People with a genetic variant which increases blood levels of a cholesterol-like molecule called lipoprotein(a) have a higher risk of developing aortic valve stenosis, according to a new study led by researchers at the University of Oxford and McGill University, published in Circulation this week.

Aortic valve stenosis is a narrowing of the main valve in the outflow of the heart which, if untreated, results in heart failure and potentially death.

The Oxford-McGill team, together with other colleagues in the UK and Australia, used a technique called meta-analysis to combine the evidence from four previous studies of genetic variants for lipoprotein(a) and aortic valve stenosis, together with new results from the UK Biobank study.

The studies all investigated a genetic variant, known as rs10455872, which increases blood levels of lipoprotein(a). Each person can have zero, one, or two copies of this variant, and the more copies they have, the higher their blood level of lipoprotein(a) is likely to be.

The meta-analysis showed that overall, among almost 1800 aortic valve stenosis cases and 132,000 controls, each additional copy of rs10455872 was associated with a 66% higher risk of aortic valve stenosis.

The lead author Dr Ben Cairns, said, “This is the first study to confirm an association between any genetic variant and aortic valve stenosis. We can now have a high degree of confidence that an increased level of lipoprotein(a) is a cause of aortic valve stenosis.”

The findings may help to point the way to new treatments for the disease. New drugs are being developed to lower the level of lipoprotein(a) in the blood, and these drugs might also reduce the risk of aortic valve stenosis.