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Brown L, Ruel I, Baass A, Bergeron J, Brunham LR, Cermakova L, Couture P, Gaudet D, Francis GA, Hegele RA, Iatan I, Mancini GJ, McCrindle BW, Ransom T, Sherman MH, McPherson R, Genest J. Homozygous Familial Hypercholesterolemia in Canada: An Observational Study. JACC. ADVANCES 2023; 2:100309. [PMID: 38939573 PMCID: PMC11198203 DOI: 10.1016/j.jacadv.2023.100309] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/17/2023] [Accepted: 02/28/2023] [Indexed: 06/29/2024]
Abstract
Background Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disease characterized by very high levels of low-density lipoprotein cholesterol (LDL-C). Untreated patients present with extensive xanthomas and premature atherosclerosis. Lipid-lowering therapy is highly efficacious and has dramatically increased life expectancy of patients with HoFH. Objectives The aim of the study was to obtain a comprehensive registry of HoFH in Canada, known to have several founder effect regions, and describe the clinical characteristics and cardiovascular outcomes of this population over time. Methods Clinical and genetic data on patients with HoFH were collected via a standardized questionnaire sent to academic sites participating in the Familial Hypercholesterolemia Canada network. Results A total of 48 patients with HoFH were enrolled. The median age at diagnosis was 12 years (interquartile range [IQR]: 5-24) and untreated LDL-C levels were 15.0 mmol/L (IQR: 10.5-18.6 mmol/L; 580 mg/dL IQR: 404-717 mg/dL). At last follow-up visit, median age was 40 years (IQR: 26-54 years). Treated LDL-C levels were 6.75 mmol/L (IQR: 4.73-9.51 mmol/L; 261 mg/dL IQR: 183-368 mg/dL) with 95.5% of patients on statins, 88.6% on ezetimibe, 34.1% on proprotein convertase subtilisin/kexin type 9 inhibitors, 27.3% on lomitapide, 13.6% on evinacumab, and 56.8% were treated with low-density lipoprotein apheresis or plasmapheresis. Deaths were reported in 7 (14.5%) and major adverse cardiovascular events were observed in 14.6% of patients with the average onset at 30 years (IQR: 20-36 years). Aortic stenosis was reported in one-half the patients (47.9%) and 10 (20.8%) underwent aortic valve replacement. Conclusions This HoFH patient registry in Canada will provide important new health-related knowledge about the phenotypic manifestations and determinants of cardiovascular risk in this population, allowing for closer examination of quality of life and burden to the health care system.
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Affiliation(s)
- Leslie Brown
- Department of Medicine, Research Institute of the McGill University Health Centre, Montreal, Québec, Canada
| | - Isabelle Ruel
- Department of Medicine, Research Institute of the McGill University Health Centre, Montreal, Québec, Canada
| | - Alexis Baass
- Department of Medicine, Research Institute of the McGill University Health Centre, Montreal, Québec, Canada
| | - Jean Bergeron
- Endocrinology and Nephrology Unit, CHU de Québec - Université Laval Research Center, Québec City, Québec, Canada
| | - Liam R. Brunham
- Centre for Heart Lung Innovation, Providence Health Care Research Institute, Vancouver, British Columbia, Canada
- Departments of Medicine and Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lubomira Cermakova
- Centre for Heart Lung Innovation, Providence Health Care Research Institute, Vancouver, British Columbia, Canada
- Departments of Medicine and Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Patrick Couture
- Endocrinology and Nephrology Unit, CHU de Québec - Université Laval Research Center, Québec City, Québec, Canada
| | - Daniel Gaudet
- Lipidology Unit, Department of Medicine, Community Genomic Medicine Center, Université de Montréal and ECOGENE-21 Clinical and Translational Research Center, Chicoutimi, Québec, Canada
| | - Gordon A. Francis
- Centre for Heart Lung Innovation, Providence Health Care Research Institute, Vancouver, British Columbia, Canada
- Departments of Medicine and Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Robert A. Hegele
- Departments of Medicine and Biochemistry, Schulich School of Medicine and Robarts Research Institute, Western University, London, Ontario, Canada
| | - Iulia Iatan
- Centre for Heart Lung Innovation, Providence Health Care Research Institute, Vancouver, British Columbia, Canada
- Departments of Medicine and Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - G.B. John Mancini
- Centre for Cardiovascular Innovation, University of British Columbia, Vancouver, British Columbia, Canada
