Association of lipoprotein(a) with platelet aggregation and thrombogenicity in patients undergoing percutaneous coronary intervention

Lipoprotein(a), platelet function and cardiovascular disease

Lipoprotein(a) (Lp(a)) is associated with atherothrombosis through several mechanisms, including putative antifibrinolytic properties. However, genetic association studies have not demonstrated an association between high plasma levels of Lp(a) and the risk of venous thromboembolism, and studies in patients with highly elevated Lp(a) levels have shown that Lp(a) lowering does not modify the clotting properties of plasma ex vivo. Lp(a) can interact with several platelet receptors, providing biological plausibility for a pro-aggregatory effect. Observational clinical studies suggest that elevated plasma Lp(a) concentrations are associated with worse long-term outcomes in patients undergoing revascularization. Furthermore, in these patients, those with elevated plasma Lp(a) levels derive more benefit from prolonged dual antiplatelet therapy than those with normal Lp(a) levels. The ASPREE trial in healthy older individuals treated with aspirin showed a reduction in ischaemic events in those who had a single-nucleotide polymorphism in LPA that is associated with elevated Lp(a) levels in plasma, without an increase in bleeding events. In this Review, we re-examine the role of Lp(a) in the regulation of platelet function and suggest areas of research to define further the clinical relevance to cardiovascular disease of the observed associations between Lp(a) and platelet function.

Impact of Elevated Lipoprotein A on Clinical Outcomes in Patients Undergoing Percutaneous Coronary Intervention: A Systematic Review and Meta-analysis

Lipoprotein(a) (Lp(a)) is an inherited lipoprotein particle associated with increased risk of atherosclerotic cardiovascular (CV) diseases. However, its impact on outcomes after percutaneous coronary intervention (PCI) remains unclear. The objective of this study was to assess the relationship between elevated Lp(a) levels and major adverse cardiovascular events (MACEs) and other outcomes in patients undergoing PCI. We systematically searched Embase, MEDLINE/PubMed, and Web of Science for studies published from 2015 to 2024 comparing CV outcomes between patients with elevated versus non-elevated Lp(a) levels after PCI. Primary outcome was MACE. Secondary outcomes included all-cause mortality, CV mortality, stroke, myocardial infarction, and revascularization. Risk ratios (RRs) were pooled using a random-effect model. Fifteen studies with 45,059 patients were included. Patients with elevated Lp(a) had a significantly higher risk of MACE (RR 1.38, 95% confidence interval (CI) 1.23-1.56). Elevated Lp(a) was also associated with increased risks of all-cause death (RR 1.26), CV death (RR 1.58), myocardial infarction (RR 1.44), revascularization (RR 1.38), and stroke (RR 1.18). Heterogeneity was considerable for some outcomes. This meta-analysis demonstrates that elevated Lp(a) levels are associated with worse CV outcomes, including higher rates of MACE, mortality, and recurrent ischemic events in patients undergoing PCI. Novel therapeutic approaches specifically targeting Lp(a) reduction may help mitigate residual CV risk in this high-risk population.

Burden of elevated lipoprotein(a) among patients with atherosclerotic cardiovascular disease: Evidence from a systematic literature review and feasibility assessment of meta-analysis

BACKGROUND

Elevated lipoprotein(a) [Lp(a)] level is an independent genetic risk factor that increases the risk of atherosclerotic cardiovascular disease (ASCVD) by 2-4 fold. We aimed to report the burden of clinically relevant elevated Lp(a) in secondary prevention ASCVD population as the evaluation of such evidence is lacking.

METHODS

A systematic literature review (SLR) was conducted using Embase®, MEDLINE®, and MEDLINE® In-Process databases to identify studies reporting burden of elevated Lp(a) levels from January 1, 2010, to March 28, 2022. Full-text, English-language studies including ≥500 participants with ≥1 Lp(a) assessment were included.

