Heart failure & cardiomyopathies
Lateral QRS amplitude is independently associated with outcome after cardiac resynchronization therapy: Advancing patient selection?
Authors' conclusion
Low QRS amplitude in lateral electrocardiogram leads is associated with higher risk of poor outcome in CRT patients. A cutoff of 3 mV in lead V6 proved highly discriminative.
Study context
- Population
- HF patients undergoing cardiac resynchronization therapy (CRT); intrinsic pre-implantation QRS amplitude
- Participants
- 178 vs 183
- Exposure
- Baseline lateral QRS amplitude and outcome after CRT
- Zurichn = 178
- Leuvenn = 183
- Outcome
- Composite of:
- All-cause mortality
- Ventricular assist device implantation
- Heart transplantation
- Follow-up
- 5 years
Methodological detailsmultinational, 2-center, derivation and validation cohorts
- Multinational
- 2-center
- Derivation and validation cohorts
Main finding
As reported in the abstract
Composite end point per millivolt higher baseline to peak amplitude in lateral leads
Hazard ratio, per millivolt (95% CI)P value
Lead I amplitude
0.86(0.78–0.95)
P = 0.002Lead V6 amplitude
0.94(0.88–1.00)
P = 0.043Per millivolt, as printed
Observational data: associations, not effects.
Further findings
Optimal cutoff values for discrimination of outcome
- Suggested cutoff lead I
- 6 mV
- Suggested cutoff V6
- 3 mV
- Concordance index-based comparison of quartile, spline and ROC curve analysis
External validation of 3 mV cutoff in lead V6
- Highly significant discriminator of outcome
- P < 0.001
- Risk reduction
- 65%
Original publication
Lateral QRS amplitude is independently associated with outcome after cardiac resynchronization therapy: Advancing patient selection? Heart Rhythm. Published 22 October 2024. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →