Cardiovascular disease, encompassing heart attacks, strokes, peripheral arterial disease, and heart failure, remains the leading cause of mortality and disability in the UK, responsible for approximately one in four deaths annually. This persists despite major advances in treatment, because the medical system is far better at managing established cardiovascular disease than preventing it. The tools for identifying who is at risk and intervening before the first event exist and are supported by evidence, but they are not deployed in standard clinical practice with anything approaching the systematic rigour that the scale of the problem warrants. Adults on the Isle of Man who want to genuinely understand their cardiovascular risk, not merely have it estimated from a simplified algorithm applied to standard blood test results, need an assessment that goes significantly beyond what primary care typically provides.
The Limitations of Standard Cardiovascular Risk Calculators
QRISK3 is the cardiovascular risk calculator used in NHS primary care to estimate the 10-year risk of a cardiovascular event. It incorporates age, sex, smoking, blood pressure, total cholesterol-to-HDL ratio, type 2 diabetes, deprivation score, and family history. It is a reasonable population-level tool but it misclassifies a substantial proportion of individuals at the individual level. It does not incorporate ApoB or LDL particle number, Lp(a), fasting insulin or HOMA-IR, inflammatory markers, cardiorespiratory fitness, or any functional measure. For people whose actual atherogenic risk differs significantly from what these simple parameters suggest, the calculator produces inaccurate risk estimates that lead either to over-treatment of low-risk individuals or, more dangerously, under-treatment of high-risk individuals.
A person with a normal total cholesterol-to-HDL ratio but a pattern of small, dense LDL particles, elevated Lp(a), and insulin resistance has substantially higher cardiovascular risk than QRISK3 would estimate, because none of these factors enter the calculation. Conversely, a person with moderately elevated total cholesterol but very high HDL, no insulin resistance, excellent cardiovascular fitness, and absent family history may have a far lower actual risk than a superficially similar cholesterol level suggests. The Longevity MOT approach to cardiovascular risk adds the specific biomarkers and functional measures that account for these individual differences.
ApoB: The Cardiovascular Biomarker You Need to Know
Apolipoprotein B is the structural protein on the surface of every atherogenic lipoprotein particle, including LDL, VLDL, IDL, and Lp(a). Each of these particles carries exactly one ApoB molecule, meaning that ApoB measurement directly counts the number of potentially atherogenic particles circulating in the blood. Atherosclerosis is initiated when atherogenic lipoproteins cross the arterial endothelium and become trapped in the intimal layer; the more particles there are, the greater the probability of this occurring at any given moment. This makes ApoB the most mechanistically direct measure of atherogenic risk available from a simple blood test, and multiple large prospective studies have confirmed its superiority over LDL cholesterol as a cardiovascular event predictor.
The discordance between LDL cholesterol and ApoB is most significant in people with insulin resistance, metabolic syndrome, or elevated triglycerides, who tend to have small, dense LDL particles that carry relatively little cholesterol per particle. Such individuals can have normal or near-normal LDL cholesterol concentrations while carrying a high number of atherogenic LDL particles, producing an apparently low-risk lipid profile that conceals a substantially elevated particle burden. ApoB testing costs approximately the same as standard LDL measurement and is available from most clinical laboratories, yet it is not included in standard NHS blood panels. Requesting it alongside standard lipids at your next blood test costs almost nothing; the information it provides may be clinically significant.
Coronary Artery Calcium Score: Seeing Atherosclerosis Directly
The coronary artery calcium score is a low-dose CT scan of the heart that quantifies calcified atherosclerotic plaque in the coronary arteries, expressed as a score on the Agatston scale. A CAC score of zero indicates no measurable coronary calcification and is associated with very low 10-year cardiovascular event risk, even in individuals with conventional risk factors. A CAC score above 300 indicates advanced atherosclerosis and substantially elevated event risk requiring aggressive risk factor management. The CAC score directly measures the accumulated burden of atherosclerotic disease in the coronary arteries, providing biological evidence of arterial damage that risk calculators can only estimate.
Research by Blaha and colleagues examining CAC scoring in individuals with intermediate QRISK3 estimates, where the calculator can most accurately guide treatment decisions, found that the CAC score reclassified a significant proportion of patients to either higher or lower risk categories than the algorithm suggested, with direct implications for treatment decisions. For adults on the Isle of Man in their 40s or 50s who want to understand whether years of suboptimal lifestyle have already produced measurable coronary arterial changes, a CAC scan provides this biological reality check. A zero score offers genuine reassurance; an elevated score provides the motivation and clinical justification for intensive lifestyle and potentially pharmacological intervention.
Cardiorespiratory Fitness: The Forgotten Vital Sign
VO2max, the maximum rate at which the cardiovascular and respiratory systems can deliver oxygen to working muscles, is the most powerful single predictor of all-cause mortality available. The evidence for this is overwhelming: the data from Kokkinos and colleagues' 2022 JAMA Network Open study of over 750,000 participants found that cardiorespiratory fitness was a better predictor of mortality than any conventional cardiovascular risk factor. The association is continuous and dose-dependent: every increment in fitness is associated with reduced mortality, and the greatest risk reduction occurs in moving from the lowest fitness category to the next, meaning that the least fit adults gain the most from any improvement in cardiovascular fitness.
VO2max can be measured precisely in a laboratory with maximal exercise testing, or estimated with useful accuracy from a submaximal exercise protocol such as a graded step test or treadmill test, calibrated to age and sex reference values. Knowing your VO2max percentile relative to your age and sex cohort provides an objective quantification of where you sit on the cardiovascular fitness spectrum and how much improvement would be needed to move from one fitness category to the next. At Zhen Wellness on the Isle of Man, cardiorespiratory fitness assessment is a central component of the Longevity MOT, providing one of the most important longevity biomarkers available in a practical, accessible format.
- QRISK3 misclassifies significant proportions of individuals because it omits ApoB, Lp(a), insulin resistance, and fitness
- ApoB counts atherogenic particles directly; discordance with LDL is most clinically significant in metabolic syndrome
- Lp(a) elevated in 20% of people; not measurable in standard panels; not modified by statins; test once and know
- Coronary artery calcium score directly measures atherosclerosis burden; zero score is genuinely reassuring
- VO2max is the most powerful all-cause mortality predictor; moving from lowest to second-lowest fitness category produces the greatest gain
- Every 1 MET increase in exercise capacity is associated with 12% reduction in all-cause mortality (Myers, NEJM 2002)
- Cardiorespiratory fitness assessment should be a vital sign measured in every adult health assessment over 40
Sources
- Kokkinos, P., et al. (2022). Cardiorespiratory fitness and mortality risk across the spectra of age, race, and sex. JAMA Network Open, 5(5), e2218174.
- Myers, J., et al. (2002). Exercise capacity and mortality among men referred for exercise testing. New England Journal of Medicine, 346(11), 793-801.
- Benn, M., et al. (2019). Apolipoprotein B levels, APOB alleles, and risk of ischemic cardiovascular disease. Atherosclerosis, 282, 174-183.
- Blaha, M.J., et al. (2016). Associations between coronary artery calcium and noncardiovascular disease in the Framingham Heart Study. Journal of the American College of Cardiology, 67(13), 1549-1561.
- Ridker, P.M., et al. (2005). C-reactive protein and the prevention of cardiovascular disease. New England Journal of Medicine, 352(1), 20-28.