RESULTS

Sixty-one studies reported clinical burden of elevated Lp(a). Of these, 25 observational studies and one clinical trial reported clinical burden of clinically relevant elevated Lp(a) levels. Major clinical outcomes included major adverse cardiovascular event (MACE; n = 20), myocardial infarction (MI; n = 11), revascularization (n = 10), stroke (n = 10), cardiovascular (CV) mortality (n = 9), and all-cause mortality (n = 10). Elevated Lp(a) levels significantly increased the risk of MACE (n = 15) and revascularization (n = 8), while they demonstrated a trend for positive association with remaining CV outcomes. Meta-analysis was not feasible for included studies due to heterogeneity in Lp(a) thresholds, outcome definitions, and patient characteristics. Three studies reported humanistic burden. Patients with elevated Lp(a) levels had higher odds of manifesting cognitive impairment (odds ratio [OR] [95% confidence interval; CI]: 1.62 [1.11-2.37]) and disability related to stroke (OR [95% CI]:1.46 [1.23-1.72)]) (n = 2). Elevated Lp(a) levels negatively correlated with health-related quality of life (R = -0.166, p = 0.014) (n = 1). A single study reported no association between elevated Lp(a) levels and economic burden.

CONCLUSIONS

This SLR demonstrated a significant association of elevated Lp(a) levels with major CV outcomes and increased humanistic burden in secondary prevention ASCVD population. These results reinforce the need to quantify and manage Lp(a) for CV risk reduction and to perform further studies to characterize the economic burden.

Aspirin and lipoprotein(a) in primary prevention

PURPOSE OF REVIEW

Lipoprotein(a) [Lp(a)] is causally associated with cardiovascular diseases, and elevated levels are highly prevalent. However, there is a lack of available therapies to address Lp(a)-mediated risk. Though aspirin has progressively fallen out of favor for primary prevention, individuals with high Lp(a) may represent a high-risk group that derives a net benefit.

RECENT FINDINGS

Aspirin has been demonstrated to have a clear benefit in secondary prevention of cardiovascular disease, but recent primary prevention trials have at best demonstrated a small benefit. However, individuals with elevated Lp(a) may be of high risk enough to benefit, particularly given interactions between Lp(a) and the fibrinolytic system / platelets, and the lack of available targeted medical therapies. In secondary analyses of the Women's Health Study (WHS) and the Aspirin in Reducing Events in the Elderly (ASPREE) trial, aspirin use was associated with a significant reduction in cardiovascular events in carriers of genetic polymorphisms associated with elevated Lp(a) levels. Further studies are needed, however, as these studies focused on narrower subsets of the overall population and genetic markers.

SUMMARY

Individuals with elevated Lp(a) may benefit from aspirin therapy in primary prevention, but further study with plasma Lp(a) levels, broader populations, and randomization of aspirin are needed.

Exploring the role of lipoprotein(a) in cardiovascular diseases and diabetes in Chinese population

A high level of lipoprotein (a) in the plasma has been associated with a variety of cardiovascular diseases and is considered to be an independent predictor of some other diseases. Based on recent studies, the concentration levels of Lp(a) in the Chinese population exhibit a distinctive variation from other populations. In the Chinese population, a high level of Lp(a) indicates a higher incidence of revascularization, platelet aggregation, and thrombogenicity following PCI. Increased risk of atherosclerotic cardiovascular disease (ASCVD) in Chinese population has been linked to higher levels of Lp(a), according to studies. More specifically, it has been found that in Chinese populations, higher levels of Lp(a) were linked to an increased risk of coronary heart disease, severe aortic valve stenosis, deep vein thrombosis in patients with spinal cord injuries, central vein thrombosis in patients receiving hemodialysis, and stroke. Furthermore, new and consistent data retrieved from several clinical trials also suggest that Lp (a) might also play an essential role in some other conditions, including metabolic syndrome, type 2 diabetes and cancers. This review explores the clinical and epidemiological relationships among Lp(a), cardiovascular diseases and diabetes in the Chinese population as well as potential Lp(a) underlying mechanisms in these diseases. However, further research is needed to better understand the role of Lp(a) in cardiovascular diseases and especially diabetes in the Chinese population.

