This policy governs the medical necessity and coverage stance for various cardiovascular risk tests (e.g., CIMT, arterial compliance, advanced lipoprotein analysis, Lp-PLA2, multi-protein biomarker panels) for UnitedHealthcare Community Plan members in Kentucky.
Change TypeRevised coverage rationaleremoved select items from unproven list
Effective DateJun 1, 2025
Next Review Date
Key ActionRefer to plan prior authorization requirements and submitted codes; inclusion of codes in this policy is for reference only and does not guarantee coverage.
Coverage Rationale Revised list of unproven and not medically necessary services: Removed "long-chain omega-3 fatty acids as method to determine risk for cardiovascular disease"; Replaced related phrasing to reference Lp-PLA2 specifically; Updated list of examples of advanced lipoprotein analysis; removed "apolipoproteins"
Kentuckygeographic applicability
insufficient evidencecoverage rationale
>=50 mg/dLLp(a) risk threshold
15+codes listed
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2CPT codes removed
Coverage Criteria and Evidence Summary
Not medically necessary / Unproven
Listed tests are considered unproven and not medically necessary due to insufficient evidence demonstrating clinical utility or improvement in patient management or outcomes.
Unproven / Not Medically Necessary Tests: Carotid intima-media thickness (CIMT) measurement as an effective screening tool for management of cardiovascular disease; arterial compliance testing and waveform analysis (including pulse wave velocity and related central arterial pressure assessments); advanced lipoprotein analysis beyond standard fasting lipids (examples: lipoprotein(a) as a standalone risk-determination test, particle subfractions/particle size, LDL particle number/LDL-P); lipoprotein-associated phospholipase A2 (Lp-PLA2) enzyme testing as a method to determine risk for cardiovascular disease or ischemic stroke; endothelial function assessment (e.g., peripheral arterial tonometry [PAT], brachial artery flow‑mediated dilation) as a prognostic indicator to determine CVD risk; multi-protein diagnostic biomarker panels and algorithm-reported risk scores (including aptamer-based protein microarray analyses and listed 3‑, 4‑, and 7‑protein panels); other proprietary multi-protein algorithmic tests reported as risk scores; and related unlisted cardiovascular or vascular diagnostic services
Policy states inadequate evidence that use of these tests alters management or improves clinical outcomes; see referenced evidence summaries.
Evidence-based stance and criteria
Summary of evidence-based findings relevant to coverage decisions
Evidence conclusions: CIMT is associated with incident carotid plaque, stroke, and cardiovascular events in large observational cohorts and trial meta-analyses but provides only modest incremental risk reclassification over traditional risk factors and is outperformed by coronary artery calcium (CAC) in many studies. Advanced lipoprotein markers (including Lp(a) and apoB) show epidemiologic associations with ASCVD; elevated Lp(a) (eg, >90th percentile) is associated with higher MCE and CVD risk. Lp-PLA2 demonstrates associations with stroke and CHD in meta-analyses and cohorts, but overall evidence quality, assay heterogeneity, and lack of trials showing clinical utility limit its use. Proprietary multi-protein algorithmic panels report correlations or discriminatory performance in some studies but lack peer-reviewed evidence that use changes management or improves outcomes.
None of the cited studies demonstrate that integrating these measurements into clinical care improves patient outcomes; heterogeneity across studies and measurement methods is repeatedly noted.
Evidence summary / contexts where testing may be considered
Evidence synthesis and guideline-based contexts where testing may be considered or where evidence is insufficient:
Lp(a) evidence context: Large cohort analyses (eg, BiomarCaRE) show higher Lp(a) levels (eg, >90th percentile) are associated with increased major coronary events and CVD; observational data support Lp(a) as an independent, causal risk factor but studies do not demonstrate that measuring Lp(a) and acting on results improves outcomes.Lp(a) >90th percentile associated with higher risk
See BiomarCaRE and cohort studies for effect sizes and limitations.
