👤 Fotios Barkas

Oxidative modification of apolipoprotein B-100 (apoB) containing particles and subsequent immune responses contribute to the pathogenesis of atherosclerosis. Circulating IgG and IgM apoB-containing immune complexes (apoB-IC) and autoantibodies to a malondialdehyde mimotope (anti-MDA-mimotope) serve as biomarkers of oxidative stress and immune activation in atherosclerotic cardiovascular disease. Elevated lipoprotein(a) [Lp(a)] is associated with increased oxidative burden and immune activation. To investigate the effect of lipid-lowering medications on IgG and IgM apoB-IC and IgG and IgM autoantibodies to an MDA-mimotope in individuals with elevated lipoprotein(a) [Lp(a)] concentrations. In this prospective study, patients (n = 70) with Lp(a) levels ≥ 75 nmol/L were assigned to 3 treatment regimens according to current guidelines: high-intensity statin monotherapy (n = 28), ezetimibe added to high-intensity statin (n = 31) and proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) added to high-intensity statin plus ezetimibe (n = 11). IgG and IgM apoB-IC and IgG and IgM anti-MDA-mimotope were measured at baseline and 3 months after treatment initiation. Patients had a mean age of 51 ± 15 years and 40% were male. Significant reductions in IgG apoB-IC levels were observed following treatment with high-intensity statins, add-on ezetimibe and add-on PCSK9i (by 18.3%, 17.5% and 25.5%, respectively, all p < 0.05). No significant changes in IgM apoB-IC, or IgG and IgM anti-MDA-mimotope levels were observed in any treatment group. In individuals with Lp(a) levels ≥ 75 nmol/L, high-intensity statins, add-on ezetimibe and add-on PCSK9i reduced IgG apoB-IC but did not affect IgM apoB-IC, or IgG and IgM anti-MDA-mimotope levels. The clinical significance of these findings warrants further investigation. Show less

This study investigated the relationship between apolipoprotein B (apoB), "excess apoB" (apoB beyond low-density lipoprotein cholesterol (LDL-C)), and apoB/apolipoprotein A1 (apoA1) ratio with 20-year atherosclerotic cardiovascular disease (ASCVD) incidence, using an age- and sex-specific approach. In 2002, a cohort of 3042 adults, free of cardiovascular disease (CVD) residing in the greater Athens area (Greece) was recruited. A 20-year follow-up was conducted in 2022, comprising of 2169 participants, of whom 1988 had complete data for CVD incidence. Cox proportional hazards models were used to assess the association of apoB, excess apoB, and apoB/apoA1 with 20-year ASCVD risk and residual risk (events not predicted by standard factors). Older participants and males had higher levels of apoB, excess apoB, and apoB/apoA1. In the overall cohort, only apoB was significantly associated with ASCVD risk (hazard ratio (HR), 1.006; p = 0.003). However, age- and sex-dependent associations were observed as apoB, excess apoB, and apoB/apoA1 significantly predicted increased ASCVD incidence only in males under 40 years (HR 1.025, p = 0.005; 1.052, p = 0.003; 1.396, p = 0.002; respectively). Significant associations were observed with residual ASCVD risk in the overall cohort, with the most pronounced associations seen in males under 40 (HR 1.023, p = 0.001; 1.039, p < 0.001; 1.285, p = 0.002; respectively). The association of apoB, excess apoB, and apoB/apoA1 with long-term ASCVD incidence and residual risk demonstrates age- and sex-dependent variations, with younger males showing elevated risk, highlighting the value of these markers beyond traditional risk factors and emphasizing the need for age- and sex-specific considerations in ASCVD risk assessment. Show less