Lipoprotein(a) and Atherosclerotic Cardiovascular Diseases: Evidence from Chinese Population

Cardiovascular disease (CVD) is the leading cause of mortality worldwide. Multiple factors are involved in CVD, and emerging data indicate that lipoprotein(a) (Lp(a)) may be associated with atherosclerotic cardiovascular disease (ASCVD) independent of other traditional risk factors. Lp(a) has been identified as a novel therapeutic target. Previous studies on the influence of Lp(a) in CVD have mainly used in western populations. In this review, the association of plasma Lp(a) concentration with ASCVD was summarized, with regards to epidemiological, population-based observational, and pathological studies in Chinese populations. Lp(a) mutations and copy number variations in Chinese populations are also explored. Finally, the impact of plasma Lp(a) levels on patients with type 2 diabetes mellitus, cancer, and familial hypercholesterolemia are discussed.

Independent association of Lp(a) with platelet reactivity in subjects without statins or antiplatelet agents

The physiological effect of Lp(a) on platelet activity is unclear. Previous studies explored the relationship between Lp(a) and platelet aggregation in patients taking statins and antiplatelet agents, but few was conducted in individuals without the bias of those drugs that either influence Lp(a) or platelet activity. The aim of this study was to assess the relationship between Lp(a) levels and platelet aggregation in subjects not taking statins or antiplatelet drugs. A hospital-based cross-sectional study was conducted to investigate the independent contribution of Lp(a) to platelet activity by controlling the effects of potential confounding factors including lipoprotein-associated phospholipase A2 [Lp-PLA2]. Blood samples were collected from 92 subjects without statins or antiplatelet agents from the Second Xiangya Hospital. The univariate correlation analysis showed a significant correlation between AA-induced average aggregation rate [AAR] and ApoB (r = 0.324, P = 0.002), ApoA1 (r = 0.252, P = 0.015), Lp(a) (r = 0.370, P < 0.001), Lp-PLA2 (r = 0.233, P = 0.025) and platelet counts [PLT] (r = 0.389, P < 0.001). Multivariate regression analysis suggested that Lp(a) contributed independently to AA-induced average aggregation rate (β = 0.023, P = 0.027) after controlling for the effects of ApoB, Lp-PLA2 and platelet counts. Lp(a) is positively associated with platelet aggregation independent of Lp-PLA2, which may partly account for the atherothrombotic effect of Lp(a).

Lipids and Lipoproteins in Health and Disease: Focus on Targeting Atherosclerosis

Despite advances in pharmacotherapy, intervention devices and techniques, residual cardiovascular risks still cause a large burden on public health. Whilst most guidelines encourage achieving target levels of specific lipids and lipoproteins to reduce these risks, increasing evidence has shown that molecular modification of these lipoproteins also has a critical impact on their atherogenicity. Modification of low-density lipoprotein (LDL) by oxidation, glycation, peroxidation, apolipoprotein C-III adhesion, and the small dense subtype largely augment its atherogenicity. Post-translational modification by oxidation, carbamylation, glycation, and imbalance of molecular components can reduce the capacity of high-density lipoprotein (HDL) for reverse cholesterol transport. Elevated levels of triglycerides (TGs), apolipoprotein C-III and lipoprotein(a), and a decreased level of apolipoprotein A-I are closely associated with atherosclerotic cardiovascular disease. Pharmacotherapies aimed at reducing TGs, lipoprotein(a), and apolipoprotein C-III, and enhancing apolipoprotein A-1 are undergoing trials, and promising preliminary results have been reported. In this review, we aim to update the evidence on modifications of major lipid and lipoprotein components, including LDL, HDL, TG, apolipoprotein, and lipoprotein(a). We also discuss examples of translating findings from basic research to potential therapeutic targets for drug development.