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Home / Equine Research Bank / Equine Vet J / Heritability of sudden cardiac death in Thoroughbred racehor...
Equine veterinary journal2024; doi: 10.1111/evj.14130

Heritability of sudden cardiac death in Thoroughbred racehorses.

Abstract: Sudden cardiac death (SCD) is an important cause of exercise-associated fatalities in Thoroughbred racehorses. Equine deaths share similarities with fatalities in human athletes that result from inherited cardiac disease. Whilst genetic causes have been postulated in horses, these have not been confirmed and heritability of SCD has not previously been estimated in Thoroughbred racehorses. Objective: To determine the heritability of SCD in a sample population of Thoroughbred racehorses. Methods: Retrospective case-control study. Methods: Steward and post-mortem reports of Thoroughbred racehorses in Australia between 2007 and 2020 were reviewed to identify horses with SCD. Control horses were randomly selected from races in which SCD occurred or from races on the date of the case fatality. A five-generation integrated pedigree chart was collected for each horse. Estimates of heritability were obtained using an animal model in the ASReml-R program with variance components estimated assuming SCD was normally distributed, and on the logit transformed scale. Inbreeding coefficients were calculated and the risk of producing SCD-affected progeny was calculated for stallions that sired ≥5 individuals in the case-control population. Results: Ninety-three horses with SCD and 465 control horses were identified. Heritability on the underlying scale was 0.15 ± 0.09 (logit animal) and 0.24 ± 0.12 (normal animal). Inbreeding coefficients were not significantly different between groups. Of the 16 first generation sires that appeared ≥5 times in the case-control data set, two sires more frequently produced affected progeny (OR 7.95-10.41). Conclusions: Challenges in definitively confirming SCD may lead to misclassification of some cases. Some control horses may have not been exposed to environmental influences of SCD. Case numbers are low and the studied population may not represent the entire Thoroughbred genetic pool. Conclusions: The heritability of SCD in this population was relatively low. However, individual stallions appear more likely to produce affected progeny. Further studies are required to understand the genetic and environmental influences that contribute to disease expression.
© 2024 The Author(s). Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.
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Publication Date: 2024-07-10 PubMed ID: 38984817DOI: 10.1111/evj.14130Google Scholar: Lookup
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Summary

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This research investigates the heritability of sudden cardiac death (SCD) in Thoroughbred racehorses, indicating that, while the heritability is relatively low, individual stallions can be more likely to produce affected offspring.

Objective of the Research

  • The primary goal of this study was to determine the heritability of Sudden Cardiac Death (SCD) in a selected population of Thoroughbred racehorses.

Methods Employed

  • The researchers carried out a retrospective case-control study. They reviewed steward and post-mortem reports of Thoroughbred racehorses in Australia from between 2007 and 2020 to identify horses that suffered from SCD.
  • Control horses were chosen randomly from races in which SCD occurred or from races on the date of the case fatality.
  • They compiled five-generation integrated pedigree charts for all horses in the study. Using an animal model in the ASReml-R program, they estimated heritability, under the assumption that SCD was normally distributed.
  • Inbreeding coefficients were computed, and the risk of producing SCD-affected offspring was calculated for stallions that sired five or more individuals in the case-control population.

Results Gained

  • The researchers identified 93 horses with SCD and 465 control horses. The heritability on the underlying scale was found to be relatively low, at 0.15 ± 0.09 (logit animal) and 0.24 ± 0.12 (normal animal).

  • There was no significant difference in the inbreeding coefficients between groups.
  • Out of the 16 first-generation stallions that appeared five or more times in the case-control data set, two stallions were identified as producing affected offspring more frequently.

Conclusions Reached

  • Challenges in positively identifying SCD might lead to misclassification of some cases. Additionally, some of the control horses may not have been exposed to environmental influences of SCD.
  • The researchers note that the case numbers are low, and the population studied may not represent the entire Thoroughbred genetic pool.
  • Despite these limitations, the study concludes that while the heritability of SCD in this population was low, individual stallions appear more likely to produce affected progeny. They recommend further studies to understand the genetic and environmental influences that contribute to disease expression.

