Lipoprotein(a) cascade screening in coronary artery disease

Elevated lipoprotein(a) [Lp(a)] contributes to coronary artery disease (CAD). This study aimed to determine the effectiveness of cascade screening for elevated Lp(a) in patients with CAD.

Lp(a)-based cascade screening in first-degree relatives (FDR) and second-degree relatives (SDR) of index patients with CAD was performed. Index patients were recruited into pre-defined Lp(a) strata: low (<70 nmol/L), moderately elevated (70-169 nmol/L), and elevated (≥170 nmol/L). Proportions of elevated Lp(a) in relatives were determined within each index stratum, and participation rate was evaluated.

735 index patients (mean age 66.5 years, 76.9% male) participated, with 333, 149, and 253 in the low, moderately elevated, and elevated Lp(a) strata, respectively. Of 1120 invited relatives, 764 relatives (68.2%) were screened. Lp(a) was elevated in 30.2% of FDR and 19.4% of SDR of index patients with elevated Lp(a) compared with 6.2% in FDR (p < 0.001) and 5.6% in SDR (p = 0.007) of index patients with low Lp(a). The number (95%CI) of FDR needed to be screened to identify one individual with elevated Lp(a) was 3.3 (2.7-4.2) when the index patient had elevated Lp(a), compared with 16.1 (10.0-30.8) for low Lp(a) (p < 0.001). Corresponding numbers for SDR were 5.1 (3.4-8.8) and 17.8 (9.3-45.2) (p = 0.006).

Cascade screening for elevated Lp(a) in relatives of patients with CAD is feasible in a real-world setting. Screening was up to five times more effective when initiated from patients with elevated Lp(a) than with low.