Cardiovascular Risk Assessment with Apolipoprotein B

Limitations of LDL Cholesterol Measurement

The American College of Cardiology acknowledges that LDL cholesterol has significant limitations as a clinical entity, including labor-intensive or incompletely validated direct measurement methods 1
LDL cholesterol is often indirectly calculated from other lipid fractions and requires a relatively long fasting period, as noted by the American Heart Association 1
LDL cholesterol measurement becomes inaccurate when LDL levels are very low or triglycerides are high, according to the American College of Cardiology 1
LDL cholesterol incompletely captures the total burden of atherogenic particles in circulation, as stated by the European Society of Cardiology 1

Apo B provides a direct measure of the number of atherogenic particles present in circulation, with one Apo B molecule present on each potentially atherogenic lipoprotein particle, as recommended by the American College of Cardiology 1, 3
Atherosclerosis is more closely related to the total number of Apo B-containing particles rather than LDL cholesterol concentration, according to the European Society of Cardiology 1
Apo B has analytical and biological stability and remains valid in non-fasting samples, which is more convenient for patients, as noted by the American Heart Association 1, 4

Multiple studies have shown that Apo B is superior to LDL cholesterol in predicting cardiovascular disease events, as reported by the American College of Cardiology 1
In the Treating to New Targets (TNT) and Incremental Decrease in End Points through Aggressive Lipid Lowering (IDEAL) trials, on-treatment Apo B was a better predictor of reduced cardiovascular events than LDL cholesterol, according to the European Society of Cardiology 1
Meta-analyses consistently show Apo B as being superior to LDL cholesterol in predicting coronary heart disease events, as stated by the American Heart Association 1

Non-HDL cholesterol (total cholesterol minus HDL cholesterol) is another alternative to LDL cholesterol that quantifies cholesterol content of all atherogenic Apo B-containing lipoproteins, as recommended by the American College of Cardiology 1
Non-HDL cholesterol is highly correlated with Apo B levels and also outperforms LDL cholesterol in cardiovascular risk prediction, according to the European Society of Cardiology 1, 5
While some studies show Apo B and non-HDL cholesterol having equivalent predictive value, many epidemiological studies have identified Apo B to be either superior or equivalent to non-HDL cholesterol, as reported by the American Heart Association 3

Apo B can be measured using good immunochemical methods available on conventional autoanalyzers with good analytical performance, as noted by the European Society of Cardiology 7, 4
Unlike LDL cholesterol, Apo B measurement does not require fasting conditions and is not sensitive to moderately high triglyceride levels, according to the American College of Cardiology 7, 4
Several guidelines now recommend including Apo B measurements as adjuncts or alternatives to LDL cholesterol for risk assessment and monitoring treatment, as stated by the American Heart Association 1

Despite its advantages, Apo B has not been evaluated as a primary treatment target in statin trials, though several post-hoc analyses suggest it may be a better treatment target than LDL cholesterol, as reported by the European Society of Cardiology 7, 2
Apo B measurement carries extra expense compared to standard lipid panels, which may limit its widespread adoption, according to the American College of Cardiology 4