Lipoprotein (a) variability in high cardiovascular risk individuals with hypertriglyceridemia and controlled LDL-C on statin therapy in REDUCE-IT.

BACKGROUND: Although repeated testing of lipoprotein(a) [Lp(a)] is generally not recommended because of the genetically determined nature of concentrations, reports of significant intraindividual variability in serial assessments have challenged the single lifetime measurement framework. OBJECTIVE: To determine sources of Lp(a) variability among individuals with elevated triglyceride levels and well-controlled low-density lipoprotein cholesterol (LDL-C). METHODS: Using Lp(a) assessments at baseline, month 12, and month 24 from participants in the Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT), we identified characteristics that could support repeated testing. RESULTS: Among 386 participants with baseline Lp(a) 50 to <70 mg/dL, 140 (36.3%) had at least 1 subsequent assessment ≥70 mg/dL, whereas among 630 participants with baseline Lp(a) ≥70 mg/dL, 133 (21.1%) had at least 1 subsequent assessment <70 mg/dL. Baseline Lp(a), sex (female vs male), race, and several other characteristics were related to variability. CONCLUSION: Among individuals at high cardiovascular risk with hypertriglyceridemia and controlled LDL-C on statin therapy, considerable variability was observed over 24 months. These findings suggest multiple assessments may be warranted for Lp(a)-related risk stratification and, potentially, eligibility for Lp(a)-targeted treatments, particularly among individuals with relatively high concentrations or certain demographic and clinical characteristics.