Reduced appropriate implantable cardioverter-defibrillator therapy after cardiac resynchronization therapy-induced left ventricular function recovery: a meta-analysis and systematic review.
OBJECTIVE
For patients undergoing cardiac resynchronization therapy (CRT) with implantable cardioverter-defibrillator (ICD; CRT-D), the effect of an improvement in left ventricular ejection fraction (LVEF) on appropriate ICD therapy may have significant implications regarding management at the time of ICD generator replacement.


RESULTS
We conducted a meta-analysis to determine the effect of LVEF recovery following CRT on the incidence of appropriate ICD therapy. A search of multiple electronic databases identified 709 reports, of which 6 retrospective cohort studies were included (n = 1740). In patients with post-CRT LVEF ≥35% (study n = 4), the pooled estimated rate of ICD therapy (5.5/100 person-years) was significantly lower than patients with post-CRT LVEF <35% [incidence rate difference (IRD): -6.5/100 person-years, 95% confidence interval (95% CI): -8.8 to -4.2, P < 0.001]. Similarly, patients with post-CRT LVEF ≥45% (study n = 4) demonstrated lower estimated rates of ICD therapy (2.3/100 person-years) compared with patients without such recovery (IRD: -5.8/100 person-years, 95% CI: -7.6 to -4.0, P < 0.001). Restricting analysis to studies discounting ICD therapies during LVEF recovery (study n = 3), patients with LVEF recovery (≥35 or ≥45%) had significantly lower rates of ICD therapy compared with patients without such recovery (P for both <0.001). Patients with primary prevention indication for ICD, regardless of LVEF recovery definition, had very low rates of ICD therapy (0.4 to 0.8/100-person years).


CONCLUSIONS
Recovery of LVEF post-CRT is associated with significantly reduced appropriate ICD therapy. Patients with improvement of LVEF ≥45% and those with primary prevention indication for ICD appear to be at lowest risk.
Department of Medicine and the Cardiac Arrhythmia Service, GRB 109, Massachusetts General Hospital Heart Center, 55 Fruit Street, Boston, MA 02411, USA.
Neal A
NA
Chatterjee
Department of Medicine and the Cardiac Arrhythmia Service, GRB 109, Massachusetts General Hospital Heart Center, 55 Fruit Street, Boston, MA 02411, USA.
Attila
A
Roka
Department of Medicine and the Cardiac Arrhythmia Service, GRB 109, Massachusetts General Hospital Heart Center, 55 Fruit Street, Boston, MA 02411, USA.
Steven A
SA
Lubitz
Division of Cardiology, Medical University of South Carolina, Charleston, SC, USA.
Michael R
MR
Gold
Cardiology Division, Rennes University Hospital, Rennes, France.
Claude
C
Daubert
Department of Cardiology, Karolinska University Hospital, Stockholm, Sweden.
Cecilia
C
Linde
Department of Cardiology, University Hospital Zurich, Zurich, Switzerland.
Jan
J
Steffel
Department of Medicine and the Cardiac Arrhythmia Service, GRB 109, Massachusetts General Hospital Heart Center, 55 Fruit Street, Boston, MA 02411, USA.
Jagmeet P
JP
Singh
Department of Medicine and the Cardiac Arrhythmia Service, GRB 109, Massachusetts General Hospital Heart Center, 55 Fruit Street, Boston, MA 02411, USA tmela@mgh.harvard.edu.
Theofanie
T
Mela
D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D005260:Female; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D020127:Recovery of Function / Q000502:physiology; D013318:Stroke Volume / Q000502:physiology; D017180:Tachycardia, Ventricular / Q000503:physiopathology / Q000628:therapy; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology / Q000628:therapy*
Meta-analysis; Resynchronization; Ventricular tachyarrhythmia