Comparison of family history of sudden cardiac death in nonischemic and ischemic heart disease.
BACKGROUND
Recent studies have identified the presence of familial clustering of ischemic sudden cardiac death (SCD) as a clinical expression of coronary artery disease. The purpose of this study was to determine whether nonischemic SCD has a similar familial background, which would be evidence of a genetic predisposition.


RESULTS
The retrospective case-control study included (1) consecutive victims of nonischemic SCD (n=223), (2) consecutive victims of ischemic SCD (n=596), whose deaths and diagnosis were verified at medicolegal autopsy, and (3) control subjects without heart disease (n=475). In each study group, the family history of SCD among the first-degree relatives was determined and verified from death certificates. The prevalence of SCD in ≥1 first-degree relative was significantly higher in victims of ischemic (34.2%) than nonischemic SCD (13.4%; P<0.001) or controls (17.6%; P<0.001). The history of SCD in first-degree relatives did not differ from controls in nonischemic SCD victims (P=0.155). In a subgroup analysis of victims of ischemic SCD, the prevalence of family history of SCD in first-degree relatives did not differ between those with or without a prior infarct scar at autopsy (33.1% versus 29.9%, respectively; P=0.222).


CONCLUSIONS
Ischemic SCD has a strong familial background both in cases with and without a prior myocardial infarction. The family history of SCD is not significantly increased in victims of nonischemic SCD, suggesting a larger role of sporadic occurrence than inherited traits as the cause of nonischemic SCD.
Department of Internal Medicine, Institute of Clinical Medicine, University of Oulu, Oulu, Finland. eeva.hookana@oulu.fi
Eeva
E
Hookana
M Juhani
MJ
Junttila
Kari S
KS
Kaikkonen
Olavi
O
Ukkola
Y Antero
YA
Kesäniemi
Marja-Leena
ML
Kortelainen
Heikki V
HV
Huikuri
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001344:Autopsy; D016009:Chi-Square Distribution; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D005387:Finland / Q000453:epidemiology; D020022:Genetic Predisposition to Disease; D006331:Heart Diseases / Q000175:diagnosis / Q000235:genetics / Q000401:mortality*; D040941:Heredity; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D009203:Myocardial Infarction / Q000235:genetics / Q000401:mortality; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000235:genetics / Q000401:mortality*; D016017:Odds Ratio; D010375:Pedigree; D010641:Phenotype; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors