Lipoprotein(a), or Lp(a), is a lipoprotein particle structurally similar to LDL but with an additional apolipoprotein(a) protein attached. This structure gives Lp(a) both atherogenic and prothrombotic properties, making elevated Lp(a) a potent cardiovascular risk factor.

Lp(a) is 80-90% genetically determined and largely resistant to lifestyle modification. About 20-25% of Australians have elevated Lp(a). This elevation carries substantially higher lifetime cardiovascular risk independent of traditional risk factors including LDL cholesterol.