Why Doctors Rarely Test Lipoprotein(a)
Physicians infrequently order Lp(a) testing primarily due to lack of familiarity with the marker, concerns about insurance coverage, absence of proven Lp(a)-specific therapies, and insufficient awareness of clinical guidelines—despite strong evidence that elevated Lp(a) is a powerful, heritable cardiovascular risk factor. 1, 2
The Core Barriers to Testing
Knowledge Gaps Among Physicians
The most significant barrier is lack of familiarity with Lp(a) itself. Survey data from major academic health systems reveals that:
- Only 31% of Internal Medicine and Cardiology providers regularly test for Lp(a) 1
- 44% of specialists (33% cardiologists, 52% endocrinologists) never test for Lp(a) 2
- Among those who don't test, 33% rated their familiarity with Lp(a) as low 2
- Major knowledge gaps exist regarding prevalence, pathophysiology, and clinical significance, with correct responses to knowledge questions being less than 30% 2
Perceived Lack of Treatment Options
The absence of FDA-approved Lp(a)-specific therapies is the most commonly cited barrier (59% of non-testing physicians) 2. This creates a therapeutic nihilism where physicians question the value of testing for something they cannot directly treat. However, this reasoning is flawed because:
- Elevated Lp(a) should trigger more intensive management of modifiable risk factors, particularly LDL cholesterol 3
- Niacin and LDL apheresis can lower Lp(a) in selected high-risk patients 3
- Novel Lp(a)-lowering therapies are in advanced clinical trials 3
Insurance and Billing Concerns
Physicians cite insurance/billing concerns as a significant barrier 1. Compounding this problem:
- No specific ICD-10 code exists for elevated Lp(a) in the United States 4
- Clinicians must use generic hypercholesterolemia codes, which inadequately capture the diagnosis
- This limits both clinical documentation and research using electronic health records 4
Low Testing Rates in Real-World Practice
The actual prevalence of testing is strikingly low:
- Only 0.3% of adults in a large University of California health system had Lp(a) testing over a 10-year period (2012-2021) 5
- Even among high-risk populations, testing remains rare:
What Guidelines Actually Recommend
Guidelines clearly support testing in specific high-risk populations, contradicting the low testing rates:
European Society of Cardiology/European Atherosclerosis Society (Class IIa, Level C) 4:
- Premature CVD
- Familial hypercholesterolemia
- Family history of premature CVD or elevated Lp(a)
- Recurrent CVD despite optimal lipid-lowering therapy
- ≥5% 10-year risk of fatal CVD
Broader Recommendations 3:
- Patients with intermediate cardiovascular risk (to reclassify into higher risk category if Lp(a) >50 mg/dL)
- Recurrent or rapidly progressive vascular disease despite lipid-lowering medication
- Patients with genetic dyslipidemia, low HDL-C, diabetes, or autoimmune diseases
- Hemodialysis patients and those with renal disease (Lp(a) is 2-3 fold elevated in these populations)
2026 ACC/AHA Guidelines 7:
The most recent guidelines specifically address evaluation and management of elevated Lp(a), signaling increased recognition of its importance.
Technical and Standardization Issues
An additional barrier is lack of reliable standardization across laboratories:
- No reliable universal cut-off value exists for CAD risk assessment 3
- Each laboratory may use its own reference values 3
- Conversion between mass (mg/dL) and molar (nmol/L) concentrations is problematic due to apo(a) size heterogeneity 3
- Most commonly used thresholds are >30 mg/dL or >50 mg/dL, though these vary by population 3, 4
However, progress is being made: A second-generation ISO-compliant reference measurement procedure based on quantitative mass spectrometry has been developed, with standardized reference materials now available 8.
Clinical Implications of Not Testing
The failure to test has real consequences:
- Elevated Lp(a) is associated with increased subsequent cardiovascular hospitalizations (hazard ratio 1.23-1.25 for Lp(a) >50 mg/dL) 6
- Patients with elevated Lp(a) who are tested show greater odds of subsequent lipid-lowering therapy initiation 6
- Lp(a) remains "invisible" to most patients and physicians, limiting access to appropriate preventive care 9
What Should Change
Education and training are considered the most useful interventions for improving care of patients with elevated Lp(a) 2. Specifically:
- Increase physician awareness that elevated Lp(a) is one of the strongest genetic risk factors for vascular disease 3
- Emphasize that finding elevated Lp(a) changes management: It should trigger intensive treatment of modifiable risk factors, especially LDL cholesterol 3
- Clarify that testing is recommended once in a lifetime for risk stratification, as Lp(a) levels are genetically determined and stable 3
- Advocate for an ICD-10 code for elevated Lp(a) to facilitate documentation and research 4
Common Pitfalls to Avoid
- Don't wait for Lp(a)-specific therapies before testing: The primary value is risk stratification and intensification of other modifiable risk factors
- Don't assume lifestyle modifications alone are sufficient: 25-38% of patients/caregivers report lifestyle changes as unsuccessful in managing overall CVD risk 9
- Don't test repeatedly: Lp(a) is genetically determined and remains stable throughout life; one measurement is sufficient 3
- Don't ignore elevated Lp(a) in patients achieving very low LDL-C: Patients with elevated Lp(a) are less likely to achieve target LDL-C because Lp(a)-cholesterol is included in the LDL-C measurement 4
The evidence is clear: physicians should be testing Lp(a) more frequently in guideline-recommended populations, but multiple systemic barriers—particularly knowledge gaps and perceived lack of treatment options—prevent appropriate implementation of existing guidelines.