Heart failure & cardiomyopathiesCohort study
Normalized QRS Duration by LV Dimension
- multicenter retrospective study
Authors' conclusion
QRSd/LVEDD effectively eliminated sex-specific differences in CRT efficacy and outperformed QRSd in predicting clinical outcomes. Sex did not directly influence CRT outcomes but mediated its effect indirectly through QRSd/LVEDD.
Study context
- Population
- Patients with heart failure who underwent biventricular or left bundle branch area pacing for resynchronization therapypatients screened
- Participants
- 602 patients
- Exposure
- Female vs male patients, with and without adjustment for QRS duration (QRSd)/LVEDD
- female patientsn = 216
- Outcome
- Primary composite outcome:
- All-cause mortality
- Heart failure hospitalizations
- Ventricular tachyarrhythmic events (clinical outcomes)
Main finding
As reported in the abstract
Sex-specific difference in clinical outcomes, initially observed
HR: 1.71; 95% CI: 1.17-2.48; P = 0.005
Sex-specific difference after QRSd/LVEDD (eliminated)
HR: 1.14; 95% CI: 0.76-1.69; P = 0.527
Dose-response relationship
P < 0.001
Observational data: associations, not effects.
Further findings
| Outcome | female patients | male patients |
|---|---|---|
| QRSd/LVEDD ratio | 2.66 | 2.48 |
- QRSd/LVEDD ratio: P < 0.001
Left ventricular ejection fraction improvement
- After QRSd/LVEDD adjustment, female patients no longer exhibited greater left ventricular ejection fraction improvement
Prognostic stratification by QRSd/LVEDD within each sex group
- QRSd/LVEDD stratified prognosis within each sex group
- P < 0.001
Sex-specific differences among patients with the same QRSd/LVEDD
- QRSd/LVEDD ≥2.55
- P = 0.744
- QRSd/LVEDD <2.55
- P = 0.123
Structural equation modeling
- Direct influence of sex on clinical outcomes
- P = 0.693
- Indirect effect of sex through QRSd/LVEDD
- P < 0.001
Prediction of clinical outcomes
- QRSd/LVEDD exhibited superior ability to predict clinical outcomes compared with QRSd and was integrated into machine learning modeling for individualized cardiac resynchronization therapy (CRT) risk prediction
Original publication
Summarised from the published abstract; every number is checked against it