Elevated lipoprotein(a) [Lp(a)] is a common risk factor for cardiovascular disease (CVD) affecting ∼1.4 billion people globally, with novel treatments under development. Guidelines recommend one-lifetime measurement, yet <1% are tested. Population-wide screening faces cost and implementation challenges. We developed a machine learning (ML) model to help prioritise patients for Lp(a) testing. Ethnicity-calibrated ML models were developed to identify individuals with elevated Lp(a) in UK Biobank. Participants ≥37 years old (N=438,579) were split into feature importance/selection(20%), derivation(60%), and validation(20%) datasets. Performances across risk-enhancing Lp(a) thresholds recommended by clinical guidelines (90, 125, 430 nmol/L) or entry criteria for ongoing Lp(a)-lowering trials (150, 175, 200 nmol/L) were evaluated. External validation was conducted in NHANES III. Screening one million people using a universal approach would identify 222,717 cases above 90 nmol/L and 1950 above 430 nmol/L. In contrast, applying ML-targeted testing using the same number of tests would identify 280,899 (+26%; 95%CI:20-28%) and 6881 (+253%; 95%CI:192-310%) cases, respectively. At the thresholds of 125, 150, 175, and 200 nmol/L, yield increases were 38% (95%CI:35-40%), 51% (95%CI:47-54%), 59% (95%CI:55-63%), and 66% (95%CI:61-71%). Across thresholds 90-430 nmol/L, ML-targeted testing (Number Needed to Screen [NNS] 3.6-145, AUC 0.61-0.84) required 21%-72% fewer tests to identify one million cases. NHANES III validation demonstrated similar performance. Top 4 predictors included age, height (proxy for sex), total cholesterol and statin use. A ML-guided approach to prioritise testing for elevated Lp(a) would require fewer tests to identify those above risk-enhancing thresholds or potentially eligible for emerging therapies, offering a scalable interim compromise between the low current testing rates and universal screening aspirations. Show less

Oxidized phospholipids (OxPLs) are bound to apolipoprotein B-100 (OxPL-apoB) and apolipoprotein(a) [OxPL-apo(a)] and are present freely within the phospholipid shell of apoB-containing lipoproteins. OxPLs have been linked with the pro-inflammatory properties of lipoprotein(a) [Lp(a)]. OxPLs carried on plasminogen (OxPL-PLG) may extend the time to fibrinolysis. To evaluate the effect of lipid-lowering medications on OxPLs levels in individuals with elevated Lp(a) concentrations. In this prospective study, patients (n = 70) with Lp(a) levels ≥75 nmol/L were assigned to 3 treatment regimens according to current guidelines: high-intensity statin monotherapy (n = 28), ezetimibe added to high-intensity statin (n = 31) and proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) added to high-intensity statin plus ezetimibe (n = 11). Follow-up duration was 3 months. Patients had a mean age of 51 ± 15 years, 40 % were male, 39 % were diagnosed with familial hypercholesterolemia, 16 % had atherosclerotic cardiovascular disease, and 36 %, 33 % and 15 % were at very high, high, and moderate cardiovascular risk, respectively. Lp(a) levels did not change significantly with high-intensity statin and add-on ezetimibe but significantly decreased with add-on PCSK9i treatment. OxPL-apoB and OxPL-apo(a) significantly increased, while OxPL-PLG significantly decreased with both high-intensity statin and add-on ezetimibe. Add-on PCSK9i treatment was associated with no significant changes in OxPL-apoB, OxPL-apo(a) and OxPL-PLG levels. Among patients with elevated Lp(a), both high-intensity statin and add-on ezetimibe significantly increased OxPL-apoB and OxPL-apo(a) levels, while significantly decreased OxPL-PLG levels. Add-on PCSK9i had no significant effect on OxPLs levels. The clinical implications of these findings should be further explored. Show less