| | - Brian W. McCrindle
- Department of Pediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Thomas Ransom
- Queen Elizabeth II Health Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Mark H. Sherman
- Department of Endocrinology, McGill University Health Centre, Montreal, Québec, Canada
| | - Ruth McPherson
- Lipid Clinic & Atherogenomics Laboratory, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Jacques Genest
- Department of Medicine, Research Institute of the McGill University Health Centre, Montreal, Québec, Canada
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Abstract
PURPOSE OF REVIEW We reviewed current and future therapeutic options for patients with homozygous familial hypercholesterolemia (HoFH) and place this evidence in context of an adaptable treatment algorithm. RECENT FINDINGS Lowering LDL-C levels to normal in patients with HoFH is challenging, but a combination of multiple lipid-lowering therapies (LLT) is key. Patients with (near) absence of LDL receptor expression are most severely affected and frequently require regular lipoprotein apheresis on top of combined pharmacologic LLT. Therapies acting independently of the LDL receptor pathway, such as lomitapide and evinacumab, are considered game changers for many patients with HoFH, and may reduce the need for lipoprotein apheresis in future. Liver transplantation is to be considered a treatment option of last resort. Headway is being made in gene therapy strategies, either aiming to permanently replace or knock out key lipid-related genes, with first translational steps into humans being made. Cardiovascular disease risk management beyond LDL-C, such as residual Lp(a) or inflammatory risk, should be evaluated and addressed accordingly in HoFH. SUMMARY Hypercholesterolemia is notoriously difficult to control in most patients with HoFH, but multi-LLT, including newer drugs, allows reduction of LDL-C to levels unimaginable until a few years ago. Cost and availability of these new therapies are important future challenges to be addressed.
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Affiliation(s)
- Tycho R. Tromp
- Department of Vascular Medicine, Amsterdam UMC, Location AMC, Amsterdam, The Netherlands
| | - Marina Cuchel
- Department of Medicine, Division of Translational Medicine and Human Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Bélanger AM, Akioyamen L, Alothman L, Genest J. Evidence for improved survival with treatment of homozygous familial hypercholesterolemia. Curr Opin Lipidol 2020; 31:176-181. [PMID: 32520777 DOI: 10.1097/mol.0000000000000686] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE OF REVIEW Homozygous familial hypercholesterolemia (HoFH) is an orphan disease caused by biallelic mutations at the LDL receptor (LDLR) gene, with a prevalence estimated at 1 : 250 000 to 1 : 630 000. HoFH is characterized by extremely elevated plasma levels of LDL-C greater than 10 mmol/l (>387 mg/dl), tendinous and cutaneous xanthomas in youth and premature atherosclerotic cardiovascular disease (ASCVD). The expected prevalence varies from country to country depending on the presence of founder effects, genetic probability and life expectancy. Untreated, HoFH is a fatal condition before age 30. Plasma levels of LDL-C are the major cause of mortality and the therapeutic target. Statin therapy led to a remarkable improvement in survival but is of limited use in loss-of-function LDLR gene variants or 'null' mutations. Inhibitors of PCSK9 are a useful adjunct in patients with LDLR mutations with residual activity. Extracorporeal LDL filtration has improved survival since its introduction three decades ago. RECENT FINDINGS Novel therapies, not dependent on a functioning LDLR include lomitapide and mipomersen, which decrease hepatic apolipoprotein B secretion, and evinacumab, directed at the angiopoietin like-3 protein (ANGPLT-3). SUMMARY Over the past 3-4 decades, the survival of patients with HoFH has increased markedly. New therapeutic options offer new hope.
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Affiliation(s)
- Alexandre M Bélanger
- Research Institute of the McGill University Health Centre, Royal Victoria Hospital, Montreal, Quebec
| | - Leo Akioyamen
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Latifah Alothman
- Research Institute of the McGill University Health Centre, Royal Victoria Hospital, Montreal, Quebec
| | - Jacques Genest
- Research Institute of the McGill University Health Centre, Royal Victoria Hospital, Montreal, Quebec
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