Heart failure & cardiomyopathies
Horizontal QRS axis predicts response to cardiac resynchronization therapy in heart failure patients with left bundle branch block
Authors' conclusion
Horizontal QRS axis accurately predicts CRT response and prognosis in HF patients with LBBB.
Study context
- Population
- Heart failure (HF) patients with left bundle branch block (LBBB) receiving cardiac resynchronization therapy (CRT) (consecutive CRT recipients)
- Participants
- 244 consecutive CRT recipients
- Exposure
- CRT responders vs nonresponders
- Respondersn = 156
- Nonrespondersn = 88reference
- Outcome
- CRT response (≥10% increase in LVEF and ≥1 NYHA class reduction)
- Follow-up
- 1 year after CRT implantation
Methodological detailsconsecutive CRT recipients
- Consecutive CRT recipients
Main finding
As reported in the abstract
Horizontal QRS axis prediction of CRT response
| Group | Value | Direction |
|---|---|---|
| Responders | mean 35.5 (SD 10.9) mm | −75.5° [−79.7° to −69.0°] |
| Nonresponders | mean 25.5 (SD 10.5) mm | −65.0° [−73.0° to −46.5°] |
Value
Respondersmean 35.5 (SD 10.9) mm
Nonrespondersmean 25.5 (SD 10.5) mm
Direction
Responders−75.5° [−79.7° to −69.0°]
Nonresponders−65.0° [−73.0° to −46.5°]
- Responders vs Nonresponders: P < 0.001 — direction
- Responders vs Nonresponders: P < 0.001 — magnitude
- AUC, direction
- 0.778 (95% CI, 0.717-0.839)
- AUC, magnitude
- 0.749 (95% CI, 0.685-0.814)
- AUC, combined
- 0.814 (95% CI, 0.760-0.868)
Observational data: associations, not effects.
Further findings
| Outcome | HR (95% CI) | |
|---|---|---|
| HF hospitalization or all-cause mortality — Direction vs Nonresponders | 0.36 (0.22–0.60) | |
| HF hospitalization or all-cause mortality — Magnitude vs Nonresponders | 0.41 (0.25–0.67) | |
| HF hospitalization or all-cause mortality — Combination vs Nonresponders | 0.25 (0.15–0.41) | |
| 0.10.31310Hazard ratio (log scale) |
Original publication
Horizontal QRS axis predicts response to cardiac resynchronization therapy in heart failure patients with left bundle branch block. Heart Rhythm. Published 12 November 2024. doi:10.
Summarised from the published abstract; every number is checked against it