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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.

Aims Calcific aortic valve stenosis (CAVS) is characterized by a fibrocalcific process. Studies have shown an association between CAVS and the activation of platelets. It is believed that shear stress associated with CAVS promotes the activation of platelets. However, whether platelets actively participate to the mineralization of the aortic valve (AV) and the progression of CAVS is presently unknown. To identify the role of platelets into the pathobiology of CAVS. Methods and results Explanted control non-mineralized and mineralized AVs were examined by scanning electron microscope (SEM) for the presence of activated platelets. In-depth functional assays were carried out with isolated human valve interstitial cells (VICs) and platelets as well as in LDLR−/− apoB100/100 IGFII (IGFII) mice. Scanning electron microscope and immunogold markings for glycoprotein IIb/IIIa (GPIIb/IIIa) revealed the presence of platelet aggregates with fibrin in endothelium-denuded areas of CAVS. In isolated VICs, collagen-activated platelets induced an osteogenic programme. Platelet-derived adenosine diphosphate induced the release of autotaxin (ATX) by VICs. The binding of ATX to GPIIb/IIIa of platelets generated lysophosphatidic acid (LysoPA) with pro-osteogenic properties. In IGFII mice with CAVS, platelet aggregates were found at the surface of AVs. Administration of activated platelets to IGFII mice accelerated the development of CAVS by 2.1-fold, whereas a treatment with Ki16425, an antagonist of LysoPA receptors, prevented platelet-induced mineralization of the AV and the progression of CAVS. Conclusions These findings suggest a novel role for platelets in the progression of CAVS.

Background Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition reduces plasma concentrations of most atherogenic lipoproteins such as low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (apoB) and lipoprotein(a) [Lp(a)]. Atherogenic lipoprotein concentrations have also been linked with calcific aortic valve stenosis (CAVS). Purpose 1) To determine the association between genetic variants in PCSK9 and lipoprotein-lipid levels, 2) to determine whether loss of function (LOF) in PCSK9 is associated with CAVS and 3) to evaluate if PCSK9 could be implicated in aortic valve interstitial cells (VICs) calcification. Methods We built a weighted genetic risk score (wGRS) using 10 single nucleotide polymorphisms at the PCSK9 locus associated with LDL-C in the Global Lipids Genetics Consortium. We determined the association between the wGRS and LDL-C, apoB and Lp(a)] in 9692 participants of the EPIC-Norfolk study using linear regression. We investigated the association between the LOF PCSK9 R46L variant and CAVS risk in a meta-analysis of published (three Copenhagen studies, 1463 cases and 101,620 controls) and unpublished studies (UK Biobank, 1350 cases and 349,043 controls, Malmö Diet and Cancer study, 682 cases and 5963 controls and EPIC-Norfolk, 508 cases and 20,421 controls) prospective, population-based studies using logistic regression adjusted for age and sex. We evaluated PCSK9 expression and localization in explanted aortic valves by capillary Western blot and immunohistochemistry in patients with and without CAVS. Von Kossa staining was used to visualize aortic leaflet calcium deposits. We also assessed VICs calcification potential under oxidative stress condition. Results In EPIC-Norfolk, the wGRS was significantly associated with TC, LDL-C, and apoB (all p Conclusion PCSK9LOF variants are associated with lifelong reductions in non-Lp(a) apoB-containing lipoprotein levels and a lower risk of coronary artery disease and CAVS. PCSK9 is abundant in fibrotic and calcified aortic leaflets. Oxidative stress increases PCSK9 expression in VICs. These results support randomized clinical trials of PCSK9 inhibition in the prevention of CAVS.

This editorial refers to ‘Randomized trial of an inhibitor of secretory phospholipase A2 on atherogenic lipoprotein subclasses in statin-treated patients with coronary heart disease’, by R.S. Rosenson et al., doi:10.1093/eurheartj/ehq374 Atherosclerosis is a complex disease and in its pathogenesis depends on the interaction between lipoproteins and inflammatory mediators.1 This interaction orchestrates the progression of atherosclerosis from its earliest stage when oxidized lipoproteins and leucocytes penetrate dysfunctional endothelium and enter the subendothelial space, right until the end of the process when the plaque becomes unstable and ruptures, leading to a clinical event. Whereas our pharmacological armatorium that targets the lipid component of the risk factor spectrum has been tremendously succesful with the clinical introduction of statins in the middle of the 1990s, drugs that target the inflammatory face of atherosclerosis have thus far been scarce. Among the wide range of chemokines, adhesion molecules, and pro-oxidative substances that affect macrophage recruitment into the arterial wall, members of the phospholipase A2 (PLA2) family have received considerable attention since their purification from human plasma lipoproteins in 1987.2 PLA2s are small and relatively stable ubiquitous enzymes that hydrolyse the sn -2-acyl bond of phospholipids in cell membranes as well as in lipoproteins. This enzymatic activity yields non-esterified fatty acids and lysophospholipids, which are precursors of various proinflammatory mediators including leukotrienes, eicosanoids, prostaglandins, and platelet-activating factors ( Figure 1A ).3 In addition, both circulating and lipoprotein-bound PLA2s play a role in lipoprotein remodelling by high-affinity binding to specific domains on LDLs and apolipoprotein B. Such modified or oxidized LDL particles bind with higher affinity to endothelial proteoglycans, facilitating the penetration of these atherogenic particles into the subendothelial matrix where they accumulate and trigger additional proinflammatory cascades. The recent large-scale meta-analysis of genome-wide association studies for plasma lipids …

Aims The aim of this study was to determine the contribution of physical activity and abdominal obesity to the variation in inflammatory biomarkers and incident coronary heart disease (CHD) in a European population. Methods and results In a prospective case–control study nested in the European Prospective Investigation into Cancer and Nutrition-Norfolk cohort, we examined the associations between circulating levels or activity of C-reactive protein, myeloperoxidase (MPO), secretory phospholipase A2 (sPLA2), lipoprotein-associated phospholipase A2 (Lp-PLA2), fibrinogen, adiponectin, waist circumference, physical activity, and CHD risk over a 10-year period among healthy men and women (45–79 years of age). A total of 1002 cases who developed fatal or non-fatal CHD were matched to 1859 controls on the basis of age, sex, and enrolment period. Circulating levels of C-reactive protein, sPLA2 (women only), fibrinogen, and adiponectin were linearly associated with increasing waist circumference and decreasing physical activity levels. After adjusting for waist circumference, physical activity, smoking, diabetes, systolic blood pressure, low-density lipoprotein and high-density lipoprotein cholesterol levels, and further adjusted for hormone replacement therapy in women, C-reactive protein, MPO (men only), sPLA2, fibrinogen, but not Lp-PLA2 and adiponectin were associated with an increased CHD risk. Conclusion Inactive participants with an elevated waist circumference were characterized by deteriorated levels of inflammatory markers. However, several inflammatory markers were associated with an increased CHD risk, independent of underlying CHD risk factors such as waist circumference and physical activity levels.

AIMS: To evaluate the association of low-density lipoprotein cholesterol (LDL-C) levels in small and large LDL particles with risk of incident coronary heart disease (CHD). METHODS AND RESULTS: We performed a prospective case-control study nested in the EPIC-Norfolk cohort. Cases were apparently healthy men and women aged 45-79 years who developed fatal or non-fatal CHD (n = 1035), and who were matched by age, gender, and enrollment time to 1920 controls who remained free of CHD. Electrophoretic characteristics of LDL particles were measured using 2-16% polyacrylamide gradient gel electrophoresis. Concentrations of LDL-C(