Established and Emerging Nucleic Acid Therapies for Familial Hypercholesterolemia.

Familial hypercholesterolemia (FH) is a genetic disease that leads to elevated low-density lipoprotein cholesterol levels and risk of coronary heart disease. Current therapeutic options for FH remain relatively limited and only partially effective in both lowering low-density lipoprotein cholesterol and modifying coronary heart disease risk. The unique characteristics of nucleic acid therapies to target the underlying cause of the disease can offer solutions unachievable with conventional medications. DNA- and RNA-based therapeutics have the potential to transform the care of patients with FH. Recent advances are overcoming obstacles to clinical translation of nucleic acid-based medications, including greater stability of the formulations as well as site-specific delivery, making gene-based therapy for FH an alternative approach for treatment of FH.

Asymptomatic Intracranial Artery Stenosis/Occlusion in Heterozygous Familial Hypercholesterolemia: Its Frequency and Implications for Cerebrovascular and Cardiovascular Events.

BACKGROUND: The atherogenic characteristics of heterozygous familial hypercholesterolemia (HeFH) increase the risk of premature atherosclerotic cardiovascular disease including not only coronary artery disease but ischemic stroke. Asymptomatic intracranial artery stenosis/occlusion (IASO) is a major cause of ischemic stroke, but it has not yet been fully characterized in patients with HeFH. METHODS AND RESULTS: This study analyzed 147 clinically diagnosed subjects with HeFH who underwent magnetic resonance imaging/magnetic resonance angiography imaging for evaluation of IASO (≥50% diameter stenosis). Major adverse cerebrovascular and cardiovascular events (cardiac death, ischemic stroke, and acute coronary syndrome) were compared in patients with HeFH with and without asymptomatic IASO. Asymptomatic IASO was observed in 13.6% of patients with HeFH. The untreated low-density lipoprotein cholesterol level (240±95 versus 244±75 mg/dL; P=0.67) did not differ between the 2 groups. Despite the use of lipid-lowering therapies (statin, P=0.71; high-intensity statin, P=0.81; ezetimibe, P=0.33; proprotein convertase subxilisin/kexin type 9 inhibitor, P=0.39; low-density lipoprotein apheresis, P=0.14), on-treatment low-density lipoprotein cholesterol level in patients with both HeFH and IASO was still suboptimally controlled (97±62 versus 105±50 mg/dL; P=0.17), accompanied by a higher triglyceride level (median, 109 versus 79 mg/dL; P=0.001). During the 12.4-year observational period (interquartile range, 6.2-24.6 years), asymptomatic IASO exhibited a 4.04-fold greater likelihood of experiencing a major adverse cardiovascular event (95% CI, 1.71-9.55; P=0.001) in patients with HeFH. This increased risk of a major adverse cardiovascular event was consistently observed in a multivariate Cox proportional hazards model adjusting clinical characteristics (hazard ratio, 4.32 [95% CI, 1.71-10.9]; P=0.002). CONCLUSIONS: A total of 13.6% of Japanese subjects with HeFH presented with asymptomatic IASO. Despite lipid-lowering therapies, patients with both HeFH and IASO more likely had elevated risk of cerebrovascular and cardiovascular events. Our findings highlight asymptomatic IASO as a phenotypic feature of HeFH-related atherosclerosis, which ultimately affects future outcomes.

Lipid Disorders and Pregnancy.

Practicing endocrinologists are likely to confront 2 major issues that occur with dyslipidemias during pregnancy. The most dramatic is the development of severe hypertriglyceridemia leading to acute pancreatitis. The second is the approach to treatment of familial hypercholesterolemia, a common genetic disorder. This article reviews the normal physiology and the pathophysiology of lipoproteins that occurs with pregnancy and then discusses the approaches to prevention and/or treatment of dyslipidemia in pregnancy with a focus on lifestyle and acceptable drug therapies.

