Impact of routine measurement of Lp(a) on CV risk reclassification
Finding very high lipoprotein(a): the need for routine assessment
Introduction and methods
Lp(a) assessment is not included in routine lipid measurement in most hospitals, despite the recommendation to measure Lp(a) at least once in every person’s life in the 2019 ESC/EAS guidelines . Moreover, ASCVD risk algorithms, like SCORE  and SMART , do not incorporate Lp(a).
In this study, the impact of a single routine measurement of Lp(a) on CV risk reclassification was evaluated.
During 1 year, Lp(a) levels were routinely measured in 12,437 individuals who underwent clinical lipid profiling in a tertiary hospital setting (Amsterdam UMC, The Netherlands). Cases were defined as those with very high Lp(a) levels >99th percentile (in this study population: 387.8 nmol/L). 119 Cases were matched by age and sex to 119 individuals with low Lp(a) levels (≤20th percentile) from the same sample. 30.7% Of patients had a history of ASCVD. Lp(a) levels were measured by an isoform, independent, second-generation assay (Roche Diagnostics).
The primary outcome was ASCVD prevalence, a composite of prior fatal or non-fatal MI, revascularization therapy, ischemic stroke, and peripheral arterial disease. Prevalence of MI was a key secondary outcome.
- Median Lp(a) in the very high Lp(a) group was 460 nmol/L (IQR: 418-533) compared to 7 nmol/L (IQR 7-7) in the low Lp(a) group.
- Prevalence of ASCVD was 40.3% in the very high Lp(a) group compared with 21.0% in the low Lp(a) group (OR 2.64, 95%CI: 1.46-4.88, P=0.002).
- Prevalence of MI was also higher in patients with very high Lp(a) levels compared to patients with low Lp(a) levels (22.7% vs. 8.4%) (OR 3.39, 95%CI: 1.56-7.93, P=0.003).
- 70.3% Of patients in the very high Lp(a) group used at least one type of lipid-lowering therapy (LLT), compared with 42.0% of patients with low Lp(a) levels (P<0.001).
- 39.8% Of patients in the very high Lp(a) group treated with LLT reached their recommend LDL-c target vs. 58.0% of patients in the low Lp(a) group (P=0.041).
- Incorporation of Lp(a) into the SCORE algorithm resulted in the very high Lp(a) group to 31% upward reclassification of patients. Incorporation of Lp(a) in the SMART algorithm led to a reclassification of 62.5% of patients with very high Lp(a) levels to a higher risk category.
In this cross-sectional case-control study the risk of ASCVD was 2.6 fold higher in patients with very high Lp(a) levels compared to those with low Lp(a) levels. There is a high impact of the addition of Lp(a) to risk algorithms; reclassification for one-third of individuals with very high Lp(a) in primary prevention and more than 60% of patients with very high Lp(a) in secondary prevention.
The authors conclude: ‘These findings further support routine measurement of Lp(a) as an integral part of cholesterol measurement’.