Apolipoprotein B: Bridging the Gap Between Evidence and Clinical Practice

There is broad agreement that ApoB is a better measure of cardiovascular risk than LDL cholesterol — and broad failure to actually use it. This Circulation review is built to close that gap.

The case for ApoB is mechanical: where LDL-C measures the cholesterol inside LDL particles, ApoB counts the atherogenic particles themselves — every LDL, VLDL, and Lp(a) particle carries exactly one. When the two disagree, as they often do in people with high triglycerides, diabetes, or obesity, it is the particle count that predicts events. The authors marshal the meta-analyses and trials showing ApoB outperforming LDL-C, then do something practical: they propose collapsing the confusing conversion tables into a single rule — use the same target number for ApoB as for LDL-C (both under 70 mg/dL for high-risk patients, for instance).

The practical takeaway is concrete: order ApoB in higher-risk patients, and when it’s elevated despite an at-goal LDL-C, treat the higher number. The resistance is inertia — LDL-C is entrenched in order sets, habits, and guidelines.

We rate the evidence high — an authoritative synthesis from a lipid-expert group in a top journal, integrating guideline data and more than 20 trials. The honest limits, which the authors note, are that it is a narrative review, the simplified 1:1 targets still need prospective validation, and several authors disclose pharmaceutical consulting. A clear, actionable case for a better number that medicine has been slow to adopt.