Lp-PLA2 evidence context: Meta-analyses and cohort studies report modestly increased relative risks for stroke and CHD with higher Lp-PLA2 mass or activity, but low-quality evidence, variable assays, and inconsistent predictive performance mean clinical utility is unproven.elevated Lp-PLA2 associated with RR increases in meta-analyses
Studies do not show integration into care alters outcomes; further trials needed.
Covered when supported by guideline-based indications
Measurement of Lp(a), ApoB, CIMT, and other advanced tests may be considered or recommended in the following selected clinical situations (per cited specialty guidance):
Indications for Lp(a) measurement (select situations): Consider measuring Lp(a) at least once for risk stratification in: individuals with family history of premature ASCVD or known elevated Lp(a); all individuals with clinical ASCVD (especially premature or recurrent ASCVD despite LDL‑C lowering); persons of South Asian or African ancestry with relevant family history; patients with personal/family history of aortic valve stenosis; primary prevention individuals with 10‑year ASCVD risk >=10% when additional stratification may change management; and individuals with refractory LDL‑C elevations despite therapy.Clinical guidance notes risk-enhancing threshold >=50 mg/dL (ACC/AHA) and very high inherited levels >180 mg/dL (ESC/EAS)
Sources include AACE/ACE, ACC/AHA, ESC/EAS, and NLA statements.
Indications for apolipoprotein B (apoB) measurement: Measure apoB to aid risk assessment in select patients: those with diabetes, high triglycerides (relative indication when TG >=200 mg/dL), obesity, metabolic syndrome, very low LDL‑C, or established ASCVD where apoB may refine risk; apoB >=130 mg/dL is considered elevated and apoB <90 mg/dL may be a target for some higher‑risk individuals.apoB >=130 mg/dL considered elevated; TG >=200 mg/dL prompts consideration
Revised Unproven/Not Medically Necessary Services
Policy updates refining examples of advanced lipoprotein analysis and removal of certain items from the unproven/not medically necessary list:
Revised unproven services (summary of changes): Removed 'long‑chain omega‑3 fatty acids as a method to determine risk for cardiovascular disease' from the unproven/not medically necessary list; clarified prior language to reference lipoprotein‑associated phospholipase A2 (Lp‑PLA2) enzyme specifically as a method to determine risk for cardiovascular disease or ischemic stroke (removing broader language about other A2 phospholipases); updated examples of advanced lipoprotein analysis by removing 'apolipoproteins' from the examples; removed CPT codes 82172 and 84999 from applicable codes in this policy revision.
These are editorial/coverage‑list revisions recorded in the policy history; see Policy History/Revision Information and Instructions for Use for operational context.
The policy explicitly lists the following tests as unproven and not medically necessary due to insufficient evidence of clinical efficacy: carotid intima-media thickness (CIMT) measurement for screening/management of cardiovascular disease; arterial compliance testing/waveform analysis; advanced lipoprotein analysis (for example, Lp(a), lipoprotein subfractions or particle size); Lp-PLA2 enzyme testing; specified multi-protein diagnostic biomarker panels reported with algorithmic risk scores (including the 3-, 4-, and 7-protein panels listed); and endothelial function assessment methods such as peripheral arterial tonometry (PAT) or brachial artery ultrasound.
The document notes that the cited studies and meta-analyses document statistical associations but do not demonstrate how use of these tests changes care or improves outcomes. For example, systematic reviews and meta-analyses of CIMT found modest incremental reclassification versus traditional risk factors and did not address how CIMT measurement alters patient management; similarly, Lp-PLA2 studies are of low quality and do not show that integrating Lp-PLA2 measurement into clinical care improves outcomes.
Multi-protein blood tests that combine biomarkers with an algorithm (for example, HART CADhs and related proprietary panels) and peripheral endothelial function assessments (PAT or brachial artery flow-mediated methods) currently lack sufficient, high-quality peer-reviewed evidence of clinical utility. Existing studies report correlations or discriminatory performance but do not establish that these tests improve clinical decision-making or patient outcomes.
