Comparison of ventricular arrhythmia burden, therapeutic interventions, and survival, in patients < 75 and patients >or= 75 years of age treated with implantable cardioverter defibrillators.
OBJECTIVE
Implantable cardioverter defibrillators (ICD) reduce arrhythmic mortality in a wide range of patients with poor left ventricular (LV) function. However, whether ICD therapy is equally effective in younger and older patients remains uncertain. To address this question, we compared ICD-documented ventricular tachyarrhythmia burden in patients < 75 years of age (Group 1) and >or= 75 years of age (Group 2).


METHODS
Data were obtained from 208 consecutive ICD-treated patients: 159 Group 1 (mean age 59 +/- 12), and 49 Group 2 (mean age 79 +/- 3). Demographic and clinical features including presenting arrhythmias, LV ejection fraction, and nature of heart disease were similar. Medications were comparable except that amiodarone use was more frequent in Group 2.


RESULTS
The numbers of combined ventricular tachycardia (VT) and ventricular fibrillation (VF) episodes per month were 0.4 +/- 2 and 0.3 +/- 2 for groups 1 and 2, respectively (P = 0.7). Individually, VT episodes per month were 0.4 +/- 2 and 0.3 +/- 2 (P = 0.7) and VF episodes per month were 0.003 +/- 0.01 and 0.03 +/- 0.2 (P = 0.2) for the two groups, respectively. The mean duration and average cycle length of arrhythmias were 3.1 +/- 20.4 s and 275 +/- 119 ms in Group 1, and 6 +/- 45 s and 285 +/- 114 ms in Group 2 (P values, 0.6 and 0.8). The mean time between the ICD implantation and the first episode of a device-treated arrhythmia was comparable in the two groups. Thirty-six patients died during follow-up; 22 (14%) Group 1 and 14 (29%) Group 2 (P = 0.02), almost exclusively on a non-sudden cardiac basis. Thus, despite higher ultimate mortality in older patients, both the nature and characteristics of spontaneous arrhythmia recurrence, and the time to first apparently beneficial therapy, were similar during follow-up in the two groups.


CONCLUSIONS
In terms of reversing potentially life-threatening arrhythmias, the rationale for ICD therapy is comparable in older and younger individuals.
Ermis
Cengiz
C
Cardiovascular Division, University of Akdeniz, Antalya, Turkey.
Zhu
Alan X
AX
Vanheel
Laura
L
Sakaguchi
R N Scott
RN
Lurie
Keith G
KG
Lu
Fei
F
Benditt
David G
DG
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D012720:Severity of Illness Index; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000503:physiopathology; D014693:Ventricular Fibrillation / Q000503:physiopathology