Upgrading to CRT-D significantly increased the odds of echocardiographic response compared to ICD alone (OR 5.57; 95% CI 2.56-12.12; p<0.001) in HFrEF patients with prior RV pacing.
RCT (n=360)
3:2
Does upgrading to CRT-D improve the composite of mortality, heart failure hospitalization, or LVESV reduction in HFrEF patients with a pacemaker or ICD and ≥20% RV pacing burden compared to ICD alone?
Upgrading to CRT-D in HFrEF patients with high RV pacing burden significantly improves echocardiographic response, with higher odds of response seen in those with non-ischemic etiology, higher RV pacing burden, and lateral LV lead location.
Odds Ratio: 5.57 (95% CI 2.56–12.12)
p-value: p=<0.001
Abstract Background De novo and upgrade to cardiac resynchronization therapy (CRT) effectively reduces morbidity and mortality. However, non-response to CRT may occur up to 30%, as non-response remains relevant, assessment of its predictors is crucial. Objectives We sought to examine the predictors of response after upgrading from right ventricular to biventricular pacing in the BUDAPEST-CRT Upgrade trial cohort. Methods HFrEF patients with a pacemaker or implantable cardioverter defibrillator (ICD) and ≥20% RV pacing burden were randomly assigned (3:2) to CRT-D upgrade (n=215) or ICD (n=145). The primary outcome was the composite of all-cause mortality, heart failure hospitalization, or 15% reduction of left ventricular end-systolic volume (LVESV) assessed at 12 months. We defined echocardiographic response based on a ›15% reduction of LVESV and super response if it is ›30%. Results Altogether, LVESV change was available in 275 (76%) patients, of these 161 (58%) patients were responders, of which 92 (34%) superresponder. Responders were less likely to experience multiple HF hospitalizations (0.6% vs. 7%; p=0.003) and experienced a higher RV pacing burden at enrolment (88.9% vs. 83.4%; p=0.026). Responder status was associated with being on the CRT-D arm (OR 5.57; 95% CI 2.56-12.12; p‹0.001), RV pacing burden (OR 1.02; 95% CI 1.00-1.04; p=0.024), ischemic etiology (OR 0.40; 95%CI 0.19-0.87; p= 0.021) and lateral LV lead location (OR 8.79; 95% CI 1.28-60.34; p=0.027). Almost half of the patients in the CRT-D arm (49%) were proved to be superresponders. Conclusions Even though the beneficial effect of CRT upgrade was observed across all specified subgroups, patients with non-ischemic etiology, higher RV pacing burden and lateral LV lead location had higher odds to experience echocardiographic response to therapy. The observed proportion of superresponders was higher as compared to previous de novo CRT trials’ populations.
Merkely et al. (2025) conducted an RCT in Heart failure with reduced ejection fraction (HFrEF) and high right ventricular pacing burden (n=360). CRT-D upgrade vs. ICD was evaluated on Composite of all-cause mortality, heart failure hospitalization, or <15% reduction of left ventricular end-systolic volume (LVESV) assessed at 12 months (OR 5.57, 95% CI 2.56-12.12, p=<0.001). Upgrading to CRT-D significantly increased the odds of echocardiographic response compared to ICD alone (OR 5.57; 95% CI 2.56-12.12; p<0.001) in HFrEF patients with prior RV pacing.