Routine use of advanced lipoprotein analyses (such as particle sizing or NMR-based lipoprotein profiling) and routine vascular function testing (arterial stiffness measures, peripheral endothelial function) for initial or population screening is discouraged. Guideline and society statements cited in the policy do not support routine ordering of these expanded lipid panels or vascular function tests as standard screening tools.
The policy identifies a set of specific services as unproven or not medically necessary and notes updates in this revision. The Summary of Changes documents removal of certain items (e.g., long-chain omega-3 fatty acids) and refinement of examples, and the list of unproven/not medically necessary services is the basis for exclusion from routine coverage.
Examples enumerated among the services considered unproven or not medically necessary include CIMT, arterial compliance testing/waveform analysis, advanced lipoprotein analysis (including Lp(a) and particle subfractions), Lp-PLA2, and peripheral endothelial function testing such as PAT or brachial artery ultrasound.
Pooled and meta-analytic evidence indicates that adding CIMT to traditional risk scores produces, at best, only small improvements in 10-year risk prediction. A meta-analysis of population cohorts found only a small improvement in 10-year risk prediction when CIMT was added to the Framingham Risk Score, and other systematic reviews concluded that CIMT offers modest incremental discrimination compared with coronary artery calcium (CAC) scoring; these differences are unlikely to be of clear clinical importance.
The routine application of multi-protein algorithmic risk scores and peripheral endothelial function testing for community screening or to guide management is not supported by the available evidence. Reviews and evidence summaries identify correlations between scores or endothelial measures and outcomes, but current literature does not demonstrate clinical utility sufficient to recommend routine use for screening or to direct therapy.
Measurement of advanced lipoprotein parameters beyond a standard fasting lipid profile for routine initial cardiovascular risk assessment in asymptomatic adults is discouraged. Studies report inconsistent incremental benefit of advanced lipoprotein testing over conventional risk factors, and society guidance recommends against routine ordering of expanded lipid panels for screening.
Following the revision, Lp-PLA2 is explicitly listed among services categorized as unproven or not medically necessary as a method to determine cardiovascular or ischemic stroke risk. The policy states that evidence quality for Lp-PLA2 is low and insufficient to establish clinical utility.
Procedure and Billing Codes
Referenced CPT/HCPCS/PLA codesmixed
0019M
Cardiovascular disease, plasma, analysis of protein biomarkers by aptamer-based microarray and algorithm reported as 4-year likelihood of coronary event in high-risk populations.
0052U
Lipoprotein, blood, high resolution fractionation and quantitation of lipoproteins, including all five major lipoprotein classes and subclasses of HDL, LDL, and VLDL by vertical auto profile ultracentrifugation.
0308U
Adiponectin and kidney injury molecule-1 (KIM-1) with 3 clinical parameters (age, sex, history of cardiac intervention), plasma, algorithm reported as a risk score for obstructive CAD.
0309U
Analysis of 4 proteins (NT-proBNP, osteopontin, TIMP-1, and KIM-1), plasma, algorithm reported as a risk score for major adverse cardiac event.
0377U
Cardiovascular disease, quantification of advanced serum or plasma lipoprotein profile; by NMR spectrometry with report of a lipoprotein profile (including 23 variables).
0415U
IL-16, FAS, FASLigand, HGF, CTACK, EOTAXIN, MCP-3 by immunoassay combined with clinical factors, blood, algorithm reported as a 5-year score for acute coronary syndrome.
Lipoprotein, blood; high resolution fractionation and quantitation of lipoproteins including lipoprotein subclasses when performed.
83704
Lipoprotein; blood; quantitation of lipoprotein particle number(s) (e.g., by NMR).
1–10 of 14
1/2
Regulatory / device referencesmixed
No codes listed
Removed/Updated CPT CodesCPT
82172
CPT code removed from applicable codes
84999
CPT code removed from applicable codes
cfPWV cut-off points evaluated
cfPWV cut-off points evaluatedClosest cut-off points to the summary were 10.7 m/s (predicting cardiovascular mortality) and 11.5 m/s (predicting all‑cause mortality).
