Risk Factor

* Population-Attributable Risk (% PAR)

Abnormal lipids

This is the main player – see below

49.2%

Smoking

Current or past tobacco/vaping use

35.7%

Psychosocial stress

Chronic stress, anxiety, or depression

32.5%

Abdominal obesity

BMI ≥25 or waist circumference >94 cm (men) or >80 cm (women)

20.1%

Hypertension

BP >140/90 mmHg (or >130/80 for high-risk groups)

17.9%

Low fruit and vegetable intake

Diet high in saturated fats, salt, or sugars

13.7%

Lack of regular physical activity

<150 min/week moderate exercise

12.2%

Diabetes

Diagnosed type 2 diabetes

9.9%

Alcohol (protective in moderation)

Drinking Level (Standard Drinks) #

Effect on CV Risk

Lipid Marker

Predictive Power

Comments

Normal Ranges

LDL-C

✅ Very Important

This is the main marker used unlesstriglycerides (TGs) are high (> 2 mmol/L) because high TG can artificially lower LDL.

Then it’s better to use Apo-B or Non-HDL-C.

Used for statin response monitoring.

Part of routine lipid panels.

Low risk patient <2.6 mmol/L

Moderate risk patient (10–15%) <2.0–2.5 mmol/L

High risk patient (CVD, diabetes) <1.8 mmol/L

V high risk patient (recent MI, stroke) <1.4 mmol/L

Non-HDL-C

✅ Strong predictor

Includes all atherogenic particles (LDL, VLDL, IDL, Lp(a)) – better than LDL-C in high TG states.

Used for statin response monitoring.

Part of routine lipid panels.

Low risk patient <3.4 mmol/L

Moderate risk patient <3.0 mmol/L

High risk patient (CVD, diabetes) <2.5 mmol/L

V high risk patient (recent MI, stroke) <2.0 mmol/L

Lipoprotein(a)

✅ Emerging strong risk marker

Independent genetic risk factor.

Increasingly recommended in patients with a family history of CVD.

NOT part of routine lipid panels.

One test per lifetime.

No Medicare rebate (fee ~ $77).

Not modifiable, just adds to risk profile.

Normal < 75 nmol/L

Borderline/possible risk 75 – 125 nmol/L

Increased CVD risk > 125 nmol/L

ApoB(Apolipoprotein B)

✅ Very strong

Reflects the number of atherogenic particles; superior to LDL-C in predicting CV events.

In patients with diabetes, metabolic syndrome, family history of CVD, or elevated TGs, ApoB is a more accurate indicator of atherogenic burden than LDL-C — and can change management decisions.

NOT part of routine lipid panels.

No Medicare rebate (fee ~ $25).

General population <1.0 g/L

High risk patient (CVD, diabetes, FHx) <0.8 g/L

Triglycerides (TG)

⚠️ Moderate

Modest independent risk predictor.

Prescription-strength Fish Oil (e.g., EPA 4 g/day) does lower TG, but does not necessarily reduce heart attack risk.

Part of routine lipid panels.

Mild-Mod Elevated 1.7-4.5 mmol/L

Severely Elevated > 5.6 mmol/L

HDL-C

❌ Weak/Unreliable

Historically thought protective, but raising HDL-C does not reduce CV risk; low HDL is a marker of risk, not a target.

Raising HDL-C artificially does not reduce CVD events — multiple trials have shown no benefit from HDL-raising agents (e.g., fish oil – omega 3)

Part of routine lipid panels.

Low – associated with increased risk:

<1.0 mmol/L (men)

<1.2 mmol/L (women)

Acceptable (depends on other risk factors):

1.0–1.5 mmol/L

Protective trend, but not a treatment target:

>1.5 mmol/L

Total cholesterol

❌ Less predictive

Useful only when subfractions are unavailable; lacks nuance.

Part of routine lipid panels.

Risk Level

Lifetime Risk (%)

is meaningful if < 45 Years

10-Year Risk (%)

best estimate if > 45 Years

but still useful if < 45 Years

Clinical Interpretation

Lifetime risk is meaningful especially where 10-year risk may be artificially low (aided by young age), but patient has risk factors such as smoking, family history, diabetes.

Lifetime risk becomes less useful — absolute 10-year risk guides treatment.

Low risk

<10%

Lifestyle advice only; no pharmacological intervention typically needed.

Moderate risk

10–20%

Consider treatment (e.g., statin, BP meds) based on shared decision-making and patient factors.

High risk

>39%

>20%

Strong indication for statins ± BP control and aggressive risk factor modification.

Question

Answer

Can CAC be repeated on statins?

❌ Not routinely

Does statin reduce CAC score?

❌ No – may increase it (helps plaques stabilise/calcify)

Does a higher CAC always mean worse disease?

❌ Not on statin

Best use of CAC?

✅ 1-time risk reclassification before starting statin

Monitoring Tool

Usefulness

LDL-C, non-HDL-C, ApoB

✅ Yes – track lipid-lowering effect

Blood pressure, glucose, BMI

✅ Yes – CV risk control

CAC score (repeat)

❌ No – not useful on statin

Requirement

Must be met?

Specialist/consultant referral

✅ Yes

Stable symptoms consistent with CAD

✅ Yes

Low to intermediate pre-test risk

✅ Yes

No known coronary artery disease

✅ Yes

Not done in past 5 years (unless new disease)

✅ Yes

Performed at Medicare-accredited facility

✅ Yes