Methodology & Citations

Editorial principles

1. Calm, not casual. These tools are for the moment a lab result lands and the reader is anxious. Tone is direct and reassuring without minimizing real risk.
2. Guideline-anchored, not opinionated. Every threshold cites a specific peer-reviewed source or major society guideline. Where guidelines disagree, we say so.
3. Modern markers first. Where ApoB and Lp(a) are clinically relevant, we surface them — even when standard panels still center LDL.
4. Education, not medical advice. Every output ends with a clinician handoff. We do not recommend specific medications, dosages, or substitutions.

Primary guidelines used

• 2026 AHA/ACC Dyslipidemia Guidelines — primary US source. Formally incorporates ApoB measurement for treatment targets in adults on lipid-lowering therapy.
• 2021 ESC/EAS Guidelines for the Management of Dyslipidaemias — European reference. ApoB-prioritized risk assessment since 2019.
• 2021 Canadian Cardiovascular Society Lipid Guidelines — used for Lp(a) thresholds in nmol/L.
• 2018 ACC/AHA Cholesterol Clinical Practice Guidelines — risk-enhancer framework used in the CAC decision tool.
• USPSTF and SCCT statements on CAC scoring — appropriate-use thresholds for coronary artery calcium imaging.

Key cohort studies referenced

• CARDIA — Coronary Artery Risk Development in Young Adults. Source for the discordant-high-ApoB → 55% increased CAC risk finding cited in the discordance checker.
• SWAN — Study of Women's Health Across the Nation. Source for the 10–15% LDL rise across the menopause transition used in the perimenopause estimator.
• MESA — Multi-Ethnic Study of Atherosclerosis. Source for CAC percentile ranges by age and sex.
• Sniderman et al. — multiple meta-analyses on ApoB/LDL discordance thresholds and clinical outcomes.

Specific thresholds and how we set them

An honest disclosure: the American Heart Association does not publish a fixed cholesterol cutoff table in its current patient-facing materials. The AHA's official position is that "there isn't one 'normal' LDL level that works for everyone" — goals are individualized based on age, health history, diabetes, and overall cardiovascular risk. Where the AHA does publish a specific number, we use it. Where it does not, we cite the European Society of Cardiology (ESC/EAS 2021) or Canadian Cardiovascular Society (CCS 2021) — both of which the AHA references — and we label these clearly.

LDL (AHA-anchored)

Three AHA treatment-target tiers: <100 (general adult goal), <70 (high cardiovascular risk), <55 (very high risk / secondary prevention). Above-target bands (100–129, 130–159, 160–189, ≥190) follow the AHA's 2026 dyslipidemia guideline framework where a treatment conversation becomes increasingly warranted.

Triglycerides (AHA-anchored)

Below 150 mg/dL is "normal" per the AHA. Higher bands (150–199, 200–499, ≥500) follow ATP III conventions still referenced in AHA clinical materials, with ≥500 flagged for pancreatitis risk.

HDL (AHA position: not a treatment target)

The AHA explicitly states HDL is not a treatment target. We surface it as a risk marker only. Sex-specific low thresholds (<40 men, <50 women) come from ATP III. Very-high flag at >90 reflects emerging literature on paradoxical risk in some genetic profiles.

ApoB (AHA endorses measurement; ESC/CCS thresholds)

The AHA's 2026 guideline endorses ApoB measurement to refine residual risk — particularly for high triglycerides, metabolic syndrome, diabetes, or known cardiovascular disease — but does not publish numeric thresholds. The bands we use (<80, 80–99, 100–129, ≥130) come from ESC/EAS 2021 and CCS 2021, both referenced by the AHA.

Lp(a) (AHA-anchored)

≥125 nmol/L (50 mg/dL) is the AHA's elevated threshold, associated with ~1.4× increased long-term risk. ≥250 nmol/L (100 mg/dL) is the "doubled risk" threshold. The AHA recommends every adult be tested at least once in their lifetime. Conversion from mg/dL uses an approximate factor of 2.5; true conversion is isoform-dependent.

Non-HDL

Non-HDL targets generally track LDL targets + 30 mg/dL (e.g. non-HDL <130 corresponds to LDL <100). The 2026 AHA dyslipidemia guideline includes non-HDL as a treatment goal alongside LDL.

What these tools deliberately do NOT do

• Recommend specific medications, dosages, or starting/stopping therapy.
• Calculate a specific 10-year ASCVD risk score (use the ACC/AHA calculator for that — and discuss with a clinician).
• Diagnose familial hypercholesterolemia, metabolic syndrome, or any other condition.
• Replace a clinician who knows your full history.

Reviewer

Interpretation rules and copy across all four Hey Heart tools are reviewed by a board-certified clinician with a focus in preventive cardiology and lipidology. Reviewer credentials and last-review date will be listed here once retainer is finalized.

Updates

These tools are versioned. We update them when guidelines change (2026 AHA/ACC adoption was the most recent), when major new evidence lands (e.g. Lp(a)-targeted therapy trial readouts), or when reviewers flag a copy issue. Last update: 2026-05-06.