Cite This Article

APA
Kapusniak A, Nath L, Hebart M, Franklin S. (2024). Heritability of sudden cardiac death in Thoroughbred racehorses. Equine Vet J. https://doi.org/10.1111/evj.14130

Publication

Equine veterinary journal
ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English

Researcher Affiliations

Kapusniak, Amie
  • School of Animal & Veterinary Sciences, University of Adelaide, Adelaide, South Australia, Australia.
Nath, Laura
  • School of Animal & Veterinary Sciences, University of Adelaide, Adelaide, South Australia, Australia.
Hebart, Michelle
  • School of Animal & Veterinary Sciences, University of Adelaide, Adelaide, South Australia, Australia.
Franklin, Samantha
  • School of Animal & Veterinary Sciences, University of Adelaide, Adelaide, South Australia, Australia.

References

This article includes 58 references
  1. Lyle CH, Blissitt KJ, Kennedy RN, McGorum BC, Newton JR, Parkin TDH. Risk factors for race‐associated sudden death in Thoroughbred racehorses in the UK (2000–2007). Equine Vet J 2012;44(4):459–465.
    doi: 10.1111/j.2042-3306.2011.00496.xgoogle scholar: lookup
  2. Physick‐Sheard PW, Slack J. Irregular hearts and performance horses. Equine Vet J 2020;52(6):782–786.
    doi: 10.1111/evj.13316google scholar: lookup
  3. Boden LA, Charles JA, Slocombe RF, Sandy JR, Finnin PJ, Morton JM. Sudden death in racing Thoroughbreds in Victoria, Australia. Equine Vet J 2005;37(3):269–271.
  4. Gelberg HB, Zachary JF, Everitt JI, Jensen RC, Smetzer DL. Sudden death in training and racing Thoroughbred horses. J Am Vet Med Assoc 1985;187(12):1354–1356.
  5. Nath L, Stent A, Elliott A, La Gerche A, Franklin S. Risk factors for exercise‐associated sudden cardiac death in Thoroughbred racehorses. Animals 2022;12(10):1297.
    doi: 10.3390/ani12101297google scholar: lookup
  6. Navas de Solis C, Althaus F, Basieux N, Burger D. Sudden death in sport and riding horses during and immediately after exercise: a case series. Equine Vet J 2018;50(5):644–648.
    doi: 10.1111/evj.12803google scholar: lookup
  7. Lyle CH, Uzal FA, McGorum BC, Aida H, Blissitt KJ, Case JT. Sudden death in racing Thoroughbred horses: an international multicentre study of post mortem findings. Equine Vet J 2011;43(3):324–331.
    doi: 10.1111/j.2042-3306.2010.00164.xgoogle scholar: lookup
  8. Platt H. Sudden and unexpected deaths in horses: a review of 69 cases. Br Vet J 1982;138(5):417–429.
  9. Schoen FJ. The heart in Robbins pathological basis of disease. In: Cotran RS, Kumar V, Collins T, editors. Robbins Pathologic Basis of Disease. Volume 6. Philadelphia, PA: WB Saunders Co; 1999. p. 570–572.
  10. Kiryu K, Machida N, Kashida Y, Yoshihara T, Amada A, Yamamoto T. Pathologic and electrocardiographic findings in sudden cardiac death in racehorses. J Vet Med Sci 1999;61(8):921–928.
    doi: 10.1292/jvms.61.921google scholar: lookup
  11. Longo UG, Risi Ambrogioni L, Ciuffreda M, Maffulli N, Denaro V. Sudden cardiac death in young athletes with long QT syndrome: the role of genetic testing and cardiovascular screening. Br Med Bull 2018;127(1):43–53.
    doi: 10.1093/bmb/ldy017google scholar: lookup
