Levels of Lipoprotein (a) in patients with coronary artery disease with and without inflammatory rheumatic disease: a cross-sectional study

Lipoprotein(a), high-sensitivity C-reactive protein, and cardiovascular risk in patients undergoing percutaneous coronary intervention

BACKGROUND AND AIMS

In patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI), the effects of high-sensitivity C-reactive protein (hsCRP) on Lipoprotein(a) (Lp(a))-associated cardiovascular risk remains unclear. This study aimed to investigate the independent and combined association of Lp(a) and hsCRP with cardiovascular events in this specific population.

METHODS

A total of 10,424 patients with measurements of both Lp(a) and hsCRP were included in this prospective cohort study. Cox proportional hazards models and Kaplan-Meier analysis were performed to evaluate the relationship between Lp(a), hsCRP and adverse cardiac and cerebrovascular events (MACCE; all-cause death, myocardial infarction, ischemic stroke and revascularization).

RESULTS

During 5 years of follow-up, 2140 (20.5%) MACCE occurred. Elevated Lp(a) and hsCRP levels were associated with increased risks of MACCE (p<0.05). Notably, there might be a significant interaction between Lp(a) and hsCRP (P for interaction = 0.019). In the setting of hsCRP≥2 mg/L, significant higher risk of MACCE was observed with Lp(a) 15-29.9 mg/dL (HR: 1.18; 95% CI 1.01-1.39) and Lp(a) ≥30 mg/dL (HR: 1.20; 95% CI 1.04-1.39), whereas such association was attenuated when hsCRP was <2 mg/L with Lp(a) 15-29.9 mg/dL (HR: 0.94; 95% CI 0.80-1.10) and Lp(a) ≥30 mg/dL (HR: 1.12; 95% CI 0.98-1.28). Moreover, when Lp(a) and hsCRP were combined for risk stratification, patients with dual elevation of these two biomarkers had a significant higher risk of MACCE compared with the reference group (Lp(a) < 15 mg/dL and hsCRp<2 mg/L) (p<0.05).

CONCLUSIONS

In patients with CAD undergoing PCI, high Lp(a) level was associated with worse outcomes, and this association might be stronger in those with elevated hsCRP concomitantly. Evaluation of Lp(a) and hsCRP together may help identify high-risk individuals for targeted intervention in clinical utility.

Lipoprotein(a) in atherosclerotic cardiovascular disease and aortic stenosis: a European Atherosclerosis Society consensus statement

This 2022 European Atherosclerosis Society lipoprotein(a) [Lp(a)] consensus statement updates evidence for the role of Lp(a) in atherosclerotic cardiovascular disease (ASCVD) and aortic valve stenosis, provides clinical guidance for testing and treating elevated Lp(a) levels, and considers its inclusion in global risk estimation. Epidemiologic and genetic studies involving hundreds of thousands of individuals strongly support a causal and continuous association between Lp(a) concentration and cardiovascular outcomes in different ethnicities; elevated Lp(a) is a risk factor even at very low levels of low-density lipoprotein cholesterol. High Lp(a) is associated with both microcalcification and macrocalcification of the aortic valve. Current findings do not support Lp(a) as a risk factor for venous thrombotic events and impaired fibrinolysis. Very low Lp(a) levels may associate with increased risk of diabetes mellitus meriting further study. Lp(a) has pro-inflammatory and pro-atherosclerotic properties, which may partly relate to the oxidized phospholipids carried by Lp(a). This panel recommends testing Lp(a) concentration at least once in adults; cascade testing has potential value in familial hypercholesterolaemia, or with family or personal history of (very) high Lp(a) or premature ASCVD. Without specific Lp(a)-lowering therapies, early intensive risk factor management is recommended, targeted according to global cardiovascular risk and Lp(a) level. Lipoprotein apheresis is an option for very high Lp(a) with progressive cardiovascular disease despite optimal management of risk factors. In conclusion, this statement reinforces evidence for Lp(a) as a causal risk factor for cardiovascular outcomes. Trials of specific Lp(a)-lowering treatments are critical to confirm clinical benefit for cardiovascular disease and aortic valve stenosis.

Apolipoprotein (a)/Lipoprotein(a)-Induced Oxidative-Inflammatory α7-nAChR/p38 MAPK/IL-6/RhoA-GTP Signaling Axis and M1 Macrophage Polarization Modulate Inflammation-Associated Development of Coronary Artery Spasm

Objective. Apolipoprotein (a)/lipoprotein(a) (Lp(a)), a major carrier of oxidized phospholipids, and α7-nicotinic acetylcholine receptor (α7-nAChR) may play an important role in the development of coronary artery spasm (CAS). In CAS, the association between Lp(a) and the α7-nAChR-modulated inflammatory macrophage polarization and activation and smooth muscle cell dysfunction remains unknown. Methods. We investigated the relevance of Lp(a)/α7-nAChR signaling in patient monocyte-derived macrophages and human coronary artery smooth muscle cells (HCASMCs) using expression profile correlation analyses, fluorescence-assisted cell sorting flow cytometry, immunoblotting, quantitative real-time polymerase chain reaction, and clinicopathological analyses. Results. There are increased serum Lp(a) levels (3.98-fold, $p=0.011$ ) and macrophage population (3.30-fold, $p=0.013$ ) in patients with CAS compared with patients without CAS. Serum Lp(a) level was positively correlated with high-sensitivity C-reactive protein ( $r^2=0.48$ , $p<0.01$ ), IL-6 ( $r^2=0.38$ , $p=0.03$ ), and α7-nAChR ( $r^2=0.45$ , $p<0.01$ ) in patients with CAS, but not in patients without CAS. Compared with untreated or low-density lipoprotein- (LDL-) treated macrophages, Lp(a)-treated macrophages exhibited markedly enhanced α7-nAChR mRNA expression ( $p<0.01$ ) and activity ( $p<0.01$ ), in vitro and ex vivo. Lp(a) but not LDL preferentially induced CD80+ macrophage (M1) polarization and reduced the inducible nitric oxide synthase expression and the subsequent NO production. While shRNA-mediated loss of α7-nAChR function reduced the Lp(a)-induced CD80+ macrophage pool, both shRNA and anti-IL-6 receptor tocilizumab suppressed Lp(a)-upregulated α7-nAChR, p-p38 MAPK, IL-6, and RhoA-GTP protein expression levels in cultures of patient monocyte-derived macrophages and HCASMCs. Conclusions. Elevated Lp(a) levels upregulate α7-nAChR/IL-6/p38 MAPK signaling in macrophages of CAS patients and HCASMC, suggesting that Lp(a)-triggered inflammation mediates CAS through α7-nAChR/p38 MAPK/IL-6/RhoA-GTP signaling induction, macrophage M1 polarization, and HCASMC activation.