👤 J L Januzzi

Obicetrapib is a potent, selective cholesteryl ester transfer protein (CETP) inhibitor that significantly lowers low-density lipoprotein cholesterol (LDL-C). Additive reductions in LDL-C occur when obicetrapib is combined with ezetimibe. The impact of obicetrapib and ezetimibe fixed-dose combination (FDC) on coronary plaque burden is unknown. Favorable changes in noncalcified coronary atherosclerotic plaque volume (NCPV) may indicate a potential beneficial effect on atherosclerotic cardiovascular disease (ASCVD) events. REMBRANDT is a placebo-controlled, double-blind, randomized trial designed to assess the efficacy of obicetrapib and ezetimibe FDC on coronary plaque burden. Individuals aged 45 years or older with ASCVD (imaging evidence of vascular disease or clinically manifested ASCVD) and an LDL-C of ≥70 mg/dL despite maximally tolerated lipid-modifying therapy are eligible to participate. Eligible participants (N = 300) will be randomized in a 1:1 ratio to obicetrapib 10 mg and ezetimibe 10 mg FDC once daily or placebo tablet once daily. The primary efficacy outcome of REMBRANDT is percent change in total NCPV from baseline to 18 months as assessed by coronary computed tomographic angiography (CCTA). Secondary endpoints include absolute change in total NCPV, percent and absolute change in NCPV in the most diseased coronary segment, percent change in LDL-C, and change in perivascular fat attenuation index from baseline to 18 months. The REMBRANDT trial will determine whether the favorable effects of obicetrapib and ezetimibe FDC on LDL-C translate to a reduction in coronary plaque burden as a potential mechanism for ASCVD risk reduction. NCT06305559. Show less

Both lipoprotein(a) [Lp(a)] and peripheral artery disease (PAD) are associated with ischaemic events. We sought to assess the association between Lp(a) and major adverse cardiovascular events (MACE) and major lower extremity events (MALE) among patients with baseline PAD. The Mass General Brigham (MGB) Lp(a) registry includes all individuals with Lp(a) measured at two tertiary care centres from 2000 to 2019. Those with PAD were grouped according to Lp(a) percentile: 1st-25th [Q1, Lp(a) ≤ 14 nmol/L], 26th-50th (Q2, 14-<42 nmol/L), 51st-75th (Q3, 42-<132 nmol/L), and 76th-100th (Q4, 132-855 nmol/L). Outcomes were MACE [composite of cardiovascular (CV) death, myocardial infarction, or coronary revascularization] and MALE (composite of peripheral revascularization, acute limb ischaemia, or major lower extremity amputation). Cox proportional hazard modelling was used to assess the association between Lp(a) and the outcomes of interest after adjusting for traditional risk factors. Among 3757 individuals with PAD [39% female, median age 68 (IQR: 58-77)], individuals with Lp(a) levels in the third and fourth quartiles had a 24 and 30% increased hazard of MACE, respectively [adj. hazard ratio (HR): 1.24, P = 0.005; adj. HR: 1.30, P = 0.001] when compared with those in the first quartile. Individuals in the fourth quartile had a 19% greater hazard of MALE (adj. HR: 1.19, P = 0.043). Elevated Lp(a) in patients with PAD was associated with an increased risk of both MACE and MALE. Accordingly, measurement of Lp(a) may convey important prognostic value and allow for further risk stratification within this high-risk population. Show less

The roles of lipoprotein(a) [Lp(a)] and related oxidized phospholipids (OxPLs) in the development and progression of coronary disease is known, but their influence on extracoronary vascular disease is not well-established. We sought to evaluate associations between Lp(a), OxPL apolipoprotein B (OxPL-apoB), and apolipoprotein(a) (OxPL-apo(a)) with angiographic extracoronary vascular disease and incident major adverse limb events (MALEs). Four hundred forty-six participants who underwent coronary and/or peripheral angiography were followed up for a median of 3.7 years. Lp(a) and OxPLs were measured before angiography. Elevated Lp(a) was defined as ≥150 nmol/L. Elevated OxPL-apoB and OxPL-apo(a) were defined as greater than or equal to the 75th percentile (OxPL-apoB ≥8.2 nmol/L and OxPL-apo(a) ≥35.8 nmol/L, respectively). Elevated Lp(a) had a stronger association with the presence of extracoronary vascular disease compared to OxPLs and was minimally improved with the addition of OxPLs in multivariable models. Compared to participants with normal Lp(a) and OxPL concentrations, participants with elevated Lp(a) levels were twice as likely to experience a MALE (odds ratio: 2.14, 95% confidence interval: 1.03, 4.44), and the strength of the association as well as the C statistic of 0.82 was largely unchanged with the addition of OxPL-apoB and OxPL-apo(a). Elevated Lp(a) and OxPLs are risk factors for progression and complications of extracoronary vascular disease. However, the addition of OxPLs to Lp(a) does not provide additional information about risk of extracoronary vascular disease. Therefore, Lp(a) alone captures the risk profile of Lp(a), OxPL-apoB, and OxPL-apo(a) in the development and progression of atherosclerotic plaque in peripheral arteries. Show less

