Atrial fibrillation predicts appropriate shocks in primary prevention implantable cardioverter-defibrillator patients.
OBJECTIVE
Atrial fibrillation (AF) is often present in patients with left ventricular dysfunction who receive an implantable cardioverter-defibrillator (ICD). The purpose of this study was to investigate whether AF is associated with appropriate shocks and cardiovascular mortality in primary prevention ICD patients with left ventricular dysfunction.


RESULTS
We included 80 primary prevention ICD patients with left ventricular dysfunction and compared the outcome between patients with a history of AF (n=29) and patients with no history of AF (n=51). The primary endpoint was occurrence of appropriate shocks. Secondary endpoints were: (1) the composite of cardiovascular mortality/appropriate shocks; and (2) inappropriate shocks. During follow-up (median 8 months, range 1-60), patients with a history of AF more often received appropriate shocks than patients with no history of AF (24 vs. 6%, P=0.03). The composite endpoint of cardiovascular mortality/appropriate shocks was also more likely to occur in patients with a history of AF (34 vs. 12%, P=0.02). History of AF predicted appropriate shocks (HR 6.9, 95% CI 1.7-27.5, P=0.006) and the composite endpoint of cardiovascular mortality/appropriate shocks (adjusted HR 5.1, 95% CI 1.7-15.1, P=0.003). There were no differences in occurrence of inappropriate shocks.


CONCLUSIONS
Our study demonstrates that history of AF is associated with increased risk of appropriate shocks and cardiovascular mortality in primary prevention ICD patients with left ventricular dysfunction.
Smit
Marcelle D
MD
Department of Cardiology, Thoraxcenter, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands.
Van Dessel
Pascal F H M
PF
Rienstra
Michiel
M
Nieuwland
Wybe
W
Wiesfeld
Ans C P
AC
Tan
Eng S
ES
Anthonio
Rutger L
RL
Van Veldhuisen
Dirk J
DJ
Van Gelder
Isabelle C
IC
D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology*; D002318:Cardiovascular Diseases / Q000401:mortality; D017147:Defibrillators, Implantable; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011322:Primary Prevention / Q000379:methods*; D012189:Retrospective Studies; D012307:Risk Factors; D012770:Shock, Cardiogenic / Q000503:physiopathology*; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology / Q000628:therapy