  12. Corrado D, Zorzi A. Natural history of arrhythmogenic cardiomyopathy: redefining the age range of clinical presentation. Heart Rhythm 2017;14(6):892–893.
    doi: 10.1016/j.hrthm.2017.02.031google scholar: lookup
  13. Molesan A, Wang M, Sun Q, Pierce V, Desideri R, Palmer S. Cardiac pathology and genomics of sudden death in racehorses from New York and Maryland racetracks. Vet Pathol 2019;56(4):576–585.
    doi: 10.1177/0300985819829529google scholar: lookup
  14. Trachsel DS, Calloe K, Mykkänen AK, Raistakka P, Anttila M, Fredholm M. Exercise‐associated sudden death in Finnish Standardbred and coldblooded trotters—a case series with pedigree analysis. J Equine Vet 2021;104:103694.
    doi: 10.1016/j.jevs.2021.103694google scholar: lookup
  15. https://racing.racingnsw.com.au/FreeFields/Race_Diary_Stewards.aspx
  16. https://www.theracessa.com.au/race-info/stewards-reports
  17. https://www.racingvictoria.com.au/integrity/stewards/stewards-reports
  18. https://racingaustralia.horse/
  19. http://www.studbook.org.au/
  20. Butler DG, Cullis BR, Gilmour AR, Gogel BJ. ASReml‐R reference manual. Department of Primary Industries and Fisheries: Brisbane; 2009.
  21. Physick‐Sheard P, Kraus M, Basrur P, McGurrin K, Kenney D, Schenkel F. Breed predisposition and heritability of atrial fibrillation in the Standardbred horse: a retrospective case–control study. J Vet Cardiol 2014;16(3):173–184.
    doi: 10.1016/j.jvc.2014.03.006google scholar: lookup
  22. Pedler C, Nath L, Agne GF, Hebart M, Franklin S. Heritability estimates of atrial fibrillation in Thoroughbred racehorses in Hong Kong and Australia. J Vet Cardiol 2021;36:115–122.
    doi: 10.1016/j.jvc.2021.05.008google scholar: lookup
  23. Racing Australia. Horse Racing Results (No Date) Racing Australia Fact Book. Available from: https://www.racingaustralia.horse/Aboutus/FactBook.aspx
  24. Usman MG, Rafii MY, Ismail MR, Malek MA, Abdul LM. Heritability and genetic advance among chili pepper genotypes for heat tolerance and morphophysiological characteristics. Sci World J 2014;2014:308042.
    doi: 10.1155/2014/308042google scholar: lookup
  25. Safari E, Fogarty NM, Gilmour AR. A review of genetic parameter estimates for wool, growth, meat and reproduction traits in sheep. Livest Prod Sci 2005;92(3):271–289.
    doi: 10.1016/j.livprodsci.2004.09.003google scholar: lookup
  26. Lopez‐Villalobos N, Garrick DJ. Genetic parameter estimates for lamb survival in Romney sheep. N Z Soc Anim Prod 1999;59:121–124.
  27. Oki H, Miyake T, Kasashima Y, Sasaki Y. Estimation of heritability for superficial digital flexor tendon injury by Gibbs sampling in the Thoroughbred racehorse. J Anim Breed Genet 2008;125(6):413–416.
    doi: 10.1111/j.1439-0388.2008.00758.xgoogle scholar: lookup
  28. Welsh CE, Lewis TW, Blott SC, Mellor DJ, Lam KH, Stewart BD. Preliminary genetic analyses of important musculoskeletal conditions of Thoroughbred racehorses in Hong Kong. Vet J 2013;198(3):611–615.
    doi: 10.1016/j.tvjl.2013.05.002google scholar: lookup
  29. Russell J, Matika O, Russell T, Reardon RJM. Heritability and prevalence of selected osteochondrosis lesions in yearling Thoroughbred horses. Equine Vet J 2017;49(3):282–287.
    doi: 10.1111/evj.12613google scholar: lookup
