Association Between Lipoprotein A Levels and Vulnerable Atherosclerotic Plaques

Elevated lipoprotein(a) [Lp(a)] is an established cardiovascular risk factor, but its association with imaging-defined vulnerable plaque features remains incompletely characterized.

We systematically searched PubMed, Scopus, and Embase for observational studies comparing elevated versus lower Lp(a) levels and reporting thin-cap fibroatheroma (TCFA) or lipid-rich plaques. Random-effects meta-analyses were performed, with the primary TCFA analysis restricted to optical coherence tomography (OCT)-based studies. Sensitivity and geography-based subgroup analyses were also conducted.

Seven studies involving 1,008 patients were included. Elevated Lp(a) was associated with greater odds of TCFA in the primary OCT-based analysis (OR 2.90, 95% CI 1.63 to 5.18; I²=51.0%) and with greater odds of lipid-rich plaques (OR 3.03, 95% CI 1.53 to 6.00; I²=76.9%). Including the MDCTA/MRI study in a TCFA sensitivity analysis yielded a similar association. No significant subgroup differences were observed between Asian and Western studies.

Elevated Lp(a) is associated with imaging-defined features of plaque vulnerability, including TCFA and lipid-rich plaques. These findings should be interpreted cautiously given heterogeneity and the limited number of studies.