Heart Disease Risk: Which Blood Tests to Get

For decades, heart disease risk assessment relied almost entirely on the standard lipid panel: total cholesterol, LDL-C, HDL-C, and triglycerides. While these remain important, research over the past 15 years has revealed significant gaps. Roughly 50% of heart attacks occur in people with "normal" LDL cholesterol. Clearly, LDL-C alone doesn't tell the whole story.

The problem is that LDL-C measures the amount of cholesterol carried by LDL particles, not the number of particles themselves. Two people can have identical LDL-C values but very different particle counts — and it's the particle count that drives plaque formation. This is where advanced markers like ApoB come in.

A modern cardiac risk assessment should include:

• Standard Lipid Panel — still the foundation. Look at the full picture: LDL, HDL, triglycerides, and the TG/HDL ratio (ideally below 2.0).
• ApoB — one molecule of Apolipoprotein B sits on every atherogenic particle (LDL, VLDL, IDL, Lp(a)). ApoB directly counts dangerous particles.
• Lp(a) — a genetically determined, independent risk factor that standard panels miss entirely.
• hs-CRP — measures systemic inflammation, which is now recognized as a driver of atherosclerosis.
• Homocysteine — elevated levels damage the endothelial lining of arteries and increase clotting risk.
• HbA1c — diabetes and prediabetes dramatically accelerate atherosclerosis.

Together, these markers give you a far more accurate picture of cardiovascular risk than cholesterol alone.

Apolipoprotein B (ApoB) is increasingly recognized as the single best lipid marker for predicting cardiovascular events. Every atherogenic lipoprotein particle — LDL, VLDL, IDL, and Lp(a) — carries exactly one ApoB molecule. So ApoB gives you a direct count of all the particles that can enter your artery walls and form plaque.

Optimal ApoB is below 90 mg/dL for low-risk individuals and below 65 mg/dL for those at high risk. Some preventive cardiologists target below 60 mg/dL. If your LDL-C looks fine but your ApoB is elevated, you likely have a pattern of small, dense LDL particles — which are more dangerous per particle than large buoyant LDL.

Lipoprotein(a), or Lp(a), is a genetically determined variant of LDL that carries extra clotting risk. About 20% of the global population has elevated Lp(a), defined as above 50 nmol/L (or above 30 mg/dL, depending on the assay). Lp(a) is not meaningfully affected by diet, exercise, or statin therapy — it's essentially set by your genes.

Why does Lp(a) matter? It promotes plaque formation, inflammation, and blood clotting. Elevated Lp(a) roughly doubles your risk of heart attack and stroke independent of other risk factors. It's especially important to test if you have a family history of premature heart disease (heart attack before age 55 in a male relative or 65 in a female relative).

Lp(a) only needs to be measured once in your lifetime since it's genetically determined. If elevated, your doctor may manage other risk factors more aggressively and consider emerging therapies targeting Lp(a) directly.

Atherosclerosis is fundamentally an inflammatory disease. LDL particles that enter the artery wall trigger an immune response — white blood cells, cytokines, and foam cells create an inflamed, growing plaque. Measuring inflammation gives you a window into this process that lipid levels alone cannot.

High-sensitivity C-Reactive Protein (hs-CRP) is the most validated inflammatory marker for cardiovascular risk. It's produced by the liver in response to systemic inflammation. The American Heart Association defines risk categories as:

• Below 1.0 mg/L — low cardiovascular risk
• 1.0–3.0 mg/L — moderate risk
• Above 3.0 mg/L — high risk

The JUPITER trial demonstrated that patients with elevated hs-CRP (above 2.0 mg/L) but normal LDL cholesterol still benefited significantly from statin therapy — reducing heart attacks by 54%. This changed how we think about who needs treatment.

Homocysteine is an amino acid that, when elevated (above 12 µmol/L), damages the endothelial lining of blood vessels and promotes clotting. Elevated homocysteine is often caused by deficiencies in B12, folate, or B6 — all of which are easily correctable. Normal homocysteine is below 10 µmol/L; optimal is below 8 µmol/L.

If your CRP is persistently elevated, discuss with your doctor whether the inflammation might be from a non-cardiac source (infection, autoimmune disease, obesity). Two tests drawn 2 weeks apart give the most reliable assessment.

The American Heart Association recommends cardiovascular risk screening starting at age 20, with lipid panels every 4–6 years for low-risk individuals. However, if you have risk factors — family history, obesity, smoking, diabetes, high blood pressure, or elevated inflammatory markers — more frequent testing is warranted.

Recommended screening intervals:

• Lipid panel: Every 1–2 years if you have any risk factors; every 4–6 years if low-risk.
• ApoB: Annually if being treated for dyslipidemia; every 2–3 years otherwise.
• Lp(a): Once in a lifetime — it doesn't change meaningfully over time.
• hs-CRP: Every 1–2 years. Two measurements 2 weeks apart give the most reliable baseline.
• Homocysteine: At baseline; recheck 2–3 months after starting B-vitamin supplementation if elevated.
• HbA1c: Annually if you have any metabolic risk factors.

Preparation: A 9–12 hour fast is ideal for the most accurate lipid panel and glucose results. Avoid intense exercise for 24 hours before the draw, as it can transiently affect CRP. Blood can be drawn any time of day for Lp(a) and ApoB.

If you're starting a statin or other lipid-lowering therapy, recheck your lipid panel and ApoB at 6–8 weeks to assess response. The goal is to see at least a 30–50% reduction in LDL-C and ApoB moving toward target.