Derivation and validation of a predictive mortality model of in-hospital patients with Acinetobacter baumannii nosocomial infection or colonization.

PURPOSE: Acinetobacter baumannii (Ab) is a Gram-negative opportunistic bacterium responsible for nosocomial infections or colonizations. It is considered one of the most alarming pathogens due to its multi-drug resistance and due to its mortality rate, ranging from 34 to 44,5% of hospitalized patients. The aim of the work is to create a predictive mortality model for hospitalized patient with Ab infection or colonization. METHODS: A cohort of 140 sequentially hospitalized patients were randomized into a training cohort (TC) (100 patients) and a validation cohort (VC) (40 patients). Statistical bivariate analysis was performed to identify variables discriminating surviving patients from deceased ones in the TC, considering both admission time (T0) and infection detection time (T1) parameters. A custom logistic regression model was created and compared with models obtained from the "status" variable alone (Ab colonization/infection), SAPS II, and APACHE II scores. ROC curves were built to identify the best cut-off for each model. RESULTS: Ab infection status, use of penicillin within 90 days prior to ward admission, acidosis, Glasgow Coma Scale, blood pressure, hemoglobin and use of NIV entered the logistic regression model. Our model was confirmed to have a better sensitivity (63%), specificity (85%) and accuracy (80%) than the other models. CONCLUSION: Our predictive mortality model demonstrated to be a reliable and feasible model to predict mortality in Ab infected/colonized hospitalized patients.

Consensus document on diagnosis and management of familial hypercholesterolemia from the Italian Society for the Study of Atherosclerosis (SISA).

AIMS: Familial Hypercholesterolemia (FH) is a genetic disorder of lipoprotein metabolism that causes an increased risk of premature atherosclerotic cardiovascular disease (ASCVD). Although early diagnosis and treatment of FH can significantly improve the cardiovascular prognosis, this disorder is underdiagnosed and undertreated. For these reasons the Italian Society for the Study of Atherosclerosis (SISA) assembled a Consensus Panel with the task to provide guidelines for FH diagnosis and treatment. DATA SYNTHESIS: Our guidelines include: i) an overview of the genetic complexity of FH and the role of candidate genes involved in LDL metabolism; ii) the prevalence of FH in the population; iii) the clinical criteria adopted for the diagnosis of FH; iv) the screening for ASCVD and the role of cardiovascular imaging techniques; v) the role of molecular diagnosis in establishing the genetic bases of the disorder; vi) the current therapeutic options in both heterozygous and homozygous FH. Treatment strategies and targets are currently based on low-density lipoprotein cholesterol (LDL-C) levels, as the prognosis of FH largely depends on the magnitude of LDL-C reduction achieved by lipid-lowering therapies. Statins with or without ezetimibe are the mainstay of treatment. Addition of novel medications like PCSK9 inhibitors, ANGPTL3 inhibitors or lomitapide in homozygous FH results in a further reduction of LDL-C levels. LDL apheresis is indicated in FH patients with inadequate response to cholesterol-lowering therapies. CONCLUSION: FH is a common, treatable genetic disorder and, although our understanding of this disease has improved, many challenges still remain with regard to its identification and management.

2023 Update on European Atherosclerosis Society Consensus Statement on Homozygous Familial Hypercholesterolaemia: new treatments and clinical guidance.

This 2023 statement updates clinical guidance for homozygous familial hypercholesterolaemia (HoFH), explains the genetic complexity, and provides pragmatic recommendations to address inequities in HoFH care worldwide. Key strengths include updated criteria for the clinical diagnosis of HoFH and the recommendation to prioritize phenotypic features over genotype. Thus, a low-density lipoprotein cholesterol (LDL-C) >10 mmol/L (>400 mg/dL) is suggestive of HoFH and warrants further evaluation. The statement also provides state-of-the art discussion and guidance to clinicians for interpreting the results of genetic testing and for family planning and pregnancy. Therapeutic decisions are based on the LDL-C level. Combination LDL-C-lowering therapy-both pharmacologic intervention and lipoprotein apheresis (LA)-is foundational. Addition of novel, efficacious therapies (i.e. inhibitors of proprotein convertase subtilisin/kexin type 9, followed by evinacumab and/or lomitapide) offers potential to attain LDL-C goal or reduce the need for LA. To improve HoFH care around the world, the statement recommends the creation of national screening programmes, education to improve awareness, and management guidelines that account for the local realities of care, including access to specialist centres, treatments, and cost. This updated statement provides guidance that is crucial to early diagnosis, better care, and improved cardiovascular health for patients with HoFH worldwide.

