Patient-specific modifiers of survival benefit in cardiac resynchronization therapy - A multicentre interaction
Bert Vandenberk1,2, Marius Brusselmans3, Gabor Voros1,2
1Department of Cardiology, UZ Leuven, Leuven, Belgium.
Insights
Cardiac resynchronization therapy with a defibrillator (CRT-D) significantly reduces mortality compared to a pacemaker (CRT-P). Key patient factors like LBBB morphology, ejection fraction, and renal function influence CRT-D benefit.
Area of Science:
- Cardiology
- Medical Devices
- Clinical Trials
Background:
- Cardiac resynchronization therapy (CRT) is crucial for heart failure management.
- Selecting between CRT with defibrillator (CRT-D) and CRT with pacemaker (CRT-P) depends on patient specifics.
- This study investigates how clinical variables modify CRT-D versus CRT-P benefits on mortality.
Purpose of the Study:
- To analyze the impact of clinical characteristics on all-cause mortality in CRT patients.
- To determine how specific patient factors influence the comparative effectiveness of CRT-D versus CRT-P.
- To identify patient subgroups that derive maximal survival benefit from CRT-D.
Main Methods:
- Retrospective analysis of 2271 patients from three European centers undergoing CRT implantation.
- Utilized multivariable Cox proportional hazard models with interaction tests to assess mortality.
- Explored interactions between clinical variables and the choice between CRT-D and CRT-P.
Main Results:
- CRT-D showed a 35% reduction in all-cause mortality versus CRT-P (HR 0.65).
- Significant interactions identified for left bundle branch block (LBBB) morphology, left ventricular ejection fraction (LVEF), and renal function.
- CRT-D benefit was most pronounced in patients with LBBB, specific LVEF ranges, and adequate renal function.
Conclusions:
- Left bundle branch block morphology, LVEF, and renal function are key predictors of CRT-D benefit over CRT-P.
- These factors help personalize treatment decisions for patients receiving CRT.
- Implantable cardioverter-defibrillator therapy component of CRT-D offers survival advantages in selected heart failure patients.
Background:
Cardiac resynchronization therapy (CRT) is a key intervention for patients with heart failure. The choice between a CRT with defibrillator therapy (CRT-D) and a CRT with pacemaker (CRT-P) is influenced by individual clinical characteristics. This study explores the interaction between these clinical variables and the benefit of CRT-D versus CRT-P on all-cause mortality.
Methods:
All patients who underwent CRT implantation in three European centres were included in a multicentre, retrospective registry. The impact of clinical variables on all-cause mortality was analysed using interaction tests within multivariable Cox proportional hazard models. Significant interactions were explored to assess how patient characteristics modify the effect of CRT-D compared with CRT-P.
Results:
A total of 2271 patients with CRT implantation were included. CRT-D was associated with a 35% reduction in all-cause mortality compared with CRT-P [hazard ratio (HR) 0.65; 95% confidence interval (CI) 0.53-0.80]. Significant interactions were observed for left bundle branch block (LBBB) morphology (P = 0.028), left ventricular ejection fraction (LVEF, P = 0.025) and renal function (P = 0.019). The survival benefit of CRT-D was pronounced in patients with LBBB (HR 0.57; 95% CI 0.44-0.73) but was not significant in those without LBBB (HR 0.81; 95% CI 0.59-1.10). For LVEF at implant, CRT-D provided benefit between 17.9% and 37.6%. Similarly, CRT-D improved outcomes in patients with an estimated glomerular filtration rate >31.8 mL/min but not in those with more advanced renal impairment. No interaction was observed with age at implant (P = 0.286).
Conclusions:
This study provides insights into the benefits of CRT-D over CRT-P, identifying LBBB morphology, LVEF and renal function as key covariates associated with implantable cardioverter-defibrillator (ICD) therapy's benefit.
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