High Lipoprotein(a): The Hidden Inherited Heart

What Is Lipoprotein(a) and Why Does It Matter?

Lipoprotein(a), abbreviated Lp(a), resembles LDL cholesterol but carries an additional protein called apolipoprotein(a). Genetic variants largely determine how much Lp(a) circulates in the blood, and levels usually remain relatively stable throughout adulthood. Diet and exercise remain essential for overall cardiovascular health, but they generally have much less influence on Lp(a) than they do on LDL cholesterol.

Multiple genetic, epidemiological and clinical studies support Lp(a) as a causal cardiovascular risk factor. High concentrations are associated with atherosclerotic cardiovascular disease and calcific aortic valve stenosis. The newly reported findings add to concerns that people with very high levels may face particularly elevated risks of stroke and cardiovascular death, although an individual's absolute risk also depends on age, blood pressure, smoking, diabetes, kidney health and other cholesterol measurements.

Who Should Be Tested for High Lipoprotein(a)?

A standard lipid panel does not necessarily include Lp(a), so it usually requires a separately ordered blood test. European guidelines recommend considering at least one measurement during adulthood. Testing is especially relevant for people with premature heart disease or stroke, familial hypercholesterolemia, recurrent cardiovascular events despite treatment, calcific aortic valve stenosis or a strong family history of early cardiovascular disease.

Laboratories may report Lp(a) in milligrams per deciliter or nanomoles per liter. These units describe different properties and cannot be converted accurately with one universal formula because particle composition varies among individuals. Clinical interpretation should therefore use the reported unit, the laboratory method and the patient's overall cardiovascular risk rather than treating Lp(a) as an isolated diagnosis.

What Can Patients Do If Their Lipoprotein(a) Is High?

People with elevated Lp(a) should not assume that a cardiovascular event is inevitable. Clinicians can reduce total risk by addressing LDL cholesterol, blood pressure, diabetes, smoking, physical inactivity and other modifiable factors. Statins do not specifically lower Lp(a), but they remain important when indicated because lowering LDL cholesterol reduces cardiovascular events. PCSK9-targeting medicines can produce modest reductions in Lp(a) while substantially lowering LDL cholesterol.

Several investigational therapies are designed to reduce production of apolipoprotein(a), including antisense and small-interfering RNA approaches. These agents can markedly lower Lp(a) in trials, but the crucial question is whether that reduction prevents heart attacks, strokes or cardiovascular deaths. Until cardiovascular-outcome trials provide definitive answers and regulators approve an indication, patients should avoid unproven supplements or treatments marketed specifically for Lp(a).