the Benefits of Additional Defibrillator in Heart Failure Patients with
Cardiac Resynchronization Therapy: A Meta-analysis of Observational
Studies
Abstract
Abstract Background: Current guidelines did not provide recommendations
on indications of an additional implantable cardioverter-defibrillator
(ICD) to patients receiving cardiac resynchronization therapy (CRT), and
it still remains controversial due to lack of evidence from randomized
controlled trials (RCTs). Method: PubMed, Embase and Cochrane CENTRAL
from the inception to May 2020 were systematically screened for studies
reporting on the comparison of CRT-defibrillator (CRT-D) and
CRT-pacemaker (CRT-P), focusing on the adjusted hazard ratio (aHR) of
all-cause mortality. We pooled the effects using a random-effect model.
Results: Twenty-one studies encompassing 69919 patients were included in
this meta-analysis. With no restriction to characteristics of including
population, CRT-D was associated with a lower all-cause mortality
compared with CRT-P significantly (aHR: 0.79, 95%CI: 0.72-0.88,
I2=40.5%, P<0.0001). This mortality benefit was also observed
in patients with ischemic cardiomyopathy (ICM) (HR: 0.74, 95%CI:
0.64-0.86, I2=0%, P<0.0001). However, there is no significant
difference in patients with non-ischemic cardiomyopathy (NICM) (HR:
0.91, 95%CI: 0.82-1.01, I2=0%, P=0.087), older age (age ≥75 years,
aHR: 0.96, 95%CI: 0.83-1.12, I2=0%, P=0.610). Subgroup analysis was
performed and indicated that there is no mortality benefit of CRT-D for
primary prevention (aHR: 0.92, 95%CI: 0.74-1.14, I2=0%, P=0.444).
Conclusion: After adjusted the differences in clinical characteristics,
additional ICD therapy was associated with a reduced all-cause mortality
in patients receiving CRT, especially in patients with ICM. However, our
work suggested that additional ICD may not be applied to elderly, NICM
patients or for primary prevention. Keyword: heart failure; cardiac
resynchronization therapy; defibrillator; all-cause mortality;
meta-analysis