(NVKP-16-1-2016-0017 National Heart Program) Funder: NRDIO
(RRF-2.3.1-21-2022-00003)
(János Bolyai Research Scholarship)
De novo implanted cardiac resynchronisation therapy with defibrillator (CRT-D) reduces
the risk of morbidity and mortality in patients with left bundle branch block, heart
failure and reduced ejection fraction (HFrEF). However, among HFrEF patients with
right ventricular pacing (RVP), the efficacy of CRT-D upgrade is uncertain.In this
multicentre, randomised, controlled trial, 360 symptomatic (New York Heart Association
class II-IVa) HFrEF patients with a pacemaker or implantable cardioverter defibrillator
(ICD), high RVP burden ≥20%, and a wide, paced QRS complex duration ≥150 ms were randomly
assigned to receive CRT-D upgrade (n = 215) or ICD (n = 145) in a 3:2 ratio. The primary
outcome was the composite of all-cause mortality, heart failure hospitalisation or
<15% reduction of left ventricular end-systolic volume assessed at 12 months. Secondary
outcomes included all-cause mortality or heart failure hospitalisation.Over a median
follow-up of 12.4 months, the primary outcome occurred in 58/179 (32.4%) in the CRT-D
arm vs. 101/128 (78.9%) in the ICD arm [odds ratio 0.11; 95% confidence interval (CI)
0.06-0.19; p < 0.001]. All-cause mortality or heart failure hospitalization occurred
in 22/215 (10%) in the CRT-D arm vs. 46/145 (32%) in the ICD arm (hazard ratio 0.27;
95% CI 0.16-0.47; p < 0.001). The incidence of procedure- or device-related complications
was similar between the two arms [CRT-D group 25/211 (12.3%) vs. ICD group 11/142
(7.8%)].In pacemaker or ICD patients with significant RVP burden and reduced ejection
fraction, upgrade to CRT-D compared to ICD therapy reduced the combined risk of all-cause
mortality, heart failure hospitalisation or absence of reverse remodelling.