APOC-III: a Gatekeeper in Controlling Triglyceride Metabolism.

PURPOSE OF REVIEW: Apolipoprotein C-III (ApoC-III) is a widely known player in triglyceride metabolism, and it has been recently recognized as a polyhedric factor which may regulate several pathways beyond lipid metabolism by influencing cardiovascular, metabolic, and neurological disease risk. This review summarizes the different functions of ApoC-III and underlines the recent findings related to its multifaceted pathophysiological role. RECENT FINDINGS: The role of ApoC-III has been implicated in HDL metabolism and in the development of atherosclerosis, inflammation, and ER stress in endothelial cells. ApoC-III has been recently considered an important player in insulin resistance mechanisms, lipodystrophy, diabetic dyslipidemia, and postprandial hypertriglyceridemia (PPT). The emerging evidence of the involvement of ApoC-III in the in the pathogenesis of Alzheimer's disease open the way to further study if modification of ApoC-III level slows disease progression. Furthermore, ApoC-III is clearly linked to cardiovascular disease (CVD) risk, and progression of coronary artery disease (CAD) as well as the calcification of aortic valve and recent clinical trials has pointed out the inhibition of ApoC-III as a promising approach to manage hypertriglyceridemia and prevent CVD. Several evidences highlight the role of ApoC-III not only in triglyceride metabolism but also in several cardio-metabolic pathways. Results from recent clinical trials underline that the inhibition of ApoC-III is a promising therapeutical strategy for the management of severe hypertriglyceridemia and in CVD prevention.

Consensus document on Lipoprotein(a) from the Italian Society for the Study of Atherosclerosis (SISA).

AIMS: In view of the consolidating evidence on the causal role of Lp(a) in cardiovascular disease, the Italian Society for the Study of Atherosclerosis (SISA) has assembled a consensus on Lp(a) genetics and epidemiology, together with recommendations for its measurement and current and emerging therapeutic approaches to reduce its plasma levels. Data on the Italian population are also provided. DATA SYNTHESIS: Lp(a) is constituted by one apo(a) molecule and a lipoprotein closely resembling to a low-density lipoprotein (LDL). Its similarity with an LDL, together with its ability to carry oxidized phospholipids are considered the two main features making Lp(a) harmful for cardiovascular health. Plasma Lp(a) concentrations vary over about 1000 folds in humans and are genetically determined, thus they are quite stable in any individual. Mendelian Randomization studies have suggested a causal role of Lp(a) in atherosclerotic cardiovascular disease (ASCVD) and aortic valve stenosis and observational studies indicate a linear direct correlation between cardiovascular disease and Lp(a) plasma levels. Lp(a) measurement is strongly recommended once in a patient's lifetime, particularly in FH subjects, but also as part of the initial lipid screening to assess cardiovascular risk. The apo(a) size polymorphism represents a challenge for Lp(a) measurement in plasma, but new strategies are overcoming these difficulties. A reduction of Lp(a) levels can be currently attained only by plasma apheresis and, moderately, with PCSK9 inhibitor treatment. CONCLUSIONS: Awaiting the approval of selective Lp(a)-lowering drugs, an intensive management of the other risk factors for individuals with elevated Lp(a) levels is strongly recommended.

Prevalence and predictive role of hypertriglyceridemia in statin-treated patients at very high risk: Insights from the START study.

