Background Lp(a) (lipoprotein(a)) is an independent risk factor for calcific aortic valve stenosis (CAVS). Whether patients with CAVS and high Lp(a) levels are at higher risk of valvular or cardiovascular events is unknown. The aim of this study is to determine whether higher Lp(a) levels are associated with valvular and cardiovascular outcomes in patients with CAVS. Methods and Results We identified 1962 patients from the UK Biobank with an electronic health record or self‐reported CAVS diagnosis but who did not previously undergo aortic valve replacement (AVR) and had a minimal follow‐up time of 2.5 years. Cox proportional hazard regression was used to evaluate the effect of Lp(a) on AVR, AVR or cardiac death, and valvular or cardiovascular events (AVR, cardiac death, myocardial infarction, stroke, heart failure, or coronary artery bypass grafting). The maximal follow‐up time was set to 5 years. During the follow‐up, 198 patients underwent AVR, 260 had AVR or cardiac death, and 435 had at least 1 valvular or cardiovascular event. Patients with Lp(a) levels ≥125 versus <125 nmol/L were at higher risk of AVR (hazard ratio [HR], 1.58 [95% CI, 1.17–2.12]), AVR or cardiac death (HR, 1.43 [95% CI, 1.10–1.86]), and cardiovascular or valvular events (HR, 1.36 [95% CI, 1.11–1.68]). Point estimates were comparable in men versus women, younger versus older patients, and in patients with higher versus lower plasma C‐reactive protein levels. Conclusions In patients with CAVS, Lp(a) levels predicted a higher risk of valvular and cardiovascular outcomes. The impact of Lp(a)‐lowering therapies on valvular and cardiovascular health should be assessed in a long‐term randomized clinical trial.
Aims RNA interference therapies targeting liver expression of the gene proprotein convertase subtilisin/kexin type 9 (PCSK9) lower LDL-cholesterol (LDL-C) and apolipoprotein B (apoB) levels. As opposed to monoclonal antibodies, which neutralise PCSK9 circulating protein, their effect on atherosclerotic cardiovascular disease (ASCVD) outcomes is unknown. We used genetic variants in the PCSK9 locus influencing PCSK9 function or gene expression in the liver to determine whether antibodies against PCSK9 and RNA interference therapies could have comparable effects on ASCVD.Methods and results We performed genome-wide genotyping and RNA sequencing of 504 human liver sample and identified a genetic variant (rs472495) explaining 5.6% of liver PCSK9 gene expression to mimic lifelong RNA interference of PCSK9. We used the PCSK9 R46L variant, known to alter PCSK9 function, to model antibody-based PCSK9 inhibition. For each standard deviation decrease in apoB levels, both variants were similarly associated with coronary artery disease risk: (odds ratio [OR] = 0.40, 95% confidence interval [CI]: 0.31-0.51, P = 3.7e-13 for rs472495 which affects liver PCSK9 expression) and (OR = 0.48, 95% CI: 0.43-0.55, P = 1.3e-28 for R46L which affects protein levels). Comparable effects of these two genetic inhibition approaches were observed for aortic stenosis, heart failure, ischemic stroke, Type 2 diabetes and glycemic traits as well as non-alcoholic fatty liver disease and liver enzymes.Conclusion For a given reduction in apoB levels, genetically predicted reductions in PCSK9 function (mimicking PCSK9 neutralizing antibodies) and liver PCSK9 gene expression levels (mimicking PCSK9 RNA interference) were comparably associated with a lower risk of coronary artery disease. These genetic data suggest that LDL-C/apoB reductions may provide cardiovascular benefits, regardless of how PCSK9 function is inhibited.