Study scopeSystematic review/meta‑analysis included 9 studies (n=3,170) measuring carotid‑femoral PWV (cfPWV).
Lp(a) abnormal threshold
Lp(a) abnormal threshold (ATTICA)50 mg/dL used to define abnormal Lp(a) status in the ATTICA cohort; participants with Lp(a) ≥50 mg/dL had higher 10‑year CVD event rates.
Prior Authorization, Documentation, and Billing Guidance
Billing Rule
Coding and Documentation Note
The following code and documentation guidance is provided for reference only. Listing of codes does not imply coverage or reimbursement; verify federal, state, or contractual benefit plan requirements before submission. Providers should reference appropriate procedure and diagnosis codes on claims and include supporting clinical documentation to justify medical necessity.
Applicable codes listed in this policy are for reference only and may not be all inclusive.
Inclusion of a code does not guarantee coverage or payment; other policies and benefit plan terms apply.
Note
FDA Clearance Informational
FDA clearance or manufacturer claims are informational only. FDA approval or 510(k) clearance of a device does not by itself determine coverage. Providers should not rely solely on FDA clearance when determining medical necessity.
Background and Scope
This policy revision is effective 06/01/2025 and includes a material change: the policy version CSO1SKY.08 was archived and the Coverage Rationale was revised to update the list of unproven/not medically necessary services and to remove CPT codes 82172 and 84999 from the applicable codes. Users should verify federal, state, and contractual benefit requirements when applying the policy.
CIMT definitionCarotid intima‑media thickness (CIMT) is a noninvasive ultrasound measurement of carotid artery wall (intima and media) thickness used as a surrogate marker of subclinical atherosclerosis.
Measurement sitesCommon carotid artery (CCA) measurements reported as mean or maximum CCA‑IMT; studies vary in reporting conventions.
Clinical use noteSome guidelines support selective use of CIMT to refine risk stratification in selected intermediate‑risk adults, but routine measurement for initial risk assessment is not generally recommended.
Arterial compliance — methods
Arterial compliance / stiffness methodsArterial compliance and stiffness are assessed by methods such as pulse wave velocity (PWV), augmentation index, and blood‑pressure waveform analysis (including pulse wave analysis).
Policy Updates and Change Log
2025-06-01policy_revisionLatest
Revised list of unproven and not medically necessary services: removed long-chain omega-3 fatty acids as a risk-determination method; refined wording to reference Lp-PLA2 specifically; removed apolipoproteins from examples of advanced lipoprotein analysis; removed CPT codes 82172 and 84999 from applicable codes and archived prior version CSO1SKY.08.
2024-?evidence_update
BiomarCaRE pooled cohort evidence (Waldeyer et al.) reporting associations between elevated Lp(a) (>90th percentile) and increased major coronary events and CVD was incorporated into evidence summary.
Change TypeRevised coverage rationaleremoved select items from unproven list
Effective DateJun 1, 2025
Next Review Date
Key ActionRefer to plan prior authorization requirements and submitted codes; inclusion of codes in this policy is for reference only and does not guarantee coverage.
Systematic reviews and large meta-analyses find associations between baseline CIMT or CIMT progression and future CVD events, but incremental improvement in 10‑year risk prediction is small and unlikely to be clinically important; CAC generally provides superior discrimination compared with CIMT.
small net reclassification improvement for CIMT vs Framingham/CAC
Heterogeneity in CIMT definitions and measurement methods limits generalizability.
Multi-protein algorithm and endothelial function context: Some studies report reasonable discrimination for proprietary multi-protein panels or endothelial function measures, but systematic reviews (eg, Hayes on HART CADhs) and overall literature find insufficient peer-reviewed evidence of clinical utility to support routine clinical use for screening or management.example reported AUCs in individual studies but lacking external validation
Evidence gaps include lack of prospective outcome studies showing impact on management or outcomes.
Guidance from ACC/AHA, ESC/EAS, AACE, and NLA supports selective use.