BACKGROUND AND AIM: Elevated triglyceride (TG) levels seem to identify subjects at increased cardiovascular risk, independent of LDL-C levels. We sought to evaluate the predictive role of hypertriglyceridemia, defined as TG levels ≥150 mg/dl, in very high risk (VHR) patients with chronic coronary syndromes (CCS) treated with statins. METHODS AND RESULTS: Using the data from the STable Coronary Artery Diseases RegisTry (START) study, an Italian nationwide registry, we assessed the association between the TG levels and baseline clinical characteristics, pharmacological treatment and major adverse cardio-cerebrovascular events (MACCE) at 1 year in a large cohort of statin-treated patients at VHR. Of the 4751 consecutive patients with CCS enrolled in the registry and classified as VHR, 2652 (55.8%) had TG values available (mean 120.6 ± 54.9) and were treated with at least a statin at baseline: 2019 (76.1%) with TG < 150 and 633 (23.9%) with TG ≥ 150 mg/dl. At 1 year from enrolment, MACCE occurred in 168 (6.3%) patients, without differences between the two groups of TG (5.9 vs 7.6%; p = 0.14). At multivariable analysis, hypertriglyceridemia did not result as independent predictor of the MACCE (hazard ratio: 1.16; 95% confidence intervals: 0.82-1.64; p = 0.42). CONCLUSIONS: In the present large, nationwide cohort of consecutive CCS patients at VHR with statin-controlled LDL-C levels, hypertriglyceridemia was present in around 24% of cases and did not result as predictor of MACCE at 1 year. Further studies with a longer follow-up and larger sample size are needed to better define the prognostic role of TG levels when intensive LDL lowering therapies are used.

Clinical evaluation of bempedoic acid for the treatment of hyperlipidaemia.

Bempedoic acid (BA) is a novel first-in-class oral lipid-lowering therapy. BA has been approved by the European Medicinal Agency and Food and Drug Administration and has been commercialised throughout Europe since the end of 2020 as an add-on therapy in patients at high/very-high cardiovascular risk that are not at LDL-C goals with current lipid-lowering treatments. Recently, Italian lipid management experts gathered to discuss several open questions on BA characteristics and BArelated practical clinical issues. The panel permitted collection of its opinions in a ten Q&A format. AIM: The aim of this viewpoint is to discuss and answer several open questions on BA characteristics and BA-related practical clinical issues. DATA SYNTHESIS: The data includes main phase III studies, subanalysis and meta-analysis on BA. CONCLUSIONS: The panel permitted collection of its opinions in a ten Q&A format.

Lifestyle versus ezetimibe plus lifestyle in patients with biopsy-proven non-alcoholic steatohepatitis (LISTEN): A double-blind randomised placebo-controlled trial.

BACKGROUND AND AIMS: The LISTEN trial (ClinicalTrial.gov accession: NCT01950884) is a phase IV 52 weeks double blind parallel randomized controlled trial that evaluated the effect of ezetimibe plus lifestyle and dietary intervention (eze) vs. lifestyle and dietary intervention alone (placebo) on progression and complications of non-alcoholic steatohepatitis (NASH) evaluated by liver histology. METHODS AND RESULTS: Forty patients with NASH ascertained by histology were randomly allocated on the two study groups and subjected to a follow-up of 52 weeks, when they underwent a second liver biopsy. Main composite end point (EP) was based on the histological improvement in the severity of NASH. Thirty patients completed the study, Eze treatment was not able to improve the primary EP in comparison with placebo, with and odds ratio of 1.029 (0.18-6.38), p = 0.974. Treatment emergent adverse events registered during the study were not more prevalent in the treatment arm. CONCLUSIONS: ezetimibe administered on top of lifestyle and dietary modification failed to improve the histology of NASH in comparison with lifestyle and dietary modification alone. TRIAL ACCESSION NUMBER: ClinicalTrial.gov: NCT01950884.

A subgroup analysis of the ODYSSEY APPRISE study: Safety and efficacy of alirocumab in the Italian cohort.