A Japanese Case of Familial Hypercholesterolemia with a Protein-truncating Variant in LDLR and a PCSK9 Variant without Significant Atherosclerosis but Showing Remarkable Achilles Tendon Thickening.

The patient was a 54-year-old woman with familial hypercholesterolemia and remarkable Achilles tendon thickening. At 20 years old, the patient had a total cholesterol level of approximately 300 mg/dL. She started receiving rosuvastatin (5 mg/day) for low-density lipoprotein cholesterol (LDL-C) 235 mg/dL at 42 years old, which was increased to 10 mg/day at 54 years old, decreasing her serum LDL-C level to approximately 90 mg/dL. The serum Lp (a) level was 9 mg/dL. A computed tomography coronary angiogram showed no significant stenosis. Next-generation sequencing revealed a frameshift variant in LDL receptor (LDLR) (heterozygous) and a missense variant in proprotein convertase subtilisin/kaxin type 9 (PCSK9) (heterozygous). Continued statin therapy, in addition to low Lp (a) and female sex, can help prevent cardiovascular disease.

Emerging therapies for refractory hypercholesterolemia: a narrative review.

Refractory hypercholesterolemia (RH) is characterized by the failure of patients to achieve therapeutic targets for low-density lipoprotein-cholesterol (LDL-C) despite receiving maximal tolerable doses of standard lipid-lowering treatments. It predominantly impacts individuals with familial hypercholesterolemia (FH), thereby elevating the risk of cardiovascular complications. The prevalence of RH is now recognized to be substantially greater than previously thought. This review provides a comprehensive insight into current and emerging therapies for RH patients, including groundbreaking genetic-based therapeutic approaches. The review places emphasis on the dependency of therapies on low-density lipoprotein receptors (LDLRs) and highlights the critical role of considering LDLR activity in RH patients for individualization of the treatment.

Refractory hypercholesterolemia (RH) is a condition where patients are unable to get below target levels of 'bad' cholesterol despite receiving maximum doses of standard treatments. It is commonly present in those with a genetic disorder, called familial hypercholesterolemia (FH), known to increase the risk of heart complications. RH's prevalence is now understood to be higher than previously believed and this review offers insights into current and emerging therapies for RH, including genetic-based treatments. It stresses the importance of the mechanistic pathways behind cholesterol clearance, particularly low-density lipoprotein receptor (LDLR) activity, in RH treatment customization.

Evinacumab in homozygous familial hypercholesterolaemia: long-term safety and efficacy.

BACKGROUND AND AIMS: Homozygous familial hypercholesterolaemia (HoFH) is a rare genetic disorder characterized by severely elevated LDL cholesterol (LDL-C) and premature atherosclerotic cardiovascular disease. In the pivotal Phase 3 HoFH trial (NCT03399786), evinacumab significantly decreased LDL-C in patients with HoFH. This study assesses the long-term safety and efficacy of evinacumab in adult and adolescent patients with HoFH. METHODS: In this open-label, single-arm, Phase 3 trial (NCT03409744), patients aged ≥12 years with HoFH who were evinacumab-naïve or had previously received evinacumab in other trials (evinacumab-continue) received intravenous evinacumab 15 mg/kg every 4 weeks with stable lipid-lowering therapy. RESULTS: A total of 116 patients (adults: n = 102; adolescents: n = 14) were enrolled, of whom 57 (49.1%) were female. Patients were treated for a median (range) duration of 104.3 (28.3-196.3) weeks. Overall, treatment-emergent adverse events (TEAEs) and serious TEAEs were reported in 93 (80.2%) and 27 (23.3%) patients, respectively. Two (1.7%) deaths were reported (neither was considered related to evinacumab). Three (2.6%) patients discontinued due to TEAEs (none were considered related to evinacumab). From baseline to Week 24, evinacumab decreased mean LDL-C by 43.6% [mean (standard deviation, SD), 3.4 (3.2) mmol/L] in the overall population; mean LDL-C reduction in adults and adolescents was 41.7% [mean (SD), 3.2 (3.3) mmol/L] and 55.4% [mean (SD), 4.7 (2.5) mmol/L], respectively. CONCLUSIONS: In this large cohort of patients with HoFH, evinacumab was generally well tolerated and markedly decreased LDL-C irrespective of age and sex. Moreover, the efficacy and safety of evinacumab was sustained over the long term.

