Arrhythmias & electrophysiologyCohort study
Long QT syndrome: importance of reassessing arrhythmic risk after treatment initiation
- Cohort study
Authors' conclusion
Beta-blockers often shorten QTc, thus changing risk scores and ICD indications for primary prevention. Yearly risk reassessment with therapy optimization leads to fewer ICD implants (3%) without increasing life-threatening events.
Study context
- Population
- LQT1/2/3 and genotype-negative long QT syndrome (LQTS) patients without aborted cardiac arrest (ACA) before diagnosis or cardiac events (CEs) below age 1
- Participants
- 946 participants
- Outcome
- Appropriateness of adherence to M-FACT risk score suggestions (M-FACT ≥2, static or dynamic)
Main finding
As reported in the abstract
- Persistent dynamic M-FACT ≥2 after further therapeutic optimization: patients with CEs (no ACA)
- 7 (14%) of 49
- Remaining static M-FACT ≥2 patients on βB with CEs
- 0 of 57
- New dynamic M-FACT ≥2 after therapeutic optimization: patients with CEs
- 3 (9%) of 32
- Implantable cardioverter defibrillator (ICD) implanted among patients indicated by M-FACT ≥2
- 22/142 (15%)
- Patients with ICD shocks
- 3
Observational data: associations, not effects.
Further findings
QTc ≥500 ms before vs on βB
- QTc ≥500 ms reduced with βB (94% treated)
- 18% to 12% (P < .001)
Overall outcomes · 7 ± 6 years of follow-up
- Deaths
- 0
- CEs
- 4%
- ACA
- 0.4%
Original publication
Long QT syndrome: importance of reassessing arrhythmic risk after treatment initiation. Eur Heart J. Published 16 May 2024. doi:10.1093/eurheartj/ehae289
Summarised from the published abstract; every number is checked against it