve the decision basis when doctors advise people with ischaemic heart disease about preventive treatment.
Doctors may enhance preventive drug treatment for those with elevated non-HDL cholesterol despite well-controlled LDL cholesterol.
Note that treatment for LDL cholesterol also lowers remnant cholesterol – the other component of non-HDL cholesterol.
There may also be other ways to treat people with ischaemic heart disease and well-controlled LDL cholesterol with increased cardiovascular event risk, including treatment for high blood pressure or improving treatment for diabetes.
Malene Kærslund Hansen says that a higher percentage of the people with the highest levels of non-HDL cholesterol had high blood pressure and diabetes.
“But clinical research should naturally investigate whether treating people more intensively for their elevated non-HDL cholesterol lowers their risk of heart attack, stroke or death,” she concludes.