Association Between Patient Sex and Familial Hypercholesterolemia and Long-Term Cardiovascular Risk Factor Management 5 Years After Acute Coronary Syndrome.

BACKGROUND: Long-term control of cardiovascular risk factors after acute coronary syndrome (ACS) is the cornerstone for preventing recurrence. We investigated the extent of cardiovascular risk factor management in males and females with and without familial hypercholesterolemia (FH) 5 years after ACS. METHODS: We studied patients hospitalized for ACS between 2009 and 2017 in a Swiss multicenter prospective cohort study. FH was defined based on clinical criteria from the Dutch Lipid Clinic Network and Simon Broome definitions. Five years post-ACS, we assessed low-density lipoprotein-cholesterol (LDL-c) levels, lipid-lowering therapy (LLT), and other cardiovascular risk factors, comparing males to females with and without FH using generalized estimating equations. RESULTS: A total of 3139 patients were included; mean age was 61.4 years (SD, 12.1), 620 (19.8%) were female, and 747 (23.5%) had possible FH. Compared with males at 5-years post-ACS, females were more likely to not use statins (odds ratio, 1.61 [95% CI, 1.28-2.03]) and less likely to have combination LLT (odds ratio, 0.72 [95% CI, 0.55-0.93]), without difference between patients with FH and without FH. Females in both FH and non-FH groups less frequently reached LDL-c values ≤1.8 mmol/L (odds ratio, 0.78 [95% CI, 0.78-0.93]). Overall, patients with FH were more frequently on high-dose statins compared with patients without FH (51.0% versus 42.9%; P=0.001) and presented more frequently with a combination of 2 or more LLT compared with patients without FH (33.8% versus 17.7%; P<0.001), but less frequently reached LDL-c targets of ≤1.8 mmol/L (33.5% versus 44.3%; P<0.001) or ≤2.6 mmol/L (70.2% versus 78.1%; P=0.001). CONCLUSIONS: Five years after ACS, females had less intensive LLT and were less likely to reach target LDL-c levels than males, regardless of FH status. Males and females with FH had less optimal control of LDL-c despite more frequently taking high-dose statins or combination LLT compared with patients without FH. Long-term management of patients with ACS and FH, especially females, warrants optimization.

[Pharmacological and clinical profile of inclisiran sodium, a long-acting LDL cholesterol lowering siRNA, LEQVIO for s.c. injection syringe 300†|mg].

Inclisiran sodium (Brand name: LEQVIO® for s.c. injection syringe 300 |mg, hereinafter referred to as inclisiran), a small interfering ribonucleic acid (siRNA) product that targets the mRNA that encodes the proprotein convertase subtilisin/kexin type 9 (PCSK9) protein was approved on September 25, 2023 for the indication of "Familial hypercholesterolemia, hypercholesterolemia" in Japan. Inclisiran is conjugated on the sense strand with triantennary N-acetylgalactosamine to facilitate uptake by hepatocytes. In vitro and in vivo pharmacology studies demonstrated the lowering effects of PCSK9 and LDL-C in hepatocytes and cynomolgus monkeys. It was considered unlikely to cause clinically significant risks due to toxicities arising from complementary binding to non-target RNA sequences (hybridization-dependent off-target effects). Clinical trials conducted globally including Japan in patients with familial hypercholesterolemia and hypercholesterolemia who did not reach the LDL-C target showed that inclisiran sodium 300 |mg dosed at Day 1, Day 90 and then every 6 months demonstrated significant LDL-C reduction and the efficacy sustained long. The majority of patients achieved the guideline recommended LDL-C targets. Inclisiran sodium 300 |mg was well tolerated and there were no specific safety concerns. Therefore, inclisiran is expected to be a new therapeutic option for the patients with familial hypercholesterolemia and hypercholesterolemia.