ABSTRACT Background Anticoagulants are routinely used by millions of patients worldwide to prevent blood clots. Yet, problems with anticoagulant therapy remain, including a persistent and cumulative bleeding risk in patients undergoing prolonged anticoagulation. New safer anticoagulant targets are needed. Methods We performed two-sample Mendelian randomization (MR) and genetic colocalization to prioritize anticoagulant targets with the strongest efficacy (venous thromboembolism [VTE] prevention) and safety (low bleeding risk) profiles. We leveraged three large-scale plasma protein datasets (deCODE, n=35,559; Fenland n = 10,708; ARIC n= 7,213) and one liver gene expression dataset (n =246) to evaluate evidence for a causal effect of 26 coagulation cascade plasma proteins on VTE from a new genome-wide association meta-analysis of 44,232 VTE cases and 847,152 controls (from the UK Biobank, FinnGen and Estonian Biobank), stroke subtypes (from UK Biobank and International Stroke Genetics consortium 73,652 cases and 1,234,808 controls), bleeding outcomes (FinnGen, n=309,154) and over one million parental lifespans (UK Biobank and LifeGen consortium). Results Genetically predicted reductions in F2 blood levels were associated with lower VTE risk (OR [odds ratio] per 1 standard deviation [SD] lower F2=0.44, 95% CI=0.38-0.51, p=2.6E-28) and cardioembolic stroke risk (OR = 0.55, 95% CI=0.39-0.76, p=4.2e-04) but not with bleeding (OR = 1.13, 95% CI=0.93-1.36, p=2.2e-01). Genetically predicted F11 reduction were associated with lower risk of VTE (OR = 0.61, 95% CI=0.58-0.64, p=4.1e-85) and cardioembolic stroke (OR = 0.77, 95% CI=0.69-0.86, p=4.1e-06), but not with bleeding (OR = 1.01, 95% CI=0.95-1.08, p=7.5e-01) (Figure 3). These MR associations were concordant across the three blood protein datasets and the hepatic gene expression dataset as well as three different MR and colocalization analyses. Conclusion These results provide strong genetic evidence that F2 and F11 may represent safe and efficacious therapeutic targets to prevent VTE and cardioembolic strokes without substantially increasing bleeding risk.
Importance:There are currently no pharmacological treatments available to slow hemodynamic progression of aortic stenosis. Plasma lipoprotein(a) concentrations predict incident aortic stenosis but its association with hemodynamic progression is controversial. Objective:To determine the association between plasma lipoprotein(a) concentrations and hemodynamic progression in patients with aortic stenosis. Design, Settings and Participants:The study included patients with aortic stenosis from 5 longitudinal clinical studies conducted from March 2001 to March 2023 in Canada and the UK. Of 757 total patients, data on plasma lipoprotein(a) concentrations and rates of hemodynamic progression assessed by echocardiography were available for 710, who were included in this analysis. Data were analyzed from March 2023 to April 2024. Exposure:Cohort-specific plasma lipoprotein(a) concentration tertiles. Main Outcomes and Measures:Hemodynamic aortic stenosis progression on echocardiography as assessed by annualized change in peak aortic jet velocity, mean transvalvular gradient, and aortic valve area. Results:Among the included patients, 497 (70%) were male and 213 (30%) were female. The mean (SD) age was 65.2 (13.1) years. Patients in the top lipoprotein(a) tertile demonstrated 41% (estimate, 1.41; 95% CI, 1.13-1.75) faster progression of peak aortic jet velocity and 57% (estimate, 1.57; 95% CI, 1.18-2.10) faster progression of mean transvalvular gradient than patients in the bottom tertile. There was no evidence of heterogeneity across the individual cohorts. Progression of aortic valve area was comparable between groups (estimate, 1.23; 95% CI, 0.71-2.12). Similar results were observed when plasma lipoprotein(a) concentrations were treated as a continuous variable. Conclusions and Relevance:In this study, higher plasma lipoprotein(a) concentrations were associated with faster rates of hemodynamic progression in patients with aortic stenosis. Lowering plasma lipoprotein(a) concentrations warrants further investigation in the prevention and treatment of aortic stenosis.