Selective CIMT use: Some guidelines indicate CIMT may be reasonable in selected intermediate‑risk, asymptomatic adults to refine risk stratification, but CIMT is not recommended for routine initial CVD risk assessment and has limited incremental value compared with CAC or plaque detection.
ACC/AHA guidance discourages routine use; selective use per specialty guidance may be acceptable.
Advanced lipoprotein testing: Advanced lipoprotein tests (eg, particle number, small dense LDL, remnant cholesterol) are not recommended for routine screening but may be considered after initial evaluation in select patients where standard testing is insufficient; lack of assay standardization and outcome data limit broad recommendations.
Recommendations summarized from ESC/EAS, NLA, and ASCP statements.
Lp(a) percentile thresholds
Other large cohorts (BiomarCaRE) reported elevated risk for Lp(a) levels above the 90th percentile and in the 67–89th percentile range.
Study populationsATTICA: community cohort (n≈1,890 with baseline Lp[a]); BiomarCaRE: pooled 56,804 participants across 7 cohorts showing highest events >90th percentile.
CIMT cutoff used in CAD diagnostic subgroup
CIMT cutoff in CAD diagnostic subgroupA subgroup analysis reported a specific CIMT cutoff that yielded better diagnostic accuracy for CAD, but the exact millimeter value was not clearly stated in the report summary.
Overall diagnostic performancePooled sensitivity 0.68 and specificity 0.70 for IMT diagnosing CAD; AUC 0.74 overall, with subgroup AUC up to 0.80 for the unspecified cutoff value.
Study scopeMeta‑analysis of 22 articles evaluating IMT as a diagnostic method for CAD; noted heterogeneity across studies and limitations in reporting exact cutoffs.
Lp(a) risk thresholds
Lp(a) risk-enhancing threshold (ACC/AHA)>= 50 mg/dL (>=125 nmol/L) is identified as a risk‑enhancing factor for clinician–patient risk discussion.
Lp(a) very high inherited level (ESC/EAS)>180 mg/dL (>430 nmol/L) denotes very high inherited Lp(a) associated with lifetime ASCVD risk comparable to heterozygous familial hypercholesterolemia.
Percentile-based riskCohort analyses (BiomarCaRE) show increased MCE/CVD risk at >90th percentile compared with lower levels.
Apolipoprotein B (apoB) threshold
ApoB elevated threshold>=130 mg/dL is considered elevated and a risk‑enhancing factor per ACC/AHA guidance.
ApoB optimal goal for some high‑risk individualsAn optimal apoB goal of <90 mg/dL is recommended for certain individuals at increased ASCVD risk (AACE guidance).
Clinical contexts for measurementApoB measurement is advised for individuals with diabetes, obesity, metabolic syndrome, very low LDL‑C, or established ASCVD to refine risk assessment.
Triglyceride level relevant to apoB
Triglyceride level prompting apoB considerationA relative indication for apoB measurement is present when triglycerides are >= 200 mg/dL (per ACC/AHA guidance).
RationaleElevated triglycerides may obscure atherogenic particle burden; apoB can better reflect particle number in these settings.
Associated recommendationsGuidelines suggest apoB measurement in high TG or metabolic risk states to improve risk stratification.
Not applicable
Not applicableNot applicable.
ContextPlaceholder inventory entry — no threshold or value applicable for this item in the policy extract.
ReferencesSee policy reference list for underlying studies and guidelines cited elsewhere in the policy document.
EndoPAT 2000 (K032519) and predicate devices are listed as examples; device clearances are informational only.
SphygmoCor systems have received 510(k) clearances; clearance alone is not a basis for coverage.
Denial Risk
Potential Denial Triggers — Unproven Tests
Several tests and procedures are considered unproven or not medically necessary due to insufficient evidence of clinical utility. Ordering these tests may lead to claim denials if not supported by documented medical necessity.
Unproven/not medically necessary services include CIMT, arterial compliance/waveform analysis, advanced lipoprotein analysis (including particle size/subfractions), Lp-PLA2 testing, multi-protein algorithm risk tests, endothelial function assessment (PAT), aptamer-based protein microarray panels, and specified multi-protein panels.
