Design and Baseline Characteristics of STEP-HFpEF Program Evaluating Semaglutide in Patients With Obesity HFpEF Phenotype.

BACKGROUND: The majority of patients with heart failure with preserved ejection fraction (HFpEF) have the obesity phenotype, but no therapies specifically targeting obesity in HFpEF exist. OBJECTIVES: The aim of this study was to describe the design and baseline characteristics of 2 trials of semaglutide, a glucagon-like peptide-1 receptor agonist, in patients with the obesity HFpEF phenotype: STEP-HFpEF (Semaglutide Treatment Effect in People with obesity and HFpEF; NCT04788511) and STEP-HFpEF DM (Semaglutide Treatment Effect in People with obesity and HFpEF and type 2 diabetes; NCT04916470). METHODS: Both STEP-HFpEF and STEP-HFpEF DM are international multicenter, double-blind, placebo-controlled trials that randomized adults with HFpEF and a body mass index ≥30 kg/m2 to once-weekly semaglutide at a dose of 2.4 mg or placebo. Participants were eligible if they had a left ventricular ejection fraction (LVEF) ≥45%; NYHA functional class II to IV; a Kansas City Cardiomyopathy Questionnaire (KCCQ)-Clinical Summary Score (CSS) <90 points; and ≥1 of the following: elevated filling pressures, elevated natriuretic peptides plus structural echocardiographic abnormalities, recent heart failure hospitalization plus ongoing diuretic use, and/or structural abnormalities. The dual primary endpoints are the 52-week change in the KCCQ-CSS and body weight. RESULTS: In STEP-HFpEF and STEP-HFpEF DM (N = 529 and N = 617, respectively), nearly half were women, and most had severe obesity (median body mass index of 37 kg/m2) with typical features of HFpEF (median LVEF of 57%, frequent comorbidities, and elevated natriuretic peptides). Most participants received diuretic agents and renin-angiotensin blockers at baseline, and approximately one-third were on mineralocorticoid receptor antagonists. Sodium-glucose cotransporter-2 inhibitor use was rare in STEP-HFpEF but not in STEP HFpEF DM (32%). Patients in both trials had marked symptomatic and functional impairments (KCCQ-CSS ∼59 points, 6-minute walking distance ∼300 m). CONCLUSIONS: In total, STEP-HFpEF program randomized 1,146 participants with the obesity phenotype of HFpEF and will determine whether semaglutide improves symptoms, physical limitations, and exercise function in addition to weight loss in this vulnerable group.

Naturally Occurring Variants in LRP1 (Low-Density Lipoprotein Receptor-Related Protein 1) Affect HDL (High-Density Lipoprotein) Metabolism Through ABCA1 (ATP-Binding Cassette A1) and SR-B1 (Scavenger Receptor Class B Type 1) in Humans.

OBJECTIVE: Studies into the role of LRP1 (low-density lipoprotein receptor-related protein 1) in human lipid metabolism are scarce. Although it is known that a common variant in LRP1 (rs116133520) is significantly associated with HDL-C (high-density lipoprotein cholesterol), the mechanism underlying this observation is unclear. In this study, we set out to study the functional effects of 2 rare LRP1 variants identified in subjects with extremely low HDL-C levels. APPROACH AND RESULTS: In 2 subjects with HDL-C below the first percentile for age and sex and moderately elevated triglycerides, we identified 2 rare variants in LRP1: p.Val3244Ile and p.Glu3983Asp. Both variants decrease LRP1 expression and stability. We show in a series of translational experiments that these variants culminate in reduced trafficking of ABCA1 (ATP-binding cassette A1) to the cell membrane. This is accompanied by an increase in cell surface expression of SR-B1 (scavenger receptor class B type 1). Combined these effects may contribute to low HDL-C levels in our study subjects. Supporting these findings, we provide epidemiological evidence that rs116133520 is associated with apo (apolipoprotein) A1 but not with apoB levels. CONCLUSIONS: This study provides the first evidence that rare variants in LRP1 are associated with changes in human lipid metabolism. Specifically, this study shows that LRP1 may affect HDL metabolism by virtue of its effect on both ABCA1 and SR-B1.

Lysosomal Cholesterol Hydrolysis Couples Efferocytosis to Anti-Inflammatory Oxysterol Production.

RATIONALE: Macrophages face a substantial amount of cholesterol after the ingestion of apoptotic cells, and the LIPA (lysosomal acid lipase) has a major role in hydrolyzing cholesteryl esters in the endocytic compartment. OBJECTIVE: Here, we directly investigated the role of LIPA-mediated clearance of apoptotic cells both in vitro and in vivo. METHODS AND RESULTS: We show that LIPA inhibition causes a defective efferocytic response because of impaired generation of 25-hydroxycholesterol and 27-hydroxycholesterol. Reduced synthesis of 25-hydroxycholesterol after LIPA inhibition contributed to defective mitochondria-associated membrane leading to mitochondrial oxidative stress-induced NLRP3 (NOD-like receptor family, pyrin domain containing) inflammasome activation and caspase-1-dependent Rac1 (Ras-related C3 botulinum toxin substrate 1) degradation. A secondary event consisting of failure to appropriately activate liver X receptor-mediated pathways led to mitigation of cholesterol efflux and apoptotic cell clearance. In mice, LIPA inhibition caused defective clearance of apoptotic lymphocytes and stressed erythrocytes by hepatic and splenic macrophages, culminating in splenomegaly and splenic iron accumulation under hypercholesterolemia. CONCLUSIONS: Our findings position lysosomal cholesterol hydrolysis as a critical process that prevents metabolic inflammation by enabling efficient macrophage apoptotic cell clearance.