Background and aims Estimating the genetic risk of coronary artery disease (CAD) is now possible by aggregating data from genome-wide association studies (GWAS) into polygenic risk scores (PRS). Combining multiple PRS for specific circulating blood lipids could improve risk prediction. Here, we sought to evaluate the performance of PRS derived from CAD and blood lipids GWAS to predict the incidence of CAD. Methods This study included individuals aged between 40 and 69 from UK Biobank. We conducted GWAS for blood lipids measured by nuclear magnetic resonance in individuals without lipid-lowering treatments (n=73,915). Summary statistics were used to derive PRS in the remaining participants (n=318,051). A PRSCAD was derived using the CARDIoGRAMplusC4D GWAS. Hazard ratios (HR) for CAD (n=9,017 out of 301,576; median follow-up: 12.6 years) were calculated per standard deviation increase in each PRS. Models’ discrimination capacity and goodness of fit were evaluated. Results Out of 30 PRS, 27 were significantly associated with the incidence of CAD (p <0.0017). The optimal combination of PRS included PRS for CAD, VLDL-C, total cholesterol and triglycerides. Discriminative capacities were significantly increased in the model including PRSCAD and clinical risk factors (CRF) (C-statistic=0.778 [0.773-0.782]) compared to the model with CRF only (C-statistic=0.755 [0.751-0.760], difference=0.022 [0.020-0.025]). Although the C-statistic remained similar when independent lipids PRS were added to the model with PRSCAD and CRF (C-statistic=0.778 [0.773-0.783]), the goodness-of-fit was significantly increased (chi-square test statistic=20.18, p=1.56e-04). Conclusions Although independently associated with CAD incidence, blood lipids PRS provide modest improvement in the predictive performance when added to PRSCAD.
Importance There are currently no pharmacological treatments available to slow hemodynamic progression of aortic stenosis. Plasma lipoprotein(a) concentrations predict incident aortic stenosis but its association with hemodynamic progression is controversial. Objective To determine the association between plasma lipoprotein(a) concentrations and hemodynamic progression in patients with aortic stenosis. Design, Settings and Participants The study included patients with aortic stenosis from 5 longitudinal clinical studies conducted from March 2001 to March 2023 in Canada and the UK. Of 757 total patients, data on plasma lipoprotein(a) concentrations and rates of hemodynamic progression assessed by echocardiography were available for 710, who were included in this analysis. Data were analyzed from March 2023 to April 2024. Exposure Cohort-specific plasma lipoprotein(a) concentration tertiles. Main Outcomes and Measures Hemodynamic aortic stenosis progression on echocardiography as assessed by annualized change in peak aortic jet velocity, mean transvalvular gradient, and aortic valve area. Results Among the included patients, 497 (70%) were male and 213 (30%) were female. The mean (SD) age was 65.2 (13.1) years. Patients in the top lipoprotein(a) tertile demonstrated 41% (estimate, 1.41; 95% CI, 1.13-1.75) faster progression of peak aortic jet velocity and 57% (estimate, 1.57; 95% CI, 1.18-2.10) faster progression of mean transvalvular gradient than patients in the bottom tertile. There was no evidence of heterogeneity across the individual cohorts. Progression of aortic valve area was comparable between groups (estimate, 1.23; 95% CI, 0.71-2.12). Similar results were observed when plasma lipoprotein(a) concentrations were treated as a continuous variable. Conclusions and Relevance In this study, higher plasma lipoprotein(a) concentrations were associated with faster rates of hemodynamic progression in patients with aortic stenosis. Lowering plasma lipoprotein(a) concentrations warrants further investigation in the prevention and treatment of aortic stenosis.