Hypercholesterolaemia treated with inclisiran.

In this case report, a 31-year-old woman with heterozygous familial hypercholesterolaemia (FH) underwent treatment with statins and PCSK9 inhibitor but had to discontinue due to elevated creatine kinase levels and neurological and muscular side effects. In 2021, the patient received inclisiran therapy, the first known instance of its application in Denmark. No side effects were reported, and LDL cholesterol levels were significantly reduced. This case report highlights the potential of inclisiran as an effective and well-tolerated treatment for individuals with heterozygous FH.

Alirocumab: Pediatric First Approval.

Alirocumab (Praluent®), a proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitor that has been co-developed by Regeneron Pharmaceuticals, Inc. and Sanofi (formerly sanofi-aventis), is approved globally for use in adults with established cardiovascular disease, primary hyperlipidemia [including heterozygous familial hypercholesterolemia (HeFH) or homozygous familial hypercholesterolemia (HoFH)]. In November 2023, based on clinical data in patients aged 8-17 years, alirocumab received its first pediatric approval in the EU as an adjunct to diet alone, or in combination with a statin and/or other low-density lipoprotein cholesterol (LDL-C)-lowering therapies, in pediatric patients aged ≥ 8 years with HeFH. Alirocumab was approved a few months later in the US for use as an adjunct to diet and other LDL-C-lowering therapies in pediatric patients aged ≥ 8 years with HeFH to reduce LDL-C. This article summarizes the milestones in the development of alirocumab leading to this first pediatric approval for HeFH.

Familial hypercholesterolemia care by Dutch pediatricians-mind the gaps.

PURPOSE: Familial hypercholesterolemia (FH) leads to elevated low-density lipoprotein cholesterol levels, which increases the risk of premature atherosclerotic cardiovascular disease (ASCVD). Since the first functional and morphologic changes of the arterial wall occur in childhood, treatment should start early in childhood to mitigate the elevated risk of ASCVD. Pediatricians play an important role in the detection and care of children with FH. In this study, we aim to explore potential gaps in FH care amongst Dutch pediatricians, in order to enhance their knowledge and awareness of detecting and treating children with FH. METHODS: An anonymous online survey, deployed using Google Forms, including 26 closed and semi-closed questions on FH care in children was distributed by the Dutch Association of Pediatrics via a newsletter to which the majority of the practicing Dutch pediatricians subscribe. In addition, we requested that the pediatric departments of all Dutch hospitals in the Netherlands distribute this survey personally among their employed pediatricians. Respondents were instructed to answer the questions without any help or use of online resources. RESULTS: Between September 1st, 2023 and November 1st, 2023, 158 (an estimated 11% response rate) Dutch pediatricians completed the survey. They reported a median (IQR) of 15.0 (6.0-22.0) years of experience as a pediatrician, and 34 (21.5%) were working in academic hospitals. The majority (76.6%) of pediatricians correctly identified a typical FH lipid profile but 68 (43.0%) underestimated the true prevalence of FH (1:300). Underestimation and unawareness of the increased risk of FH patients for ASCVD were reported by 37.3% and 25.9% of pediatricians, respectively. Although 70.9% of the pediatricians correctly defined FH, only 67 (42.4%) selected statins and ezetimibe to treat severe hypercholesterolemia. CONCLUSIONS: The results of this study suggest significant gaps in knowledge and awareness of FH in children among Dutch pediatricians. FH care in children needs improvement through educational and training initiatives to mitigate the life-long risk of ASCVD from early life. WHAT IS KNOWN: • Familial hypercholesterolemia (FH) leads to elevated LDL-cholesterol levels, which increases the risk of premature atherosclerotic cardiovascular disease (ASCVD). • The process of atherosclerosis starts in childhood • Pediatricians play an important role in the detection and treatment of children with FH. WHAT IS NEW: • Our results highlight significant gaps in care for children with FH amongst pediatricians and this may lead to suboptimal detection and treatment. • FH care in children needs improvement by educational initiatives to ultimately prevent ASCVD in adulthood.

