Risk of death in the long QT syndrome when a sibling has died.
BACKGROUND
Sudden death of a sibling is thought to be associated with greater risk of death in long QT syndrome (LQTS). However, there is no evidence of such an association.


OBJECTIVE
This study sought to test the hypothesis that sudden death of a sibling is a risk factor for death or aborted cardiac arrest (ACA) in patients with LQTS.


METHODS
We examined all probands and first-degree and second-degree relatives in the International Long QT Registry from birth to age 40 years with QTc >/= 0.45 s. Covariates included sibling death, QTc, gender by age, syncope, and implantable cardioverter-defibrillator (ICD) and beta-blocker treatment. End points were (1) severe events (ACA, LQTS-related death) and (2) any cardiac event (syncope, ACA, or LQTS-related death).


RESULTS
Of 1915 subjects, 270 had a sibling who died. There were 213 severe events and 829 total cardiac events. More subjects with history of sibling death received beta-blocker therapy. Sibling death was not significantly associated with risk of ACA or LQTS-related death, but was associated with increased risk of syncope. QTc >/= 0.53 s (hazard ratio 2.5, P <.01), history of syncope (hazard ratio 6.1, P <.01), and gender were strongly associated with risk of ACA or LQTS-related death.


CONCLUSIONS
Sudden death of a sibling prompted more aggressive treatment but did not predict risk of death or ACA, whereas QTc >/= 0.53 s, gender, and syncope predicted this risk. All subjects should receive appropriate beta-blocker therapy. The decision to implant an ICD should be based on an individual's own risk characteristics (QTc, gender, and history of syncope).
Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, USA. ekaufman@metrohealth.org
Elizabeth S
ES
Kaufman
Scott
S
McNitt
Arthur J
AJ
Moss
Wojciech
W
Zareba
Jennifer L
JL
Robinson
W Jackson
WJ
Hall
Michael J
MJ
Ackerman
Jesaia
J
Benhorin
Emanuela T
ET
Locati
Carlo
C
Napolitano
Silvia G
SG
Priori
Peter J
PJ
Schwartz
Jeffrey A
JA
Towbin
G Michael
GM
Vincent
Li
L
Zhang
D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000328:Adult; D002648:Child; D002675:Child, Preschool; D016757:Death, Sudden, Cardiac / Q000209:etiology* / Q000517:prevention & control; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008133:Long QT Syndrome / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology; D008297:Male; D008487:Medical History Taking; D011446:Prospective Studies; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D035781:Siblings; D013575:Syncope; D016171:Torsades de Pointes / Q000209:etiology
D000319:Adrenergic beta-Antagonists