BACKGROUND AND AIMS: ODYSSEY APPRISE trial evaluated efficacy and safety of alirocumab in 994 patients with hypercholesterolemia and high CV risk in a real-life setting. The aim of the present report is to detail on the Italian cohort enrolled and treated in the trial. METHODS AND RESULTS: The methodology of the of the multinational, single-arm, Phase 3b open-label ODYSSEY APPRISE (Clinicaltrials.gov: NCT02476006) has been previously reported. 255 Italian patients were enrolled and treated according to the trial protocol. Overall mean exposure to alirocumab was 83.3 ± 27.7 weeks. At week 12, LDL-C decreased by 51.3 ± 23.1% and this reduction was overall maintained for the duration of the study. A similar reduction was observed in patients with and without heterozygous familial hypercholesterolemia (HeFH 50.7% ± 23.9 vs. non-FH, 53.6% ± 19.6). LDL-C was reduced below 1.8 mmol/L and/or by ≥ 50% reduction from baseline in 62% of patients overall (61% in HeFH and 67% in non-FH). Alirocumab was similarly well tolerated in the Italian cohort as in the entire study population and the more common treatment emergent adverse events (TEAEs) were influenza, myalgia and nasopharyngitis. The incidence LDL-C levels <25 mg/dl and <15 mg/dl, was 8.2% and 2.9% respectively. CONCLUSION: The efficacy and safety of alirocumab in a real-life setting, in the Italian subgroup of patients are consistent with findings in the entire study population and confirm that alirocumab is a beneficial approach to further reduce LDL-C levels in patients at high CV risk on maximally tolerated conventional lipid lowering treatment. GOV IDENTIFIER: NCT02476006.

Triglyceride-rich lipoproteins and their remnants: metabolic insights, role in atherosclerotic cardiovascular disease, and emerging therapeutic strategies-a consensus statement from the European Atherosclerosis Society.

Recent advances in human genetics, together with a large body of epidemiologic, preclinical, and clinical trial results, provide strong support for a causal association between triglycerides (TG), TG-rich lipoproteins (TRL), and TRL remnants, and increased risk of myocardial infarction, ischaemic stroke, and aortic valve stenosis. These data also indicate that TRL and their remnants may contribute significantly to residual cardiovascular risk in patients on optimized low-density lipoprotein (LDL)-lowering therapy. This statement critically appraises current understanding of the structure, function, and metabolism of TRL, and their pathophysiological role in atherosclerotic cardiovascular disease (ASCVD). Key points are (i) a working definition of normo- and hypertriglyceridaemic states and their relation to risk of ASCVD, (ii) a conceptual framework for the generation of remnants due to dysregulation of TRL production, lipolysis, and remodelling, as well as clearance of remnant lipoproteins from the circulation, (iii) the pleiotropic proatherogenic actions of TRL and remnants at the arterial wall, (iv) challenges in defining, quantitating, and assessing the atherogenic properties of remnant particles, and (v) exploration of the relative atherogenicity of TRL and remnants compared to LDL. Assessment of these issues provides a foundation for evaluating approaches to effectively reduce levels of TRL and remnants by targeting either production, lipolysis, or hepatic clearance, or a combination of these mechanisms. This consensus statement updates current understanding in an integrated manner, thereby providing a platform for new therapeutic paradigms targeting TRL and their remnants, with the aim of reducing the risk of ASCVD.

New Frontiers in the Treatment of Homozygous Familial Hypercholesterolemia.

Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disorder. The most common cause is a mutation in both alleles of the gene encoding for the low-density lipoprotein (LDL) receptor, although other causative mutations have been identified. Complications of atherosclerotic cardiovascular disease are common in these patients; therefore, reducing the elevated LDL-cholesterol burden is critical in their management. Conventionally, this is achieved by patients initiating lipid-lowering therapy, but this can present challenges in clinical practice. Fortunately, novel therapeutic strategies have enabled promising innovations in HoFH treatment. This review highlights recent and ongoing studies examining new therapeutic options for patients with HoFH.

Left ventricular hypertrophy in chronic kidney disease: A diagnostic criteria comparison.

BACKGROUND AND AIMS: CKD patients have a high prevalence of LVH and this leads to an increase of cardiovascular risk. The aim of this study was to assess the prevalence of left ventricular hypertrophy (LVH) and left ventricular geometry in a group of 293 hypertensive patients with stage 2-5 chronic kidney disease (CKD), compared with 289 essential hypertensive patients with normal renal function. METHODS AND RESULTS: All patients underwent echocardiographic examination. Patients on stage 1 CKD, dialysis treatment, or with cardiovascular diseases were excluded. LVH was observed in 62.8% of patients with CKD and in 51.9% of essential hypertensive patients (P < 0.0001). We found increasingly higher left ventricular diameters, thicknesses, and mass from stage 2-5 CKD. Distribution of concentric and eccentric LVH was not very different between the two groups. However, after introducing mixed hypertrophy, the difference between the two groups group was disclosed (P = 0.027). Multiple regression analysis confirmed that the association between renal function and left ventricular mass (ß -0.287; P < 0.0001) was independent by potential confounders. Diastolic function was significantly worse in patients with CKD, especially in more advanced stages. CONCLUSION: Our study confirms that LVH is highly prevalent in patients with CKD, especially by using the most recent cut off; in this population, LVH is often characterized by the simultaneous increase of wall thicknesses and diameters with negative effects on diastolic function.