Concentrations of circulating apolipoproteins are strongly linked to risk for coronary artery disease (CAD). The relative importance of the additional knowledge of apolipoprotein concentrations within specific lipoprotein species for CAD risk prediction is limited. This study sought to evaluate the performance of a high-density lipoprotein (HDL) apolipoproteomic score, based on targeted mass spectrometry of HDL-associated apolipoproteins, for the detection of angiographic CAD and outcomes. HDL-associated apolipoprotein (apo) A-1, apoC-1, apoC-2, apoC-3, and apoC-4 were measured in 943 participants without prevalent myocardial infarction (MI) referred for coronary angiography in the CASABLANCA (Catheter Sampled Blood Archive in Cardiovascular Diseases) study. A composite HDL apolipoproteomic score (pCAD) was associated with likelihood of obstructive CAD (≥70% lesion in ≥1 vessel) and with incident cardiovascular outcomes over 4-year follow-up. There were 587 (62.2%) patients with coronary stenosis. The pCAD score was associated with the presence of obstructive CAD (odds ratio: 1.39; 95% confidence interval [CI]: 1.14 to 1.69; p < 0.001), independently of conventional cardiovascular risk factors including circulating plasma apoA-1 and apoB. The C-index for pCAD was 0.63 (95% CI: 0.59 to 0.67) for the presence of obstructive CAD. Although pCAD was not associated with cardiovascular mortality among all individuals (hazard ratio: 1.24; 95% CI: 0.93 to 1.66; p = 0.15), there was evidence of association for individuals with obstructive CAD (hazard ratio: 1.48; 95% CI: 1.07 to 2.05; p = 0.019). An HDL apolipoproteomic score is associated with the presence of CAD, independent of circulating apoA-1 and apoB concentrations and other conventional cardiovascular risk factors. Among individuals with CAD, this score may be independently associated cardiovascular death. (The CASABLANCA Study: Catheter Sampled Blood Archive in Cardiovascular Diseases [CASABLANCA]; NCT00842868). Show less

In this report we present the genomic, cDNA, and predicted protein sequences for mouse apolipoproteins A-I and CIII, as well as sequence comparisons with other species. The genes for these apolipoproteins are within 2.5 kb of each other and convergently transcribed. The almost 9 kb of genomic sequence presented extends from 1298 bp 5' to the apolipoprotein A-I (Apoa-1) gene to 1249 bp 5' to the apolipoprotein CIII (Apoc-3) gene. The mouse Apoa-1 gene is 1.76 kb in length with four exons and three introns. The 5' flanking region contains TATA and CCAAT box sequences, an interferon responsive element homology, and potential binding sites for transcription factors CTF/NF1 and HNF4. Translation of the cDNA predicts that the mouse Apoa-1 primary transcript is 264 amino acids. The mouse Apoc-3 gene is 2.2 kb in length and also consists of four exons and three introns. The 5' flanking region contains TATA and CCAAT box sequences, RXR-1 and ARP-1 binding sites, and potential binding sites for transcription factors HNF4, NFkB, AP-1, and CTF/NF1. Translation of the cDNA predicts that the mouse Apoc-3 primary transcript is 99 amino acids. The clustering and genomic organization of the mouse Apoa-1 and Apoc-3 genes are similar to those of the rat and human genes. Significant sequence homologies between species exist for the proximal promoter and exonic regions of each gene, but not for the intronic or intergenic regions.(ABSTRACT TRUNCATED AT 250 WORDS) Show less