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How Blood Tests Can Reveal Early Signs of Heart Disease

PBTT

Private Blood Tests Team

Clinical Team

29 Dec 202510 min read

Heart disease remains the leading cause of death in the United Kingdom, claiming approximately 160,000 lives each year. Yet many people are unaware they are at risk until they experience a heart attack or stroke. The tragedy is that heart disease often develops silently over decades, with damage accumulating long before symptoms appear.

The good news is that blood tests can reveal your cardiovascular risk years or even decades before a cardiac event. By identifying risk factors early, you can take action to protect your heart and potentially add years to your life.

Understanding Heart Disease Development

Heart disease typically develops through atherosclerosis — the gradual buildup of fatty plaques in artery walls. This process begins in childhood and progresses throughout life, influenced by genetics, lifestyle, and various risk factors.

The key stages include:

  • Endothelial damage — The inner lining of arteries becomes injured
  • Fatty streak formation — Cholesterol deposits begin accumulating
  • Plaque development — Deposits grow and harden over time
  • Plaque rupture — Unstable plaques can rupture, causing heart attacks or strokes
  • Blood tests can detect this process at various stages, allowing for intervention before catastrophic events occur.

    Essential Blood Tests for Heart Health

    ### Lipid Profile (Cholesterol Test)

    The lipid profile remains the cornerstone of cardiovascular risk assessment. It measures:

    Total Cholesterol:

    An overall measure of cholesterol in your blood. While useful as a screening tool, the individual components provide more meaningful information.

    LDL Cholesterol ("Bad" Cholesterol):

    Low-density lipoprotein carries cholesterol to artery walls, where it can accumulate and form plaques. Elevated LDL is one of the most significant risk factors for heart disease.

  • Optimal: Below 2.6 mmol/L
  • Near optimal: 2.6-3.3 mmol/L
  • Borderline high: 3.4-4.1 mmol/L
  • High: 4.1-4.9 mmol/L
  • Very high: Above 4.9 mmol/L
  • HDL Cholesterol ("Good" Cholesterol):

    High-density lipoprotein removes cholesterol from arteries and transports it back to the liver. Higher levels are protective.

  • Low (increased risk): Below 1.0 mmol/L (men) or 1.2 mmol/L (women)
  • Optimal: Above 1.6 mmol/L
  • Triglycerides:

    These fats circulate in the blood and contribute to arterial plaque formation. Elevated levels often accompany metabolic syndrome.

  • Normal: Below 1.7 mmol/L
  • Borderline high: 1.7-2.2 mmol/L
  • High: 2.3-5.6 mmol/L
  • Very high: Above 5.6 mmol/L
  • ### High-Sensitivity C-Reactive Protein (hs-CRP)

    Inflammation plays a crucial role in heart disease development. hs-CRP measures low-grade inflammation throughout the body and has emerged as an important cardiovascular risk marker.

    What hs-CRP reveals:

  • Arterial inflammation
  • Plaque instability
  • Overall cardiovascular risk
  • Risk categories:

  • Low risk: Below 1 mg/L
  • Moderate risk: 1-3 mg/L
  • High risk: Above 3 mg/L
  • Research shows that hs-CRP adds predictive value beyond traditional cholesterol testing. For more information about inflammation markers, read our overview of the C-reactive protein test.

    ### Blood Glucose and HbA1c

    Diabetes and prediabetes significantly increase heart disease risk. Even mildly elevated blood sugar damages blood vessels over time.

    Fasting Glucose:

  • Normal: Below 5.6 mmol/L
  • Prediabetes: 5.6-6.9 mmol/L
  • Diabetes: 7.0 mmol/L or above
  • HbA1c:

    Reflects average blood sugar over 2-3 months.

  • Normal: Below 42 mmol/mol (6.0%)
  • Prediabetes: 42-47 mmol/mol (6.0-6.4%)
  • Diabetes: 48 mmol/mol (6.5%) or above
  • For detailed information, read our guide to understanding the A1C blood test.

    ### Lipoprotein(a)

    Lipoprotein(a), or Lp(a), is a genetic risk factor for heart disease that many people have never heard of. Unlike other lipids, Lp(a) levels are largely determined by genetics and do not respond significantly to lifestyle changes.

    Why Lp(a) matters:

  • Elevated in approximately 20% of the population
  • Significantly increases heart attack and stroke risk
  • Often overlooked in standard testing
  • Knowing your level helps refine overall risk assessment
  • ### Apolipoprotein B (ApoB)

    ApoB is a protein found on all atherogenic (plaque-forming) lipoproteins. Some experts consider it a better predictor of cardiovascular risk than LDL cholesterol alone.

    Why ApoB is valuable:

  • Measures the actual number of harmful particles
  • May be more accurate in people with metabolic syndrome
  • Helps identify residual risk when LDL appears normal
  • ### Troponin

    Troponin is a protein released when heart muscle is damaged. While primarily used to diagnose heart attacks, high-sensitivity troponin testing can detect subclinical heart damage.

    What elevated troponin may indicate:

  • Recent heart muscle damage
  • Chronic heart strain
  • Increased future cardiac risk
  • ### Homocysteine

    Elevated homocysteine levels have been associated with increased cardiovascular risk. This amino acid can damage blood vessel walls when present in excess.

    Causes of elevated homocysteine:

  • Vitamin B12 deficiency
  • Folate deficiency
  • Genetic factors
  • Kidney disease
  • Who Should Have Heart Health Blood Tests?

    Consider cardiovascular blood testing if you:

  • Are over 40 (or over 30 with risk factors)
  • Have a family history of heart disease
  • Have high blood pressure
  • Are overweight or obese
  • Have diabetes or prediabetes
  • Smoke or formerly smoked
  • Lead a sedentary lifestyle
  • Want to establish baseline cardiovascular health
  • For comprehensive health assessment, cardiovascular markers are typically included in full health checks. Learn more about what's included in a comprehensive health check.

    Beyond Blood Tests: A Complete Picture

    While blood tests provide crucial information, they should be considered alongside:

  • Blood pressure measurements
  • Body mass index (BMI) and waist circumference
  • Family history
  • Lifestyle factors (smoking, diet, exercise)
  • Overall health history
  • Taking Action

    If blood tests reveal elevated cardiovascular risk, many interventions can help:

  • Dietary changes — Reduce saturated fat, increase fibre and plant foods
  • Exercise — Regular physical activity improves nearly all cardiac markers
  • Weight management — Even modest weight loss improves risk factors
  • Smoking cessation — The single most impactful change for smokers
  • Medications — When lifestyle changes are insufficient
  • Heart Health Testing in London

    At Private Blood Tests London, we offer comprehensive cardiovascular risk panels at our CQC-registered clinic in South Kensington. Our tests go beyond basic cholesterol to provide a complete picture of your heart health.

    Learn more about [cholesterol testing](/cholesterol-test) and explore our [comprehensive health screening packages](/health-screening) for complete cardiovascular assessment.

    Do not wait for symptoms to appear. Book your heart health blood test today and take control of your cardiovascular future.

    Ready to Book Your Test?

    Visit our CQC-registered clinic in South Kensington for professional blood testing services.