General Medicine Cardiology Endocrinology A

LDL Cholesterol — Friedewald Equation

Calculates LDL from total cholesterol, HDL, and triglycerides. LDL = TC − HDL − (TG / 2.2). Not valid if TG >4.5 mmol/L.

Score interpretation

Optimal LDL 0–1.7

LDL <1.8 mmol/L: Optimal (very high CV risk target)

→ Maintain if on high-intensity statin; no change needed

Near Optimal 1.8–2.5

LDL 1.8–2.5 mmol/L: Near optimal

→ Achieves ESC high-risk target; continue statin therapy

Above Optimal 2.6–3.3

LDL 2.6–3.3 mmol/L: Above optimal

→ Review cardiovascular risk; consider statin if primary prevention with 10-year risk >10%

Borderline High 3.4–4.1

LDL 3.4–4.1 mmol/L: Borderline high

→ Lifestyle modification; statin therapy strongly recommended for moderate–high CV risk

High LDL 4.2–99

LDL ≥4.2 mmol/L: High

→ High-intensity statin (atorvastatin 40–80 mg); consider ezetimibe or PCSK9 inhibitor if target not achieved; FH screening if LDL >5 mmol/L

Interpretation bands for the LDL Friedewald. Apply clinical judgement and local guidance.

Friedewald WT, Levy RI, Fredrickson DS. Estimation of the concentration of low-density lipoprotein cholesterol in plasma. Clin Chem. 1972;18(6):499-502.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Pathways

Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.