Evinacumab: Mechanism of action, clinical, and translational science.

Homozygous familial hypercholesterolemia (HoFH) is a rare and serious genetic condition characterized by premature cardiovascular disease due to severely elevated low-density lipoprotein cholesterol (LDL-C). HoFH primarily results from loss-of-function (LOF) mutations in the LDL receptor (LDLR), reducing LDL-C clearance such that patients experience severe hypercholesterolemia, exacerbating the risk of developing cardiovascular events. Treatment options such as statins, lomitapide, ezetimibe, proprotein convertase subtilisin/kexin type 9 inhibitors, and apheresis help lower LDL-C; however, many patients with HoFH still fail to reach their target LDL-C levels and many of these lipid-lowering therapies are not indicated for pediatric use. Angiopoietin-like protein 3 (ANGPTL3) has been identified as a target to treat elevated LDL-C by acting as a natural inhibitor of lipoprotein lipase (LPL) and endothelial lipase (EL), enzymes involved in the hydrolysis of the triglyceride and phospholipid content of very low-density lipoproteins. Persons heterozygous for LOF mutations in ANGPTL3 were reported to have lower LDL-C than non-carriers and lower risk of coronary artery disease. Evinacumab is a first-in-class human monoclonal antibody that specifically binds to ANGPTL3 to prevent its inhibition of LPL and EL. In clinical trials, a 15 mg/kg intravenous dose every 4 weeks has shown a mean percent change from baseline in LDL-C of ~50% in adult, adolescent, and pediatric patients with HoFH. This mini review article describes the mechanism of action of evinacumab, evinacumab population PK and PD modeling, and clinical development history of evinacumab for the treatment of HoFH.

Obicetrapib on top of maximally tolerated lipid-modifying therapies in participants with or at high risk for atherosclerotic cardiovascular disease: rationale and designs of BROADWAY and BROOKLYN.

BACKGROUND: Obicetrapib, a novel, selective cholesteryl ester transfer protein (CETP) inhibitor, reduces low-density lipoprotein cholesterol (LDL-C), LDL particles, apolipoprotein (Apo) B, and lipoprotein(a) [Lp(a)] and increases high-density lipoprotein cholesterol (HDL-C) when added to statins with or without ezetimibe. By substantially reducing LDL-C, obicetrapib has the potential to lower atherogenic lipoproteins in patients with atherosclerotic cardiovascular disease (ASCVD) or heterozygous familial hypercholesterolemia (HeFH) whose LDL-C levels remain high despite treatment with available maximally tolerated lipid-modifying therapies, addressing an unmet medical need in a patient population at high risk for cardiovascular events. METHODS AND RESULTS: BROADWAY (NCT05142722) and BROOKLYN (NCT05425745) are ongoing placebo-controlled, double-blind, randomized Phase III trials designed to examine the efficacy, safety, and tolerability of obicetrapib as an adjunct to dietary intervention and maximally tolerated lipid-modifying therapies in participants with a history of ASCVD and/or underlying HeFH whose LDL-C is not adequately controlled. The primary efficacy endpoint was the percent change in LDL-C from baseline to day 84. Other endpoints included changes in Apo B, non-HDL-C, HDL-C, Apo A1, Lp(a), and triglycerides in addition to parameters evaluating safety, tolerability, and pharmacokinetics. BROADWAY also included an adjudicated assessment of major adverse cardiovascular events, measurements of glucose homeostasis, and an ambulatory blood pressure monitoring substudy. A total of 2,532 participants were randomized in BROADWAY and 354 in BROOKLYN to receive obicetrapib 10 mg or placebo (2:1) for 365 days with follow-up through 35 days after the last dose. Results from both trials are anticipated in 2024. CONCLUSION: These trials will provide safety and efficacy data to support the potential use of obicetrapib among patients with ASCVD or HeFH with elevated LDL-C for whom existing therapies are not sufficiently effective or well-tolerated.

