Among patients with LVEF ≤20% and QRS ≥130 ms, CRT-D significantly reduced the 3-year rate of heart failure or death compared to ICD in those with LBBB (20% vs 40%; HR 0.46, p<0.001).
Cohort (n=820)
Yes
Does CRT-D reduce the composite of heart failure or death compared to ICD in patients with LVEF ≤20% and QRS ≥130 ms?
CRT-D provides significant clinical benefits over ICD in patients with advanced left ventricular dysfunction (LVEF ≤20%) and a wide QRS complex, but this benefit is restricted to those with left bundle branch block (LBBB).
Hazard Ratio: 0.46
Absolute Event Rate: 20% vs 40%
p-value: p=<0.001
Abstract Background Limited data exist on the effects of cardiac resynchronization therapy with defibrillator (CRT-D) on clinical outcomes in patients with advanced left ventricular dysfunction. Purpose This study aimed to evaluate the clinical benefits of CRT-D compared with an implantable cardioverter defibrillator (ICD) in patients with very low left ventricular ejection fraction (LVEF ≤20%) and a wide QRS complex. Methods This study included 820 patients with LVEF ≤20% and QRS duration ≥130 ms, enrolled in five major trials (MADIT-II, MADIT-CRT, MADIT-RIT, MADIT-RISK, RAID). The primary outcome was a composite of heart failure (HF) or death. Secondary outcomes included death, first HF event, recurrent HF, ventricular tachycardia or fibrillation (VT/VF), and appropriate ICD shocks. Outcomes were stratified by the presence of left bundle branch block (LBBB). Results Among 508 CRT-D patients (70% LBBB) and 364 ICD patients (72% LBBB), CRT-D vs. ICD was associated with a significant reduction in the 3-year cumulative event rate of HF or death in LBBB patients (20% vs. 40%, p0.001 Figure Panel A) but not in non-LBBB patients (37% vs. 42%, p=0.499 Figure Panel B). Multivariate analysis showed that CRT-D significantly reduced HF or death in LBBB patients (HR=0.46, p0.001) but showed no benefit in non-LBBB patients (HR=1.16, p=0.566; p-value for interaction =0.001). Similarly, in LBBB patients, CRT-D was associated with reductions in death (HR=0.60, p=0.069), first HF event (HR=0.42, p0.001), recurrent HF (HR=0.39, p0.001), VT/VF (HR=0.64, p=0.011), and appropriate ICD shocks (HR=0.35, p0.001). In contrast, CRT-D did not significantly reduce any of these outcomes in non-LBBB patients (p0.1 for all comparisons; p for interaction device-by-LBBB 0.05 for all). Conclusions CRT-D provides significant clinical benefits in patients with advanced left ventricular dysfunction and LBBB. These findings should be considered when evaluating the need for advanced HF intervention therapies in this population.
Golovchiner et al. (2025) conducted a cohort in advanced left ventricular dysfunction and a wide QRS (n=820). Cardiac resynchronization therapy with defibrillator (CRT-D) vs. Implantable cardioverter defibrillator (ICD) was evaluated on composite of heart failure (HF) or death (HR 0.46, p=<0.001). Among patients with LVEF ≤20% and QRS ≥130 ms, CRT-D significantly reduced the 3-year rate of heart failure or death compared to ICD in those with LBBB (20% vs 40%; HR 0.46, p<0.001).