Removal of certain CPT codes from the policy (e.g., 82172, 84999) may increase denial risk for services tied to removed codes.
Prior Authorization
No Explicit Prior Authorization Specified
This policy does not specify routine prior authorization requirements for the listed tests. Prior authorization requirements, if any, are determined by the member's benefit plan, state, or federal rules and by UnitedHealthcare utilization review processes (InterQual or UHC guidelines).
No explicit prior authorization requirement is stated in this policy for the services listed.
If InterQual or separate UHC Utilization Review Guidelines apply, follow those processes for authorization.
Denial Risk
Lack of Sufficient Peer-Reviewed Evidence / Study Limitations
Evidence is insufficient or inconsistent to demonstrate that these tests reliably improve clinical management or patient outcomes. Limitations in current literature include heterogeneous measurement methods, variable study populations, short follow-up, and lack of trials showing that test results change management to improve outcomes.
Studies often vary in how measurements (e.g., CIMT, lipoprotein subfractions, Lp-PLA2) were performed, lack standardization, and use older equipment in long-term cohorts.
Many analyses identify associations but do not demonstrate that use of the test alters clinical decision-making or reduces CVD events.
Documentation Required
Limitations in Measurement Methods and Study Heterogeneity
There is documented limitation in measurement methods and study heterogeneity that affects interpretation and generalizability of results; providers should recognize these limitations when ordering or interpreting tests.
Examples include variation in CIMT definitions (mean vs maximum), differences in ultrasound techniques, and non-standardized assays for advanced lipoprotein testing.
Heterogeneity across studies and populations limits the ability to generalize findings to routine clinical practice.
Documentation Required
When to Document Indication for Lp(a) Testing
When ordering Lp(a) testing, document the clinical indication and rationale in the medical record. Appropriate contexts for measurement are supported by specialty guidance and may influence coverage determination.
Consider documenting family history of premature ASCVD or known increased Lp(a).
Document presence of clinical ASCVD, especially premature or recurrent ASCVD despite LDL-C lowering, or refractory LDL-C elevation despite therapy.
Document ancestry (e.g., South Asian or African) with family history of ASCVD, personal or family history of aortic valve stenosis, or a 10-year ASCVD risk ≥ 10% when ordering Lp(a).
Cascade screening of first-degree relatives may be appropriate when elevated Lp(a) is identified.
Denial Risk
Denial Risks for Removed / Unproven Services
Tests and services identified as unproven or not medically necessary in this policy — and services with removed or deprecated CPT codes — carry an increased risk of coverage denial. Provide thorough clinical documentation if proceeding with testing that the policy characterizes as unproven.
Examples of increased denial risk: CIMT, arterial compliance testing, advanced lipoprotein analysis, Lp-PLA2 testing, multi-protein algorithm tests, and any services tied to CPT codes removed from the policy.
If a test is pursued despite policy listing, include detailed clinical justification, prior test results, and rationale for how results will change management.
Prior Authorization
Prior Authorization and Utilization Review Guidance
UnitedHealthcare uses InterQual for primary medical/surgical criteria; when InterQual lacks applicable criteria, UnitedHealthcare Medical Policies, Coverage Determination Guidelines, or Utilization Review Guidelines may be applied. Verify plan-specific utilization rules prior to ordering.
Follow InterQual criteria when available; if not available, follow applicable UHC policies or utilization review guidelines.
Check member's benefit plan and any state or federal requirements before ordering.
Documentation Required
Laboratory Quality and CLIA Standards
Laboratory testing for advanced lipoprotein analysis must meet Clinical Laboratory Improvement Amendments (CLIA) quality standards. Providers should ensure testing is performed in CLIA-certified laboratories.
Advanced lipoprotein analysis must be performed in accordance with CLIA quality standards.
Maintain documentation that testing was performed in a CLIA-certified laboratory when submitting claims.