Evinacumab and Cardiovascular Outcome in Patients With Homozygous Familial Hypercholesterolemia.

BACKGROUND: Patients with homozygous familial hypercholesterolemia (HoFH) remain at very high cardiovascular risk despite the best standard of care lipid-lowering treatment. The addition of evinacumab, an angiopoietin-like protein 3 monoclonal antibody, more than halves low-density lipoprotein cholesterol in short-term studies. This study evaluated whether the evinacumab response was durable in the long term and improved cardiovascular outcome. METHODS: The OLE ELIPSE HoFH (Open-Label Extension to Evinacumab Lipid Studies in Patients With HoFH) study included newly diagnosed patients and those completing the ELIPSE HoFH trial, on stable lipid-lowering therapy including lipoprotein apheresis but not lomitapide. All patients received evinacumab (15 mg/kg intravenously) every 4 weeks, with no change in concomitant lipid-lowering treatment during the first 6 months. The primary efficacy end points were the mean absolute and percentage changes in low-density lipoprotein cholesterol from baseline to 6 months. A key secondary end point was cardiovascular event-free survival, which was compared with a control HoFH cohort not treated with evinacumab or lomitapide and matched for age, sex, and lipoprotein apheresis, derived from French Registry of Familial hypercholesterolemia. RESULTS: Twelve patients, 5 women and 7 men (12-57 years), were enrolled in 3 centers in France. At 6 months, the mean low-density lipoprotein cholesterol reduction with evinacumab was 3.7 mmol/L or 56% (from 6.5 mmol/L at baseline to 2.8 mmol/L; P<0.0001) and was sustained over the median 3.5-year follow-up. No patients on evinacumab experienced cardiovascular events versus 13 events for 5/21 (24%) over 4 years in the control cohort (likelihood P=0.0267). CONCLUSIONS: Real-life, long-term evinacumab adjunctive to lipid-lowering therapy including lipoprotein apheresis led to sustained low-density lipoprotein cholesterol lowering and improved cardiovascular event-free survival of patients with HoFH.

A machine-learning algorithm using claims data to identify patients with homozygous familial hypercholesterolemia.

Homozygous familial hypercholesterolemia (HoFH) is an underdiagnosed and undertreated ultra-rare disease. We utilized claims data from the Komodo Healthcare Map database to develop a machine-learning model to identify potential HoFH patients. We tokenized patients enrolled in MyRARE (patient support program for those prescribed evinacumab-dgnb in the United States) and linked them with their Komodo claims. A true positive HoFH cohort (n = 331) was formed by including patients from MyRARE and patients with prescriptions for evinacumab-dgnb or lomitapide. The negative cohort (n = 1423) comprised patients with or at risk for cardiovascular disease. We divided the cohort into an 80% training and 20% testing set. Overall, 10,616 candidate features were investigated; 87 were selected due to clinical relevance and importance on prediction performance. Different machine-learning algorithms were explored, with fast interpretable greedy-tree sums selected as the final machine-learning tool. This selection was based on its satisfactory performance and its easily interpretable nature. The model identified four useful features and yielded precision (positive predicted value) of 0.98, recall (sensitivity) of 0.88, area under the receiver operating characteristic curve of 0.98, and accuracy of 0.97. The model performed well in identifying HoFH patients in the testing set, providing a useful tool to facilitate HoFH screening and diagnosis via healthcare claims data.

Predicted deleterious variants in ABCA1, LPL, LPA and KIF6 are associated with statin response and adverse events in patients with familial hypercholesterolemia and disturb protein structure and stability.

