No Relationship Between Lipoprotein (a) Levels and Mortality in Symptomatic PAD

In patients with PAD, elevated lipoprotein (a) levels following endovascular repair are not associated with increased risk for mortality.

Elevated lipoprotein (a) (Lp(a)) levels are not associated with mortality outcomes among patients with symptomatic peripheral artery disease (PAD), according to results of a study published in Atherosclerosis.

Data for this analysis were sourced from the Vienna LIP-LEAD (Lipids in Lower Extremity Artery Disease) study which was a retrospective review of patient data collected between 2013 and 2018 at the Medical University of Vienna in Austria. Risk of mortality was evaluated among patients with symptomatic PAD on the basis of Lp(a) levels measured in nmol/L (n=964) or mg/dl (n=258).

For the nmol/L analysis, when patients were stratified by Lp(a) tertile, significant group differences were observed for sex, BMI, systolic blood pressure, low- and high-density lipoprotein cholesterol levels, total cholesterol levels, and use of angiotensin converting enzyme inhibitors and ezetimibe (all P £.044).

During a median follow-up of 4.3 (IQR, 3.0-5.6) years, 326 fatal events occurred, corresponding to a 33.8% mortality rate. The cardiovascular (CV)-specific mortality rate was 14.6%, or 3.4% annually. Stratified by Lp(a) tertile, no significant risk for all-cause (P =.654) or CV (P =.244) mortality was observed. Similarly, no group differences were observed in the univariate, multivariate, or Cox-regression analyses even when stratifying for traditional conventional risk factors. No evidence of a relationship between Lp(a) levels and stenosis localization was observed (P =.881).

…this study does not demonstrate an association with CV-death or a specific pattern of lesion site with Lp(a) in patients with symptomatic PAD.

For the mg/dl analysis, the tertiles of Lp(a) were more well-balanced with no significant group differences observed at baseline beyond Lp(a) levels.

During a median follow-up of 7.6 (IQR, 3.2-8.1) years, there were a total of 123 fatal events, corresponding with a 47.7% mortality rate. For CV mortality, the rate was 24.8% overall or 3.3% every year. Consistent with the previous cohort, Lp(a) levels did not associate with all-cause (P =.883) or CV (P =.321) mortality.

The results of this study may have been biased, as Lp(a) was evaluated during the acute phase of disease prior to endovascular repair.

“…this study does not demonstrate an association with CV-death or a specific pattern of lesion site with Lp(a) in patients with symptomatic PAD,” the study authors wrote. “However, while this is in contrast to most studies on the secondary prevention of CAD and a large proportion of patients with PAD remains asymptomatic, further analyses, especially in the latter cohort and extended long-term follow-up studies are warranted.”

References:

Zierfuss B, Höbaus C, Feldscher A, et al. Lipoprotein (a) and long-term outcome in patients with peripheral artery disease undergoing revascularization. Atherosclerosis. Published online October 12, 2022. doi:10.1016/j.atherosclerosis.2022.10.002