rs629301 CELSR2 polymorphism confers a ten-year equivalent risk of critical stenosis assessed by coronary angiography.

BACKGROUND AND AIMS: Novel genetic determinants associated with coronary artery disease (CAD) have been discovered by genome wide association studies. Variants encompassing the CELSR2- PSRC1-SORT1 gene cluster have been associated with CAD. This study is aimed to investigate the rs629301 polymorphism association with the extent of CAD evaluated by coronary angiography (CAG), and to evaluate its associations with an extensive panel of lipid and lipoprotein measurements in a large Italian cohort of 2429 patients. METHODS AND RESULTS: The patients were collected by four Intensive Care Units located in Palermo and Verona (Italy). Clinical Records were filed, blood samples were collected, lipids and apolipoproteins (apo) were measured in separate laboratories. CAD was defined by the presence of stenotic arteries (>50% lumen diameter) by CAG. The presence of CAD was associated with the rs629301 genotype. Patients with CAD were 78% and 73% (p = 0.007) of the T/T vs. T/G + G/G genotype carriers respectively. T/T genotype was also correlated with the number of stenotic arteries, with a 1.29 (1.04-1.61) risk to have a three-arteries disease. T/T genotype correlated with higher levels of LDL-, non-HDL cholesterol, apoB, apoE and apoCIII, and lower HDL-cholesterol. Logistic Regression confirmed that rs629301was associated with CAD independently from the common risk factors, with a risk similar to that conferred by ten years of age [odds ratios were 1.43 (1.04-1.96) and 1.39 (1.22-1.58) respectively]. CONCLUSIONS: rs629301 risk allele was independently associated with the extension and severity of CAD and positively with apoE and apoB containing lipoproteins.

Lack of phenotypic additive effect of familial defective apolipoprotein B3531 in familial hypercholesterolaemia.

Familial defective apolipoprotein (apo) B (FDB) and familial hypercholesterolaemia (FH) are the two common genetic conditions that cause hypercholesterolaemia. R3531C mutation of the APOB gene is a rare cause of FDB. Individuals with both FDB and FH are rare. A 51-year-old man with hypercholesterolaemia (11.4 mmol/L) and his family were studied. Low-density lipoprotein (LDL) receptor (LDLR) and APOB genes were analysed by direct sequencing. LDL of four subjects were studied in a fibroblast LDL receptor-binding displacement assay. We found a mutation of the LDLR gene (p.Y398X) in the proband and in four other family members: the p.R3531C APOB gene mutation was also found in the proband, his father and his children. The proband and his son were thus compound heterozygotes for both FH and FDB. Double heterozygotes did not show higher cholesterol levels compared to carriers of LDLR gene mutation alone. LDL from one of the carriers of the p.R3531C alone exhibited a binding ability, which was similar to a normal subject. This is the first report in Italy of the p.R3531C mutation, and our results show that this mutation has no effect in LDLR p.Y398X/APOB p.R3531C double heterozygotes.

NPC1L1 and ABCG5/8 induction explain synergistic fecal cholesterol excretion in ob/ob mice co-treated with PPAR-α and LXR agonists.

