Should You Order Lipoprotein(a) for Cardiovascular Risk Assessment?
Yes, measure lipoprotein(a) once in all adults as part of initial cardiovascular risk screening. The most recent and authoritative guideline—the 2021 Canadian Cardiovascular Society guidelines—provides a strong recommendation for universal, one-time Lp(a) measurement in all adults 1.
Who Should Be Tested
Universal screening approach:
- All adults should have Lp(a) measured once in their lifetime as part of initial lipid screening 1
- This represents a shift from older, more selective testing strategies to universal assessment
Priority populations (if universal testing not yet implemented): The 2020 Endocrine Society guidelines suggest measuring Lp(a) in adults with 2:
- Family history of premature atherosclerotic cardiovascular disease (men <55 years, women <65 years)
- Personal history of atherosclerotic cardiovascular disease
- Family history of elevated Lp(a)
The 2019 AHA/ACC guidelines identify Lp(a) as a "risk-enhancing factor" when deciding on statin therapy in intermediate-risk patients 3, 4.
Clinical Significance of Results
Elevated Lp(a) is defined as:
- ≥50 mg/dL or ≥125 nmol/L 2, 1, 4
- This threshold represents approximately the 80th percentile and confers significantly increased cardiovascular risk
Risk magnitude:
- Lp(a) levels >30 mg/dL show progressive increase in cardiovascular disease risk 5
- Levels >50 mg/dL enhance atherosclerotic cardiovascular disease risk substantially 2
- Approximately 20% of adults have elevated Lp(a) 1
Key Testing Principles
One-time measurement:
- Lp(a) levels are genetically determined and stable throughout adult life 2, 1, 5
- Repeat testing is not necessary once measured
- Levels are minimally influenced by lifestyle factors
Fasting not required:
- Lp(a) can be measured in non-fasting state
Clinical Management When Elevated
Lp(a) is not currently a treatment target 1, but finding elevated levels should trigger:
More intensive risk factor modification 1:
- Earlier and more aggressive health behavior counseling
- More intensive management of modifiable risk factors, particularly LDL-cholesterol
Enhanced LDL-cholesterol lowering 2:
- Consider intensifying LDL-lowering therapy
- In intermediate-risk primary prevention patients with elevated Lp(a), this may favor initiating statin therapy
- In secondary prevention, elevated Lp(a) predicts recurrent events and suggests need for intensified therapy, potentially including PCSK9 inhibitors
Consider coronary artery calcium scoring 3, 2:
- When risk assessment remains uncertain after finding elevated Lp(a)
- Helps refine treatment decisions in borderline or intermediate-risk patients
Important Caveats
No specific Lp(a)-lowering therapies currently approved:
- Statins and ezetimibe do not appreciably lower Lp(a) 1
- PCSK9 inhibitors lower Lp(a) by 20-30% but are not specifically indicated for this purpose
- Novel therapies (antisense oligonucleotides, siRNA) are in clinical trials 1
Measurement considerations:
- Assays should be calibrated to WHO/IFCC standards when possible 1
- Results reported in nmol/L are preferred over mg/dL due to variability in apolipoprotein(a) isoform size
Common pitfall: Elevated Lp(a) contributes to measured "LDL-cholesterol" but is not lowered by standard LDL-lowering therapies. This can create confusion when LDL-C appears elevated despite statin therapy.