Note
Check Plan and Criteria Before Applying Policy
Always verify federal, state, and contractual benefit plan requirements prior to applying this policy. In case of conflict, applicable federal, state, or contractual requirements govern coverage decisions.
This policy is informational and does not replace specific plan benefit language.
In the event of a conflict, federal, state, or contractual requirements for benefit plan coverage take precedence.
cfPWV specific
Carotid‑femoral PWV (cfPWV) is the commonly used measure for central arterial stiffness and was the focus of systematic review analyses in the policy.
Measurement considerationsNo universal standard exists for arterial compliance measurement; techniques and populations vary across studies, limiting comparability and clinical utility evidence.
Lp‑PLA2 definitionLipoprotein‑associated phospholipase A2 (Lp‑PLA2) is a vascular inflammatory enzyme evaluated as a biomarker for coronary heart disease and ischemic stroke risk; can be measured as mass or activity.
Evidence summaryMeta‑analyses and cohort studies report modest associations between higher Lp‑PLA2 levels and stroke/CHD risk, but evidence quality and assay heterogeneity limit conclusions about clinical utility.
Clinical utility noteCurrent evidence does not demonstrate that measuring Lp‑PLA2 improves management or outcomes; further well‑designed trials are needed.
Multi‑protein risk panels — definition
Multi‑protein risk panels — descriptionProprietary assays combining multiple protein biomarkers with algorithmic scoring (often using AI or machine learning) to produce a predicted risk score for obstructive CAD or future cardiovascular events (examples: HART CADhs, Prevencio tests).
Evidence stanceExisting studies report correlations and discriminatory performance for some panels, but systematic reviews and policy review conclude there is insufficient peer‑reviewed evidence of clinical utility to support routine use.
Regulatory/validation noteSome tests have internal validation or preliminary AUC/C‑statistic reports, but lack robust prospective outcome studies demonstrating impact on clinical management.
CIMT (alternate)
CIMT (alternate entry)Ultrasound measurement of the common carotid artery wall thickness used as a marker of subclinical atherosclerosis; reporting varies (mean vs maximum CCA‑IMT).
Role in risk stratificationMay refine risk assessment in selected intermediate‑risk patients per some guideline statements but not recommended for routine initial risk assessment by others.
Technical considerationsHigh‑quality technique, equipment, and operator training are required to achieve reliable results; heterogeneity in measurement limits comparability across studies.
Lipoprotein (a) — summary
Lipoprotein(a) summaryLipoprotein(a) is an LDL‑like particle containing apolipoprotein(a) and is associated with higher cardiovascular risk; elevated levels are linked to increased MACE and coronary disease severity in cohort studies.
Inherited natureLp(a) levels are largely genetically determined; guideline bodies recommend at least once in adult life measurement to identify very high inherited levels.
Risk thresholdsThresholds cited in policy include >=50 mg/dL as risk‑enhancing and >180 mg/dL as very high inherited level; cohort analyses report increased risk above the 90th percentile.
Lp‑PLA2 (alternate)
Lp‑PLA2 (alternate entry)An enzyme measured as mass or activity associated with increased risks of coronary heart disease and ischemic stroke in cohort studies and meta‑analyses, though assay heterogeneity and low quality evidence limit clear conclusions.
Predictive associationsMeta‑analysis reports relative risks for stroke and ischemic stroke ranging modestly above 1.0 for higher Lp‑PLA2 levels; results vary by activity vs mass measurements.
RecommendationPolicy notes that current evidence is insufficient to support Lp‑PLA2 as a clinical tool to guide management or improve outcomes.
Lipoprotein (a) — epidemiology
Lp(a) association with major eventsCohort analyses (e.g., BiomarCaRE, Waldeyer et al.) show higher Lp(a) associated with increased major coronary events (MCE) and CVD, particularly at or above the 90th percentile.
Magnitude of riskHazard ratios reported include ~1.30 for MCE and ~1.25 for CVD for Lp(a) in the 67–89th percentile, increasing further >90th percentile.