Reverse cholesterol transport (RCT) and transintestinal cholesterol efflux (TICE) are two important pathways for body cholesterol elimination. We studied these pathways in an animal model of diabetes and obesity (ob/ob) where HDL function is compromised as a result of hyperglycemia, low-grade inflammation and oxidative stress. Co-treatment of ob/ob mice with PPAR-α (fenofibrate) and LXR (T0901317) agonists increased fecal cholesterol by 12-fold; PPAR-α and LXR agonists individually showed 2.6- and 4.0-fold fecal cholesterol excretion, respectively. We investigated the mechanism of synergistic efficacy of PPAR-α and LXR agonists in fecal cholesterol excretion. LXR agonist and the combination of PPAR-α and LXR agonists had greater HDL-C elevation. Ex vivo cholesterol efflux showed correlation with the fecal cholesterol excretion but was not sufficient to explain 12-fold increases in the fecal cholesterol in the co-treated mice. Therefore, we examined TICE to explain the 12-fold increases in the fecal cholesterol. A strong positive correlation of fecal cholesterol with ATP binding cassette transporter G5 (ABCG5) and G8 and a negative correlation with NPC1L1 was observed. ABCG5, G8 and NPC1L1 are involved in intestinal cholesterol absorption. The extent of influence of PPAR-α and LXR agonists on RCT and TICE was distinctly different. PPAR-α agonist increased fecal cholesterol primarily by influencing TICE, while LXR agonist influenced fecal cholesterol excretion via both RCT and TICE mechanisms. Synergistic efficacy on fecal cholesterol excretion following co-treatment with PPAR-α and LXR agonists occurred through a combination of RCT, TICE, and the key enzyme in bile synthesis, cholesterol 7-α hydroxylase (cyp7a1). These results suggest that cholesterol efflux, biliary cholesterol excretion, and TICE collectively contributed to the 12-fold increases in the fecal cholesterol excretion in ob/ob mice co-treated with PPAR-α and LXR agonists.

Relationship of a Body Shape Index and Body Roundness Index with carotid atherosclerosis in arterial hypertension.

BACKGROUND AND AIMS: A Body Shape Index (ABSI) and Body Roundness Index (BRI) are two new anthropometric adiposity indices that have shown to be associated better than BMI with adipose abdominal tissue, with the onset of diabetes and the risk of premature death. Little is known about the influence of ABSI and BRI on subclinical vascular damage. The study was aimed to assess the relationship between ABSI and BRI with carotid atherosclerosis damage in subjects with arterial hypertension. METHODS AND RESULTS: A total of 468 patients with arterial hypertension (30-80 years old) were enrolled; adiposity indices were calculated (BMI, WC, ABSI, BRI) and carotid ultrasonographic examination was performed to detect atherosclerotic damage (IMT or atherosclerotic plaque). BRI, but not ABSI, was higher in subjects with IMT> 0.90 mm in comparison to those with a lower IMT (p < 0.001), whereas patients with carotid plaques showed higher values of ABSI (p = 0.001), as well as of BRI (p = 0.003). Linear regression analysis disclosed significant correlation of IMT with ABSI, BRI and BMI (all p < 0.001). In the multivariate analysis, BRI was independently correlated with cIMT (p = 0.015). On the contrary, ABSI did not show any independent association with cIMT. However, ABSI was strongly associated with carotid plaques in multiple logistic regression analysis after adjustment for potential confounding factors. When BRI or BMI replaced ABSI into the multivariate models, they did not show any independent correlation with carotid plaques. CONCLUSIONS: ABSI may be proposed as a better correlate of carotid atherosclerosis than the traditional measures of adiposity.

Polyvascular subclinical atherosclerosis in familial hypercholesterolemia: The role of cholesterol burden and gender.

BACKGROUND AND AIM: Heterozygous familial hypercholesterolemia (HeFH) is a genetic disease characterized by a heterogeneous phenotype. The assessment of cardiovascular (CV) risk is challenging for HeFH. Cholesterol burden (CB) allows to estimate the lifelong exposure to high levels of cholesterol. The aim of this study was to analyze the distribution of subclinical atherosclerosis and the relationship between atherosclerosis and the CB in a sample of HeFH patients, focusing on sex-related differences. METHODS AND RESULTS: 154 asymptomatic HeFH subjects underwent coronary-artery-calcium score (CACs) and Doppler ultrasound of carotid and femoral arteries. Yearly lipid profiles and HeHF history were obtained from patients' files in order to calculate total CB. Atherosclerotic burden was defined by the presence of CACs > 0 or by the presence of carotid or femoral plaque. Study population was stratified according to gender. The prevalence of CAC, carotid and femoral atherosclerosis was of 62%, 55% and 56%, respectively. Coronary district was the least involved in women, who had a higher prevalence in carotid atherosclerosis. When two vascular districts were affected, women had an increased prevalence of femoral and carotid atherosclerosis whereas men had a higher prevalence of coronary and femoral atherosclerosis. CB correlated to the presence of atherosclerosis in any of the three vascular districts with a significant increasing trend depending on the number of affected areas. CONCLUSIONS: A polyvascular atherosclerotic burden is found in asymptomatic HeFH patients. Gender differences in the territory distribution were observed. The early and lasting exposure to high cholesterol, as expressed by CB, is a major determinant of atherosclerotic burden.

