Cascade screening for elevated Lp(a) in relatives of children who visited the pediatric lipid clinic: yield of daily clinical practice

AIMS: Cascade screening can identify individuals with elevated lipoprotein(a) [Lp(a)], a causal risk factor for atherosclerotic cardiovascular disease (ASCVD). The aim of this study is to explore the effectiveness of cascade screening with asymptomatic children as index cases to identify family members with elevated Lp(a). METHODS: In this retrospective study we used our database consisting of all children referred for a tentative diagnosis of hereditary dyslipidemia to the Amsterdam University Medical Centers pediatric lipid clinic (1989-2023). Elevated Lp(a) was defined as ≥30 mg/dL or ≥75 nmol/L. We evaluated two cascade screening approaches (opportunistic and systematic), calculated the number needed to screen (NNS) and repeated the analysis exclusively in children with FH as subgroup with particularly high cardiovascular risk. RESULTS: A total of 1,931 children were included (732 indexes, mean age (SD) 11.7 (4.5) years; 1,199 relatives, mean age (SD) 10.1 (4.4) years). In total, 480 (25%) of all children had elevated Lp(a) concentrations (≥30 mg/dL or ≥75 nmol/L). Both opportunistic (732 indexes) and systematic (316 indexes) cascade screening identified relatives with elevated Lp(a). The NNS was of 3.7 (95% CI 3.3-4.3) for the systematic approach and 4.1 (95% CI 3.8-4.6) for the opportunistic approach. In the FH subgroup, NNS were 3.9 (95% CI 3.4-4.5) and 4.3 (95% CI 3.9-4.8), respectively. CONCLUSION: Our findings suggest that cascade screening using children as index cases is an effective strategy to identify asymptomatic relatives at risk. Cardiovascular risk assessment should include Lp(a), especially in patients with FH who face an even higher cardiovascular risk. Until effective therapies become available, management should focus on modifiable risk factors.