Long-term prognostic value of apolipoprotein B levels in patients with very premature (≤40 years) acute coronary syndrome.

BACKGROUND

Apolipoprotein B (apoB) is a recognized risk factor for acute coronary syndrome (ACS); however, its prognostic value in secondary prevention and superiority over other lipid biomarkers, especially in younger populations, remains uncertain.

OBJECTIVE

To investigate whether elevated baseline apoB predicts recurrent cardiovascular events in patients who experienced an ACS at ≤40 years of age and compare its incremental predictive value with that of other lipid biomarkers.

METHODS

We recruited 405 consecutive patients who survived an ACS at ≤40 years of age. Clinical endpoints included major adverse cardiovascular events (MACE): cardiac death, readmission for ACS or ventricular arrhythmias, ischemic stroke, and coronary revascularization due to clinical deterioration. The association between baseline lipid biomarkers and recurrent MACE risk was assessed using multivariable Cox regression. Model performance was evaluated based on discrimination and reclassification.

RESULTS

Of 378 young ACS survivors (33.7 ± 4.3 years) with follow-up data, 139 (36.8%) experienced a MACE over a median 8-year (5.2-12.5 years) follow-up. Elevated baseline apoB was independently associated with a higher risk of recurrent MACE (hazard ratio per 10 mg/dL: 1.082, P= .007). This association remained significant even after additionally accounting for low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (non-HDL-C). Conversely, apoB adjustment attenuated the LDL-C and non-HDL-C associations. Compared with LDL-C and non-HDL-C, apoB was associated with greater risk of recurrent MACE, and upon addition to conventional cardiovascular risk factors, yielded the greatest improvement in discrimination and reclassification.

CONCLUSION

Baseline apoB may act as a driver for long-term recurrence of MACE in very young ACS survivors, highlighting its potential clinical utility to improve risk stratification beyond traditional lipid measurements.