# Intra-Individual Variability of Lipoprotein(a) After Acute Coronary Syndrome: A Long-Term Cohort Study

## TL;DR

This study finds that Lp(a) levels in heart attack patients can change significantly in the months after discharge, especially for those with intermediate risk, suggesting repeat testing could improve risk assessment.

## Contribution

The study reveals that Lp(a) variability after ACS is common and provides insights into optimal timing for repeat measurements to improve cardiovascular risk stratification.

## Key findings

- 57.9% of patients showed clinically significant Lp(a) variability after ACS.
- Incomplete revascularization was an independent predictor of high Lp(a) variability.
- Early repeat Lp(a) measurements may improve risk reclassification in intermediate-risk patients.

## Abstract

Background: Lipoprotein(a) [Lp(a)] is a causal and independent risk factor for atherosclerotic cardiovascular disease (ASCVD) and is largely genetically determined. However, recent studies indicate significant intra-individual variability, particularly among patients with intermediate Lp(a) levels (30–50 mg/dL). Yet, data on long-term variability are limited, and acute coronary syndrome (ACS) may further influence Lp(a) levels, raising questions regarding the optimal timing of assessment after ACS. Methods: We studied 235 ACS patients across two follow-up cohorts. Baseline Lp(a) was measured 24 h before hospital discharge. Cohort A had follow-up measurements at 4 months and 8 months; Cohort B had them at 5 years. Clinically meaningful intra-individual variability was defined as ≥20 mg/dL or ≥25% change. Results: 57.9% of patients exhibited clinically significant Lp(a) variability. Changes in risk category occurred in 15.3% of patients in the baseline high-risk group, 60.6% of patients in the intermediate-risk group, and 5.5% of patients in the baseline low-risk group. In the multivariable analysis, incomplete revascularization was an independent predictor of high Lp(a) variability (odds ratio (OR) 2.22; 95% confidence interval (CI) 1.14–4.31; p = 0.02) while female sex and age-adjusted menopause showed a trend (OR 1.92; 95% CI 0.93–4.00; p = 0.08 and OR 11.18; 95% CI 0.79–157.58; p = 0.07, respectively) without reaching statistical significance. The median absolute changes from baseline to 4-month and from baseline to 5-year follow-up were 7.9 mg/dL (interquartile range (IQR) 3.0–18.9) and 10.7 mg/dL (IQR 3.0–21.7), respectively. Concordance between 4- and 8-month Lp(a) measurements was excellent. Conclusions: Early post-ACS intra-individual variability in Lp(a) is common, mainly affecting risk reclassification in intermediate-risk patients. In those patients, early, targeted, repeat Lp(a) measurement may improve cardiovascular risk stratification, whereas mid- to long-term reassessment appears unnecessary.