Heart failure & cardiomyopathies
QRS Morphology and the Risk of Ventricular Tachyarrhythmia in Cardiac Resynchronization Therapy Recipients
Authors' conclusion
Our data suggest a potential proarrhythmic effect of CRT among patients with NLBBB.
Study context
- Population
- Patients with QRS duration ≥130 ms implanted with ICD/cardiac resynchronization therapy with a defibrillator (CRT-D) for primary prevention in MADIT-II, MADIT-CRT, MADIT-RIT, MADIT-RISK and RAID
- Participants
- 2,862 patients · 5 trials
- Comparison
- CRT-D vs ICD only, by QRS morphology
- Outcome
- Fast ventricular tachycardia (VT)/ventricular fibrillation (VF) (VT ≥200 beats/min or VF), accounting for the competing risk of death
Methodological detailscompeting-risk analysis, recurrent event analysis
- Competing-risk analysis
- Recurrent event analysis
Pooled result
As reported in the abstract
Fast VT/VF, by QRS morphology (subgroups)
- LBBB (n = 1,792; CRT-D n = 1,112, ICD only n = 680)
- risk reduction 44%; P < 0.001
- Non-left bundle branch block (NLBBB) (N = 1,070); no reduction
- HR 1.33; P = 0.195
Further pooled results
| Outcome | HR | P value |
|---|---|---|
| Burden of fast VT/VF, by QRS morphology — CRT-D vs ICD only · LBBB · recurrent event analysis | 0.55 | P = 0.001 |
| Burden of fast VT/VF, by QRS morphology — CRT-D vs ICD only · NLBBB; increased burden · recurrent event analysis | 1.90 | P = 0.013 |
| Burden of appropriate shocks (LBBB) · LBBB | 0.44 | P < 0.001 |
Original publication
QRS Morphology and the Risk of Ventricular Tachyarrhythmia in Cardiac Resynchronization Therapy Recipients. JACC Clin Electrophysiol. Published 29 November 2023. doi:10.
Summarised from the published abstract; every number is checked against it