Who are the long-QT syndrome patients who receive an implantable cardioverter-defibrillator and what happens to them?: data from the European Long-QT Syndrome Implantable Cardioverter-Defibrillator (LQTS ICD) Registry.
BACKGROUND
A rapidly growing number of long-QT syndrome (LQTS) patients are being treated with an implantable cardioverter-defibrillator (ICD). ICDs may pose problems, especially in the young. We sought to determine the characteristics of the LQTS patients receiving an ICD, the indications, and the aftermath.


RESULTS
The study population included 233 patients. Beginning in 2002, data were collected prospectively. Female patients (77%) and LQT3 patients (22% of genotype positive) were overrepresented; mean QTc was 516±65 milliseconds; mean age at implantation was 30±17 years; and genotype was known in 59% of patients. Unexpectedly, 9% of patients were asymptomatic before implantation. Asymptomatic patients, almost absent among LQT1 and LQT2 patients, represented 45% of LQT3 patients. Patients with cardiac symptoms made up 91% of all study participants, but only 44% had cardiac arrest before ICD implantation. In addition, 41% of patients received an ICD without having first been on LQTS therapy. During follow-up, 4.6±3.2 years, at least 1 appropriate shock was received by 28% of patients, and adverse events occurred in 25%. Appropriate ICD therapies were predicted by age <20 years at implantation, a QTc >500 milliseconds, prior cardiac arrest, and cardiac events despite therapy; within 7 years, appropriate shocks occurred in no patients with none of these factors and in 70% of those with all factors.


CONCLUSIONS
Reflecting previous concepts, ICDs were implanted in some LQTS patients whose high risk now appears questionable. Refined criteria for implantation, reassessment of pros and cons, ICD reprogramming, and consideration for other existing therapeutic options are necessary.
Schwartz
Peter J
PJ
Department of Cardiology, Fondazione IRCCS Policlinico S. Matteo, V. le Golgi, 19-27100 Pavia, Italy. peter.schwartz@unipv.it
Spazzolini
Carla
C
Priori
Silvia G
SG
Crotti
Lia
L
Vicentini
Alessandro
A
Landolina
Maurizio
M
Gasparini
Maurizio
M
Wilde
Arthur A M
AA
Knops
Reinoud E
RE
Denjoy
Isabelle
I
Toivonen
Lauri
L
Mönnig
Gerold
G
Al-Fayyadh
Majid
M
Jordaens
Luc
L
Borggrefe
Martin
M
Holmgren
Christina
C
Brugada
Pedro
P
De Roy
Luc
L
Hohnloser
Stefan H
SH
Brink
Paul A
PA
D000293:Adolescent; D000328:Adult; D002648:Child; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D005060:Europe; D005260:Female; D005838:Genotype; D006801:Humans; D008133:Long QT Syndrome / Q000235:genetics / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012042:Registries; D016896:Treatment Outcome; D055815:Young Adult