  30. Weideman H, Schoeman SJ, Jordaan GF. The inheritance of liability to epistaxis in the southern African thoroughbred. J South Afr Vet Assoc 2004;75(4):158–162.
  31. Velie BD, Raadsma HW, Wade CM, Knight PK, Hamilton NA. Heritability of epistaxis in the Australian Thoroughbred racehorse population. Vet J 2014;202(2):274–278.
    doi: 10.1016/j.tvjl.2014.06.010google scholar: lookup
  32. Ibi T, Miyake T, Hobo S, Oki H, Ishida N, Sasaki Y. Estimation of heritability of laryngeal hemiplegia in the thoroughbred horse by Gibbs sampling. J Equine Sci 2003;14(3):81–86.
    doi: 10.1294/jes.14.81google scholar: lookup
  33. Mahon GAT, Cunningham EP. Inbreeding and the inheritance of fertility in the Thoroughbred mare. Livest Prod Sci 1982;9(6):743–754.
    doi: 10.1016/0301-6226(82)90021-5google scholar: lookup
  34. Cunningham EP, Dooley JJ, Splan RK, Bradley DG. Microsatellite diversity, pedigree relatedness and the contributions of founder lineages to Thoroughbred horses. Anim Genet 2001;32(6):360–364.
    doi: 10.1046/j.1365-2052.2001.00785.xgoogle scholar: lookup
  35. Binns MM, Boehler DA, Bailey E, Lear TL, Cardwell JM, Lambert DH. Inbreeding in the Thoroughbred horse. Anim Genet 2012;43(3):340–342.
    doi: 10.1111/j.1365-2052.2011.02259.xgoogle scholar: lookup
  36. Andersson L, Georges M. Domestic‐animal genomics: deciphering the genetics of complex traits. Nat Rev Genet 2004;5(3):202–212.
  37. Brosnahan MM, Brooks SA, Antczak DF. Equine clinical genomics: a clinician's primer. Equine Vet J 2010;42(7):658–670.
    doi: 10.1111/j.2042-3306.2010.00166.xgoogle scholar: lookup
  38. Flash ML, Shrestha K, Stevenson MA, Gilkerson JR. National participation levels in the 2017–2018 Australian thoroughbred racing season. Aust Vet J 2023;101(7):265–274.
  39. Wasfy MM, Hutter AM, Weiner RB. Sudden cardiac death in athletes. Methodist DeBakey Cardiovasc J 2016;12(2):76–80.
    doi: 10.14797/mdcj-12-2-76google scholar: lookup
  40. Jazayeri MA, Emert MP. Sudden cardiac death: who is at risk?. Med Clin 2019;103(5):913–930.
    doi: 10.1016/j.mcna.2019.04.006google scholar: lookup
  41. Maron BJ, Doerer JJ, Haas TS, Tierney DM, Mueller FO. Sudden deaths in young competitive athletes: analysis of 1866 deaths in the United States, 1980–2006. Circulation 2009;119(8):1085–1092.
    doi: 10.1161/circulationaha.108.804617google scholar: lookup
  42. Winkel BG, Risgaard B, Bjune T, Jabbari R, Lynge TH, Glinge C. Gender differences in sudden cardiac death in the young‐a nationwide study. BMC Cardiovasc Disord 2017;17(1):1–8.
  43. Finocchiaro G, Papadakis M, Robertus JL, Dhutia H, Steriotis AK, Tome M. Etiology of sudden death in sports: insights from a United Kingdom regional registry. J Am Coll Cardiol 2016;67(18):2108–2115.
  44. Semsarian C, Sweeting J, Ackerman MJ. Sudden cardiac death in athletes. BMJ 2015;350:350.
    doi: 10.1136/bmj.h1218google scholar: lookup
  45. D'Silva A, Papadakis M. Sudden cardiac death in athletes. Eur Cardiol Rev 2015;10(1):48–53.
    doi: 10.15420/ecr.2015.10.01.48google scholar: lookup
  46. Emery MS, Kovacs RJ. Sudden cardiac death in athletes. JACC Heart Fail 2018;6(1):30–40.
    doi: 10.1016/j.jchf.2017.07.014google scholar: lookup