To quantify international variations in lipid-lowering therapies (LLT) use among patients with coronary heart disease (CHD) and attainment of European guideline-recommended lipid goals. INTERASPIRE is an observational study (2020-23) covering 14 countries from all WHO regions. Patients (18-79 years) hospitalized in the preceding 6-36 months with CHD were invited for standardized interviews and examination, with central laboratory analyses for low-density lipoprotein cholesterol (LDL-C), non-HDL-C, and apolipoprotein B (apoB). Valid lipid data meeting quality control standards were available from 13 countries. Lipid goals followed the 2019 guidelines of the European Atherosclerosis Society and the European Society of Cardiology: LDL-C < 1.4 mmol/L, non-HDL-C < 2.2 mmol/L, and apoB <65 mg/dL.Among 4061 patients (78.8% male, mean age 60.3 years), between index event and interview, 66.3% had no change in treatment intensity. LLT use at interview was largely statin monotherapy: 49.6% high-intensity (inter-country range 5.3%-77.3%) and 24.1% low/moderate-intensity (inter-country range 5.1%-70.1%). Otherwise, 12.2% (inter-country range 0.2%-41.1%) were on combination therapy, and 12.7% on no LLT (inter-country range 3.5%-36.7%). Goal attainment for LDL-C was 17.5%. Corresponding non-HDL-C and apoB goals were achieved by 29.9% and 29.2%, respectively. Higher-income countries (defined by the World Bank's 2024-25 classification of income levels) did better in goal attainment than lower-middle-income countries. In this international study, contemporary lipid goals were not achieved in most CHD patients, with lower-middle-income countries having the worst goal attainment. Contributory factors include absence of any LLT use, low use of combinations and a failure to up-titrate LLT to achieve guideline targets. Show less

A strong correlation exists between low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), and apolipoprotein B100 (apoB). However, evidence suggests that LDL-C and non-HDL-C may underestimate apoB, potentially obscuring residual cardiovascular risk. Furthermore, interactions between apoB and lipoprotein(a) are implicated in atherogenesis. This study sought to determine whether discordance between apoB, LDL-C, non-HDL-C, or lipoprotein(a) is associated with 20-year atherosclerotic cardiovascular disease (ASCVD) risk within a cohort of apparently healthy adults. A cohort of 3042 CVD-free adults residing in greater Athens, Greece, was recruited in 2002. A 20-year follow-up was conducted in 2022, comprising n = 2169 participants, of which n = 1988 had complete data for cardiovascular disease incidence. Discordance between biomarkers was defined based on recommended lipid thresholds. Cox proportional hazards models were used to assess the association between discordant/concordant biomarker pairs and 20-year ASCVD risk. ApoB strongly correlated with LDL-C and non-HDL-C, though concordance was limited. Increased 20-year ASCVD cumulative incidence with elevated apoB levels, beyond LDL-C, non-HDL-C, and lipoprotein(a). Discordance analysis revealed that elevated apoB independently predicted increased 20-year ASCVD risk, regardless of non-HDL-C and lipoprotein(a). However, this effect was observed only on concomitantly elevated LDL-C levels. Incorporating apoB into the assessment of traditional modifiable risk factors elucidated part of the previously residual 20-year ASCVD risk, especially in individuals with elevated LDL-C, non-HDL-C, or lipoprotein(a) levels. ApoB may be a superior biomarker for assessing long-term ASCVD risk, indicating that apoB-containing lipoprotein particle number, rather than cholesterol content, is a more robust predictor of ASCVD risk. Show less

Familial hypercholesterolemia (FH), while highly prevalent, is a significantly underdiagnosed monogenic disorder. Improved detection could reduce the large number of cardiovascular events attributable to poor case finding. We aimed to assess whether machine learning algorithms outperform clinical diagnostic criteria (signs, history, and biomarkers) and the recommended screening criteria in the United Kingdom in identifying individuals with FH-causing variants, presenting a scalable screening criteria for general populations. Analysis included UK Biobank participants with whole exome sequencing, classifying them as having FH when (likely) pathogenic variants were detected in their Our machine learning-derived model provides a higher pretest probability of identifying individuals with a molecular diagnosis of FH compared with current approaches. This provides a promising, cost-effective scalable tool for implementation into electronic health records to prioritize potential FH cases for genetic confirmation. Show less