Background and Aims RNA-based, antibody-based, and genome editing-based therapies are currently under investigation to determine if the inhibition of angiopoietin-like protein-3 (ANGPTL3) could reduce lipoprotein-lipid levels and atherosclerotic cardiovascular disease (ASCVD) risk. Mendelian randomisation (MR) was used to determine whether genetic variations influencing ANGPTL3 liver gene expression, blood levels, and protein structure could causally influence triglyceride and apolipoprotein B (apoB) levels as well as coronary artery disease (CAD), ischaemic stroke (IS), and other cardiometabolic diseases.Methods RNA sequencing of 246 explanted liver samples and genome-wide genotyping was performed to identify single-nucleotide polymorphisms (SNPs) associated with liver expression of ANGPTL3. Genome-wide summary statistics of plasma protein levels of ANGPTL3 from the deCODE study (n = 35 359) were used. A total of 647 carriers of ANGPTL3 protein-truncating variants (PTVs) associated with lower plasma triglyceride levels were identified in the UK Biobank. Two-sample MR using SNPs that influence ANGPTL3 liver expression or ANGPTL3 plasma protein levels as exposure and cardiometabolic diseases as outcomes was performed (CAD, IS, heart failure, non-alcoholic fatty liver disease, acute pancreatitis, and type 2 diabetes). The impact of rare PTVs influencing plasma triglyceride levels on apoB levels and CAD was also investigated in the UK Biobank.Results In two-sample MR studies, common genetic variants influencing ANGPTL3 hepatic or blood expression levels of ANGPTL3 had a very strong effect on plasma triglyceride levels, a more modest effect on low-density lipoprotein cholesterol, a weaker effect on apoB levels, and no effect on CAD or other cardiometabolic diseases. In the UK Biobank, the carriers of rare ANGPTL3 PTVs providing lifelong reductions in median plasma triglyceride levels [-0.37 (interquartile range 0.41) mmol/L] had slightly lower apoB levels (-0.06 +/- 0.32 g/L) and similar CAD event rates compared with non-carriers (10.2% vs. 10.9% in carriers vs. non-carriers, P = .60).Conclusions PTVs influencing ANGPTL3 protein structure as well as common genetic variants influencing ANGPTL3 hepatic expression and/or blood protein levels exhibit a strong effect on circulating plasma triglyceride levels, a weak effect on circulating apoB levels, and no effect on ASCVD. Near-complete inhibition of ANGPTL3 function in patients with very elevated apoB levels may be required to reduce ASCVD risk. Structured Graphical Abstract ANGPTL3, angiopoietin-like protein-3; LDL, low-density lipoprotein; RNA, ribonucleic acid; SNP, single-nucleotide polymorphism.
Aims:Elevated lipoprotein(a) [Lp(a)] levels are associated with the risk of coronary artery disease (CAD) and calcific aortic valve stenosis (CAVS). Observational studies revealed that Lp(a) and C-reactive protein (CRP) levels, a biomarker of systemic inflammation, may jointly predict CAD risk. Whether Lp(a) and CRP levels also jointly predict CAVS incidence and progression is unknown. Methods and results:We investigated the association of Lp(a) with CAVS according to CRP levels in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk study (n = 18 226, 406 incident cases) and the UK Biobank (n = 438 260, 4582 incident cases), as well as in the ASTRONOMER study (n = 220), which assessed the haemodynamic progression rate of pre-existing mild-to-moderate aortic stenosis. In EPIC-Norfolk, in comparison to individuals with low Lp(a) levels (<50 mg/dL) and low CRP levels (<2.0 mg/L), those with elevated Lp(a) (>50 mg/dL) and low CRP levels (<2.0 mg/L) and those with elevated Lp(a) (>50 mg/dL) and elevated CRP levels (>2.0 mg/L) had a higher CAVS risk [hazard ratio (HR) = 1.86 (95% confidence intervals, 1.30-2.67) and 2.08 (1.44-2.99), respectively]. A comparable predictive value of Lp(a) in patients with vs. without elevated CRP levels was also noted in the UK Biobank. In ASTRONOMER, CAVS progression was comparable in patients with elevated Lp(a) levels with or without elevated CRP levels. Conclusion:Lp(a) predicts the incidence and possibly progression of CAVS regardless of plasma CRP levels. Lowering Lp(a) levels may warrant further investigation in the prevention and treatment of CAVS, regardless of systemic inflammation.
Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent disease with no specific drug therapy. High-throughput metabolomics present an unprecedented opportunity to identify biomarkers and potentially causal risk factors for NAFLD. Here, we determined the impact of 21 circulating metabolites, 17 lipids, and 132 lipoprotein particle characteristics on NAFLD combining prospective observational and two-sample Mendelian randomization (MR) analyses in 121,032 UK Biobank participants. We identified several metabolic factors associated with NAFLD risk in observational and MR analyses including triglyceride-rich and high-density lipoprotein particles composition, as well as the ratio of polyunsaturated fatty acids to total fatty acids. This study, is one of the largest to investigate incident NAFLD, provides concordant observational and genetic evidence that therapies aimed at reducing circulating triglycerides and increasing large HDL particles, as well as interventions aimed at increasing polyunsaturated fatty acid content may warrant further investigation into NAFLD prevention and treatment.