  47. Ripoll‐Vera T, Luengo CP, Alcázar JCB, Ruiz ABG, Del Valle NS, Martín BB. Sudden cardiac death in persons aged 50 years or younger: diagnostic yield of a regional molecular autopsy program using massive sequencing. Rev Esp Cardiol 2021;74(5):402–413.
    doi: 10.1016/j.rec.2020.03.030google scholar: lookup
  48. DeLay J. Postmortem findings in Ontario racehorses, 2003–2015. J Vet Diagn Invest 2017;29(4):457–464.
    doi: 10.1177/1040638717700690google scholar: lookup
  49. Torkamani A, Muse ED, Spencer EG, Rueda M, Wagner GN, Lucas JR. Molecular autopsy for sudden unexpected death. JAMA 2016;316(14):1492–1494.
  50. Pedersen PJ, Thomsen KB, Olander ER, Hauser F, Tejada MDLA, Poulsen KL. Molecular cloning and functional expression of the equine K+ channel KV11. 1 (ether a go‐go‐related/KCNH2 gene) and the regulatory subunit KCNE2 from equine myocardium. PLoS One 2015;10(9):e0138320.
    doi: 10.1371/journal.pone.0138320google scholar: lookup
  51. Pedersen PJ, Thomsen KB, Flak JB, Tejada MA, Hauser F, Trachsel D. Molecular cloning and functional expression of the K+ channel KV7. 1 and the regulatory subunit KCNE1 from equine myocardium. Res Vet Sci 2017;113:79–86.
    doi: 10.1016/j.rvsc.2017.09.010google scholar: lookup
  52. Creighton W, Virmani R, Kutys R, Burke A. Identification of novel missense mutations of cardiac ryanodine receptor gene in exercise‐induced sudden death at autopsy. J Mol Diagn 2006;8(1):62–67.
    doi: 10.2353/jmoldx.2006.050081google scholar: lookup
  53. Miotto MC, Weninger G, Dridi H, Yuan Q, Liu Y, Wronska A. Structural analyses of human ryanodine receptor type 2 channels reveal the mechanisms for sudden cardiac death and treatment. Sci Adv 2022;8(29):eabo1272.
    doi: 10.1126/sciadv.abo1272google scholar: lookup
  54. Lehnart SE, Mongillo M, Bellinger A, Lindegger N, Chen BX, Hsueh W. Leaky Ca2+ release channel/ryanodine receptor 2 causes seizures and sudden cardiac death in mice. J Clin Invest 2008;118(6):2230–2245.
  55. Van Oort RJ, McCauley MD, Dixit SS, Pereira L, Yang Y, Respress JL. Ryanodine receptor phosphorylation by calcium/calmodulin‐dependent protein kinase II promotes life‐threatening ventricular arrhythmias in mice with heart failure. Circulation 2010;122(25):2669–2679.
  56. Basaki M, Tabandeh MR, Aminlari M, Asasi K, Mohsenifard E, Abdi‐Hachesoo B. Sequence and expression analysis of cardiac ryanodine receptor 2 in broilers that died from sudden death syndrome. Avian Pathol 2019;48(5):444–453.
    doi: 10.1080/03079457.2019.1618439google scholar: lookup
  57. Shoemaker S, Wang Y, Sellon D, Gold J, Fisher A, Bagshaw J. Prevalence and severity of exercise‐induced pulmonary hemorrhage in 2‐year‐old Thoroughbred racehorses and its relationship to performance. J Vet Intern Med 2024;38:1167–1176.
    doi: 10.1111/jvim.17003google scholar: lookup
  58. Rocchigiani G, Verin R, Uzal FA, Singer ER, Pregel P, Ressel L. Pulmonary bleeding in racehorses: a gross, histologic, and ultrastructural comparison of exercise‐induced pulmonary hemorrhage and exercise‐associated fatal pulmonary hemorrhage. Vet Pathol 2022;59(6):973–982.
    doi: 10.1177/03009858221117859google scholar: lookup

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