Efficacy and safety of alirocumab in reducing lipids and cardiovascular events.

BACKGROUND: Alirocumab, a monoclonal antibody that inhibits proprotein convertase subtilisin-kexin type 9 (PCSK9), has been shown to reduce low-density lipoprotein (LDL) cholesterol levels in patients who are receiving statin therapy. Larger and longer-term studies are needed to establish safety and efficacy. METHODS: We conducted a randomized trial involving 2341 patients at high risk for cardiovascular events who had LDL cholesterol levels of 70 mg per deciliter (1.8 mmol per liter) or more and were receiving treatment with statins at the maximum tolerated dose (the highest dose associated with an acceptable side-effect profile), with or without other lipid-lowering therapy. Patients were randomly assigned in a 2:1 ratio to receive alirocumab (150 mg) or placebo as a 1-ml subcutaneous injection every 2 weeks for 78 weeks. The primary efficacy end point was the percentage change in calculated LDL cholesterol level from baseline to week 24. RESULTS: At week 24, the difference between the alirocumab and placebo groups in the mean percentage change from baseline in calculated LDL cholesterol level was -62 percentage points (P<0.001); the treatment effect remained consistent over a period of 78 weeks. The alirocumab group, as compared with the placebo group, had higher rates of injection-site reactions (5.9% vs. 4.2%), myalgia (5.4% vs. 2.9%), neurocognitive events (1.2% vs. 0.5%), and ophthalmologic events (2.9% vs. 1.9%). In a post hoc analysis, the rate of major adverse cardiovascular events (death from coronary heart disease, nonfatal myocardial infarction, fatal or nonfatal ischemic stroke, or unstable angina requiring hospitalization) was lower with alirocumab than with placebo (1.7% vs. 3.3%; hazard ratio, 0.52; 95% confidence interval, 0.31 to 0.90; nominal P=0.02). CONCLUSIONS: Over a period of 78 weeks, alirocumab, when added to statin therapy at the maximum tolerated dose, significantly reduced LDL cholesterol levels. In a post hoc analysis, there was evidence of a reduction in the rate of cardiovascular events with alirocumab. (Funded by Sanofi and Regeneron Pharmaceuticals; ODYSSEY LONG TERM ClinicalTrials.gov number, NCT01507831.).

Characterization of a mutant form of human apolipoprotein B (Thr26_Tyr27del) associated with familial hypobetalipoproteinemia.

We have previously identified a deletion mutant of human apoB [apoB (Thr26_Tyr27del)] in a subject with primary hypobetalipoproteinemia. The present study determined the effect of Thr26_Tyr27del mutation on apoB secretion using transfected McA-RH7777 cells. Transient or stable transfection of apoB-48 containing the Thr26_Tyr27del mutation showed drastically reduced secretion of the mutant as compared to wild-type apoB-48. No lipoproteins containing the mutant apoB-48 were secreted into the medium. Incubation of transfected cells in a lipid-rich medium in the presence of cycloheximide showed rapid turnover of cell-associated mutant apoB-48 as compared to that of wild-type apoB-48. Immunofluorescence experiments showed that the mutant apoB-48 was mostly localized in the endoplasmic reticulum. Treatment with the proteasomal inhibitor MG132 markedly attenuated the turnover of cell-associated mutant apoB-48, whereas treatment with inhibitors of autophagosomal/lysosomal function (e.g. 3-MA or ammonium chloride) had no effect. Taken together, these results indicated that the defective secretion of the Thr26_Tyr27del mutant was associated with increased intracellular degradation of apoB through the proteasome-dependent pathway.