BACKGROUND & AIMS: Acute pancreatitis (AP) is a complex disease and the leading cause of gastrointestinal disease- related hospital admissions. Few therapeutic options exist for AP prevention. Blood proteins with causal evidence may represent promising drug targets, but few have been causally linked with AP. Our objective was to identify blood proteins linked with AP by combining genome-wide association meta -analysis and proteome-wide Mendelian randomization (MR) studies. METHODS: We performed a genome-wide associa-tion meta-analysis totalling 10,630 patients with AP and 844,679 controls and a series of inverse-variance weighted MR analyses using cis-acting variants on 4719 blood proteins from the deCODE study (N = 35,559) and 4979 blood pro-teins from the Fenland study (N = 10,708). RESULTS: The meta-analysis identified genome-wide significant variants (P <5 x 10-8) at 5 loci (ABCG5/8, TWIST2, SPINK1, PRSS2 and MORC4). The proteome-wide MR analyses identified 68 unique blood proteins that may causally be associated with AP, including 29 proteins validated in both data sets. Func-tional annotation of these proteins confirmed expression of many proteins in metabolic tissues responsible for digestion and energy metabolism, such as the esophagus, adipose tis-sue, and liver as well as acinar cells of the pancreas. Genetic colocalization and investigations into the druggable genome also identified potential drug targets for AP. CONCLUSIONS: This large genome-wide association study meta-analysis for AP identified new variants linked with AP as well as several blood proteins that may be causally associated with AP. This study provides new information on the genetic architecture of this disease and identified pathways related to AP, which may be further explored as possible therapeutic targets for AP.
Introduction: Elevated Lipoprotein(a) (Lp[a]) levels are strongly and linearly associated with coronary artery disease (CAD) and calcific aortic valve stenosis (CAVS). Observational studies in primary and secondary prevention settings revealed that Lp(a) and other CAD risk factors such as C-reactive protein (CRP) levels, a biomarker of systemic inflammation, may jointly predict CAD risk. Whether Lp(a) and CRP levels also jointly predict CAVS risk is unknown. Methods: We investigated the long-term associations of Lp(a) with CAD and CAVS according to CRP levels in the European Prospective Investigation Into Cancer and Nutrition (EPIC)-Norfolk study. Lp(a) and CRP levels were measured in 18,459 participants who were followed for 20 years. During the follow-up, 3915 and 418 participants had incident CAD and CAVS, respectively. Results: As presented in Figure 1, in comparison to individuals with low Lp(a) levels (<30 mg/dL) and low CRP levels (<2.0 mg/dL), those with elevated Lp(a) (>30 mg/dL) and low CRP levels (<2.0 mg/dL) and those with elevated Lp(a) (>30 mg/dL) and elevated CRP levels (>2.0 mg/dL) had a higher CAD risk (hazard ratio [HR] = 1.38 [95% CI, 1.28-1.49] and 1.93 [95% CI, 1.74-2.13] , respectively), and a higher CAVS risk (HR = 1.46 [95% CI, 1.08-1.98] and 1.87 [95% CI, 1.40-2.49], respectively). Conclusions: Results of this study confirm the joint association of high Lp(a) and CRP levels on incident CAD and extend these joint associations to valvular diseases such as CAVS. Lowering Lp(a) levels may warrant further investigation in the prevention of CAD and CAVS, especially in the context of systemic inflammation.