Clinical utility caveatStudies demonstrate association but do not establish that measuring Lp(a) in clinical practice improves outcomes; policy calls for context‑specific measurement per guidelines.
Multi‑protein blood test with algorithm
Multi‑protein panel with algorithm (example)Proprietary panels (e.g., HART CADhs, Prevencio tests) combine multiple protein biomarkers with an algorithmic score intended to predict obstructive CAD or short‑term cardiovascular risk.
Evidence limitationsHayes review and policy assessment found insufficient peer‑reviewed literature to conclude clinical utility for prediction of obstructive CAD or to guide management.
Clinical implicationAlthough some internal performance metrics are reported, absence of robust prospective studies showing impact on management limits coverage support.
Endothelial function assessment
Endothelial function assessment methodsNoninvasive assessments include peripheral arterial tonometry (PAT) and brachial artery flow‑mediated dilation (FMD) using ultrasound.
PurposeThese tests evaluate vascular endothelial function as a potential predictor of cardiovascular risk and early vascular dysfunction.
Evidence and limitationsMost studies show inconsistent associations with incident CVD or mortality; evidence insufficient to demonstrate clinical utility for routine risk stratification or to alter management.
Lipoprotein (a) — alternate
Lp(a) (alternate entry)An inherited LDL‑like lipoprotein with apolipoprotein(a); elevated Lp(a) is a causal, prevalent risk factor for ASCVD and is recommended for selective measurement in guideline statements.
Measurement frequencySome guidelines recommend at least one lifetime measurement to identify very high inherited levels (>180 mg/dL).
Population impactBiomarker and cohort data indicate substantial prevalence and association with MACE, supporting targeted testing in select clinical scenarios.
Apolipoprotein B (apoB)
Apolipoprotein B (apoB) — definitionApoB is a measure of atherogenic lipoprotein particle burden and is used to assess residual risk beyond LDL‑C.
Elevated threshold>=130 mg/dL is considered elevated and constitutes a risk‑enhancing factor per ACC/AHA guidance.
Clinical targetsAn optimal apoB target <90 mg/dL is recommended for some individuals at increased ASCVD risk (AACE guidance).
Carotid Intima‑Media Thickness (CIMT)
CIMT measurement descriptionCarotid intima‑media thickness is an ultrasound measurement of carotid artery wall thickness (intima + media) used as a marker of subclinical atherosclerosis and to refine risk estimates in selected patients.
Evidence summaryLarge meta‑analyses show associations between baseline CCA‑IMT and incident carotid plaque and CVD events, but incremental predictive value over traditional risk factors is modest.
Guideline guidanceSome organizations support selective use in intermediate‑risk asymptomatic adults; routine use for initial risk assessment is not generally recommended.
Lp(a) — additional note
Lp(a) additional noteLp(a) is genetically determined and recognized by guideline and society statements as a prevalent, causal risk factor warranting measurement in selected clinical contexts.
Guideline contextsConsider Lp(a) measurement for family history of premature ASCVD, clinical ASCVD (especially premature/recurrent despite LDL‑C lowering), high‑risk ancestries, aortic valve disease, or for reclassification in borderline risk individuals.
High‑risk threshold>180 mg/dL (>430 nmol/L) identifies very high inherited levels per ESC/EAS guidance.
Lp‑PLA2 — additional note
Lp‑PLA2 additional noteLp‑PLA2 is discussed as an enzyme biomarker associated with CHD and stroke in cohort studies and meta‑analyses, but policy language was updated to specifically reference Lp‑PLA2 and to reflect limited evidence for clinical utility.
Measurement formsLp‑PLA2 can be measured as mass or activity; results and associations vary by assay type and study methodology.
Policy positionGiven low‑quality and heterogeneous evidence, no conclusions support Lp‑PLA2 testing as an effective method to determine risk for CVD or ischemic stroke in routine practice.
2019-?
evidence_update
Meta-analyses and cohort data on Lp-PLA2 (including Hu et al. 2019) reporting associations with stroke were reviewed but judged low-quality and insufficient to support clinical utility.