Does repeat measurement of lipoprotein(a) molar concentration improve risk prediction for incident coronary artery disease compared to a single measurement?
A single accurate measurement of lipoprotein(a) molar concentration is sufficient to inform coronary artery disease risk, as repeat measurements are highly correlated and do not provide independent predictive value.
BACKGROUND When indicated, guidelines recommend measurement of lipoprotein(a) for cardiovascular risk assessment. However, temporal variability in lipoprotein(a) is not well understood, and it is unclear if repeat testing may help refine risk prediction of coronary artery disease (CAD). OBJECTIVES The authors examined the stability of repeat lipoprotein(a) measurements and the association between instability in lipoprotein(a) molar concentration with incident CAD. METHODS The authors assessed the correlation between baseline and first follow-up measurements of lipoprotein(a) in the UK Biobank (n = 16,017 unrelated individuals). The association between change in lipoprotein(a) molar concentration and incident CAD was assessed among 15,432 participants using Cox proportional hazards models. RESULTS Baseline and follow-up lipoprotein(a) molar concentration were significantly correlated over a median of 4.42 years (IQR: 3.69-4.93 years; Spearman rho = 0.96; P 5 years (rho = 0.96). Although there were negligible-to-modest associations between statin use and changes in lipoprotein(a) molar concentration, statin usage was associated with a significant increase in lipoprotein(a) among individuals with baseline levels ≥70 nmol/L. Follow-up lipoprotein(a) molar concentration was significantly associated with risk of incident CAD (HR per 120 nmol/L: 1.32 95% CI: 1.16-1.50; P = 0.0002). However, the delta between follow-up and baseline lipoprotein(a) molar concentration was not significantly associated with incident CAD independent of follow-up lipoprotein(a) (P = 0.98). CONCLUSIONS These findings suggest that, in the absence of therapies substantially altering lipoprotein(a), a single accurate measurement of lipoprotein(a) molar concentration is an efficient method to inform CAD risk.
“The baseline and follow-up Lp(a) molar concentration measures are highly correlated with 85% of the repeat values being within 25 nmol/L of each other. When predicting events, the follow-up Lp(a) concentration did not yield additional information beyond the baseline Lp(a).”
Trinder et al. (Tue,) studied this question.