BackgroundLipoprotein(a) (Lp[a]), which consists of a low-density lipoprotein (LDL) bound to apolipoprotein(a), is one of the strongest genetic risk factors for atherosclerotic cardiovascular diseases. Few studies have performed hypothesis-free direct comparisons of the Lp(a) and the LDL proteomes. Our objectives were to compare the Lp(a) and the LDL proteomic profiles and to evaluate the effect of lifelong exposure to elevated Lp(a) or LDL cholesterol levels on the plasma proteomic profile.MethodsWe performed a label-free analysis of the Lp(a) and LDL proteomic profiles of healthy volunteers in a discovery (n = 6) and a replication (n = 9) phase. We performed inverse variance weighted Mendelian randomization to document the effect of lifelong exposure to elevated Lp(a) or LDL cholesterol levels on the plasma proteomic profile of participants of the INTERVAL study.ResultsWe identified 15 proteins that were more abundant on Lp(a) compared with LDL (serping1, pi16, itih1, itih2, itih3, pon1, podxl, cd44, cp, ptprg, vtn, pcsk9, igfals, vcam1, and ttr). We found no proteins that were more abundant on LDL compared with Lp(a). After correction for multiple testing, lifelong exposure to elevated LDL cholesterol levels was associated with the variation of 18 plasma proteins whereas Lp(a) did not appear to influence the plasma proteome.ConclusionsResults of this study highlight marked differences in the proteome of Lp(a) and LDL as well as in the effect of lifelong exposure to elevated LDL cholesterol or Lp(a) on the plasma proteomic profile.
Hepatokines are liver-derived proteins that may influence metabolic pathways such as insulin sensitivity. Recently, Sparc-related modular calcium-binding protein 1 (SMOC1) was identified as glucose-responsive hepatokine that is dysregulated in the setting of non-alcoholic fatty liver disease (NAFLD). While SMOC1 may influence glucose-insulin homeostasis in rodents, it is unknown if SMOC1 is influenced by NAFLD in humans. It is also unknown if SMOC1 is causally associated with metabolic and disease traits in humans. Therefore, we aimed to determine the effect of NAFLD on SMOC1 gene expression in the liver and aimed to explore the potential causal associations of SMOC1 levels with NAFLD, T2D, and glycemic traits in humans. Using an RNA sequencing dataset from a cohort of 216 patients with NAFLD, we assessed SMOC1 expression levels across the NAFLD spectrum. We performed a series of bidirectional inverse-variance weighted Mendelian randomization (MR) analyses on blood SMOC1 levels using two sources of genome-wide association studies (GWAS) (Fenland study, n = 10,708 and INTERVAL study, n = 3301). We utilized GWAS summary statistics for NAFLD in 8434 cases and 770,180 controls, as well as publicly available GWAS for type 2 diabetes (T2D), body mass index (BMI), waist-to-hip ratio (WHR), fasting blood insulin (FBI), fasting blood glucose (FBG), homeostatic Model Assessment of Insulin Resistance (HOMA-B and HOMA-IR), and hemoglobin A1c (HbA1C). We found that SMOC1 expression showed no significant differences across NAFLD stages. We also identified that the top single-nucleotide polymorphism associated with blood SMOC1 levels, was associated with SMOC1 gene expression in the liver, but not in other tissues. Using MR, we did not find any evidence that genetically predicted NAFLD, T2D, and glycemic traits influenced SMOC1 levels. We also did not find evidence that blood SMOC1 levels were causally associated with T2D, NAFLD, and glycemic traits. In conclusion, the hepatokine SMOC1 does not appear to be modulated by the presence of NAFLD and may not regulate glucose-insulin homeostasis in humans. Results of this study suggest that blood factors regulating metabolism in rodents may not always translate to human biology.
Lipoprotein(a) (Lp(a)) is one of the most important risk factors for the development of calcific aortic valve stenosis (CAVS). However, the mechanisms through which Lp(a) causes CAVS are currently unknown. Our objectives were to characterize the Lp(a) proteome and to identify proteins that may be differentially associated with Lp(a) in patients with versus without CAVS. Our second objective was to identify genes that may be differentially regulated by exposure to high versus low Lp(a) levels in explanted aortic valves from patients with CAVS. We isolated Lp(a) from the blood of 21 patients with CAVS and 22 volunteers and performed untargeted label-free analysis of the Lp(a) proteome. We also investigated the transcriptomic signature of calcified aortic valves from patients who underwent aortic valve replacement with high versus low Lp(a) levels (n = 118). Proteins involved in the protein activation cascade, platelet degranulation, leukocyte migration, and response to wounding may be associated with Lp(a) depending on CAVS status. The transcriptomic analysis identified genes involved in cardiac aging, chondrocyte development, and inflammation as potentially influenced by Lp(a). Our multi-omic analyses identified biological pathways through which Lp(a) may cause CAVS, as well as key molecular events that could be triggered by Lp(a) in CAVS development.