OBJECTIVES: This study explored the association of deleterious variants in pharmacodynamics (PD) genes with statin response and adverse effects in patients with familial hypercholesterolemia (FH) and analyzed their potential effects on protein structure and stability. METHODS: Clinical and laboratory data were obtained from 144 adult FH patients treated with statins. A panel of 32 PD genes was analyzed by exon-targeted gene sequencing. Deleterious variants were identified using prediction algorithms and their structural effects were analyzed by molecular modeling studies. RESULTS: A total of 102 variants were predicted as deleterious (83 missense, 8 stop-gain, 4 frameshift, 1 indel, 6 splicing). The variants ABCA1 rs769705621 (indel), LPA rs41267807 (p.Tyr2023Cys) and KIF6 rs20455 (p.Trp719Arg) were associated with reduced low-density lipoprotein cholesterol (LDLc) response to statins, and the LPL rs1801177 (p.Asp36Asn) with increased LDLc response (P < 0.05). LPA rs3124784 (p.Arg2016Cys) was predicted to increase statin response (P = 0.022), and ABCA1 rs769705621 to increase the risk of statin-related adverse events (SRAE) (P = 0.027). LPA p.Arg2016Cys and LPL p.Asn36Asp maintained interactions with solvent, LPA p.Tyr2023Cys reduced intramolecular interaction with Gln1987, and KIF6 p.Trp719Arg did not affect intramolecular interactions. DDMut analysis showed that LPA p.Arg2016Cys and p.Tyr2023Cys and LPL p.Asp36Asn caused energetically favorable changes, and KIF6 p.Trp719Arg resulted in unfavorable energetic changes, affecting protein stability. CONCLUSION: Deleterious variants in ABCA1, LPA, LPL and KIF6 are associated with variability in LDLc response to statins, and ABCA1 rs769705621 is associated with SRAE risk in FH patients. Molecular modeling studies suggest that LPA p.Tyr2023Cys and KIF6 p.Trp719Arg disturb protein conformational structure and stability.

Improved lipid-lowering treatment and reduction in cardiovascular disease burden in homozygous familial hypercholesterolemia: The SAFEHEART follow-up study.

AIM: We aimed to describe clinical and genetic characteristics, lipid-lowering treatment and atherosclerotic cardiovascular disease (ASCVD) outcomes over a long-term follow-up in homozygous familial hypercholesterolemia (HoFH). METHODS: SAFEHEART (Spanish Familial Hypercholesterolaemia Cohort Study) is a long-term study in molecularly diagnosed FH. Data analyzed in HoFH were prospectively obtained from 2004 until 2022. ASCVD events, lipid profile and lipid-lowering treatment were determined. RESULTS: Thirty-nine HoFH patients were analyzed. The mean age was 42 ± 20 years and nineteen (49%) were women. Median follow-up was 11 years (IQR 6,18). Median age at genetic diagnosis was 24 years (IQR 8,42). At enrolment, 33% had ASCVD and 18% had aortic valve disease. Patients with new ASCVD events and aortic valve disease at follow-up were six (15%), and one (3%), respectively. Median untreated LDL-C levels were 555 mg/dL (IQ 413,800), and median LDL-C levels at last follow-up was 122 mg/dL (IQR 91,172). Most patients (92%) were on high intensity statins and ezetimibe, 28% with PCSK9i, 26% with lomitapide, and 23% with lipoprotein-apheresis. Fourteen patients (36%) attained an LDL-C level below 100 mg/dL, and 10% attained an LDL-C below 70 mg/dL in secondary prevention. Patients with null/null variants were youngers, had higher untreated LDL-C and had the first ASCVD event earlier. Free-event survival is longer in patients with defective variant compared with those patients with at least one null variant (p=0.02). CONCLUSIONS: HoFH is a severe life threating disease with a high genetic and phenotypic variability. The improvement in lipid-lowering treatment and LDL-C levels have contributed to reduce ASCVD events.