Plasma Lipoprotein(a) measured in routine clinical care and the association with incident calcified aortic valve stenosis during a 14-year observational period

Background and aims: Lipoprotein(a) [Lp(a)] is a causal cardiovascular risk factor recommended to be measured at least once in a lifetime. We aimed to establish the association between routinely measured Lp(a) levels and the development of incident calcified aortic valve stenosis (CAVS).

Methods: This retrospective registry based observational study includes all individuals who had their Lp(a) measured in clinical routine between 2003 and 2017 at Karolinska University Laboratory, Stockholm. Data on pre-existing medical conditions, pharmacological treatment and outcomes were retrieved from national patient registries.

Results: The study comprised 23,298 individuals of which 489 received a CAVS diagnosis during the study period. The CAVS group (71 ± 11 years, 62% males) had a larger cardiovascular burden than the group without CAVS (55 ± 17 years and 48% males). Individuals with CAVS had higher Lp(a) 90th percentile (117 mg/dL or 249 nmol/L) than those without (89 mg/dL or 179 nmol/L) (p < 0.001), a difference seen in both sexes. The incident rates of CAVS per 10,000 person-years was 22.3 for individuals at >90th Lp(a) percentile compared to 12.8 for the 0^th - 50th percentiles (p < 0.001). Sex and age adjusted hazard ratios for development of incident CAVS was 1.53 (95% CI 1.08-2.15; p = 0.016) and for surgical or endovascular intervention for CAVS 1.42 (95% CI 0.73-2.79; p = 0.304) for individuals at Lp(a) > 90th percentile compared to the 0^th - 50th percentile.

Conclusions: Lp(a) measured in the clinical routine is higher in individuals with CAVS. An Lp(a) level above >90th percentile is associated with the development of incident CAVS during a 14-year observational period.