An impaired renal function and advanced heart failure represent independent predictors of the incidence of malignant ventricular arrhythmias in patients with an implantable cardioverter/defibrillator for primary prevention.
OBJECTIVE
Malignant ventricular arrhythmias and inappropriate therapies represent unsolved problems in patients with implantable cardioverter/defibrillator (ICD) for primary prevention. This study focuses on the incidence of such therapies and thereby seeks to identify new predictors of adverse events to enhance risk stratification.


RESULTS
Ninety-four consecutive patients with mild-to-moderate heart failure (NYHA II-III) and depressed left ventricular function (≤35%) were followed for 34 ± 20 months. Two hundred and ninety-one malignant ventricular arrhythmias were documented in 51 patients (54%). Eighteen patients (19%) received inappropriate ICD therapies (e.g. atrial fibrillation, sinus tachycardia, etc.). Patients with malignant arrhythmia (1.34 ± 0.44 vs. 1.16 ± 0.4 mg/dL, P = 0.017) and patients suffering from inappropriate ICD therapies (1.54 ± 0.48 vs. 1.2 ± 0.38 mg/dL; P = 0.007) revealed a significantly worse renal function before ICD implantation than participants without any therapy. An increased serum creatinine at baseline (2 vs. 1 mg/dL; odds ratio (OR) 3.96; P = 0.02; 95% CI: 1.2-13.04) and NHYA class III compared with II (OR: 2.96; P = 0.02; 95% CI: 1.16-7.48) represent strong and independent predictors for the occurrence of ventricular arrhythmias. Moreover, an impaired renal function is identified as an independent risk factor for inappropriate therapies (OR: 5.6; P = 0.004; 95% CI: 1.72-18.22).


CONCLUSIONS
An impaired renal function and advanced heart failure before ICD implantation for primary prevention are identified as independent predictors for the incidence of appropriate ICD interventions. With regard to current guidelines and economical aspects, patients suffering from an impaired renal function or advanced heart failure seem to benefit most from ICD therapy.
Kreuz
Jens
J
Department of Medicine-Cardiology, University of Bonn, Sigmund-Freud-Street 25, 53105 Bonn, Germany. jens.kreuz@ukb.uni-bonn.de
Balta
Osman
O
Linhart
Markus
M
Fimmers
Rolf
R
Lickfett
Lars
L
Mellert
Fritz
F
Nickenig
Georg
G
Schwab
Joerg Otto
JO
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood; D017147:Defibrillators, Implantable; D006333:Heart Failure / Q000150:complications / Q000453:epidemiology* / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D051437:Renal Insufficiency / Q000150:complications / Q000453:epidemiology* / Q000503:physiopathology; D012189:Retrospective Studies; D012307:Risk Factors; D018487:Ventricular Dysfunction, Left / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy
D003404:Creatinine