The Age Paradox in ICD Testing:
A Study on Inadequate Safety Margins and
Long-term Appropriate Therapy
J.L. Bonnes1, S.W. Westra1, E.S. Zegers2, M.A. Brouwer1, J.L.R.M. Smeets1
1 Radboud
2 Canisius
UMC Nijmegen
Wilhelmina Hospital Nijmegen
No conflicts of interest
Introduction
• Routine defibrillation testing after ICD implantation is subject of debate
• Testing allows identification of patients with inadequate safety margins
who may benefit from system modifications
• Testing after all implants vs. patient-tailored testing
• Non-invasive identification of patients at increased risk of an inadequate
safety margin: conflicting results with regard to age
• Previous studies did not account for the underlying cardiac disease
2
Aim 1
• Percentage inadequate safety margins in relation to age
• Ischemic – Nonischemic heart disease
3
Aim 2
• Percentage appropriate ICD therapy in relation to age
• Ischemic – Nonischemic heart disease
Methods
• Patient population:
•
Consecutive patients who underwent a first ICD implantation in the Radboud
UMC between 2005 and 2013
•
Exclusion criteria:
• Age < 18 years
• Right-sided ICD implantation
• Congenital heart disease
• No defibrillation test performed
5
Methods
• Defibrillation testing:
•
•
VF induction
Consecutive ICD test shocks of 15-25-35 Joule
• Patient groups:
•
•
Ischemic vs. nonischemic heart disease
Age groups (tertiles: <59 yrs, 59-70 yrs, ≥70 yrs)
• End points:
•
•
Inadequate defibrillation safety margin
Appropriate ICD therapy
6
Methods
• ICD programming:
•
•
VF detection zone
One or two VT detection zones
• Follow-up:
•
•
Routine follow-up at the outpatient clinic
In case of ICD therapy, appropriateness was assessed
7
Results: Entire population
• A total of 732 patients was studied:
 456 (62%) with ischemic heart disease
 276 (38%) with nonischemic heart disease
8
Results: Age groups in ischemic heart disease
Age <59 years
Age 59-70 years
Age ≥70 years
n=114
n=172
n=170
Age (yrs)
51 ± 6
64 ± 3
75 ± 4
<0.01
Male gender
81 (71)
139 (81)
154 (91)
<0.01
CRT-D
21 (18)
43 (25)
50 (29)
0.11
LVEF (%)
32 ± 12
31 ± 12
30 ± 10
0.60
LVIDd-index (cm/m2)
3.1 ± 0.6
3.2 ± 0.6
3.1 ± 0.4
0.41
QRS duration (ms)
111 ± 22
123 ± 25
127 ± 30
<0.01
Beta blocker
111 (97)
160 (94)
147 (87)
<0.01
Amiodarone
10 (9)
25 (15)
33 (19)
0.05
9
P-value
Results: Age groups in nonischemic heart disease
Age <59 years
Age 59-70 years
Age ≥70 years
n=131
n=88
n=57
Age (yrs)
45 ± 10
64 ± 3
74 ± 3
<0.01
Male gender
84 (64)
55 (63)
43 (75)
0.23
CRT-D
40 (31)
39 (44)
32 (56)
<0.01
LVEF (%)
36 ± 17
31 ± 16
30 ± 10
0.05
LVIDd-index (cm/m2)
3.0 ± 0.6
3.1 ± 0.6
3.3 ± 0.5
<0.01
QRS duration (ms)
116 ± 30
135 ± 35
143 ± 32
<0.01
Beta blocker
109 (83)
78 (89)
49 (86)
0.53
Amiodarone
8 (6)
10 (11)
4 (7)
0.36
10
P-value
Results: Shock outcomes and appropriate therapy
Age <59 yrs
Age 59-70 yrs
Age ≥70 yrs
Entire population
Inadequate safety margin
Appropriate ICD therapy
n=245
7%
15%
n=260
2%
25%
n=227
2%
26%
Ischemic heart disease
n=114
n=172
n=170
Inadequate safety margin
3%
2%
3%
0.94
Appropriate ICD therapy*
14%
28%
29%
<0.01
n=131
n=88
n=57
Inadequate safety margin
12%
2%
0%
<0.01
Appropriate ICD therapy*
16%
17%
17%
0.83
Nonischemic heart disease
* Time to first appropriate ICD therapy was compared with the log-rank test
11
P-value
<0.01
0.02
Results: Shock outcomes and appropriate therapy
Age <59 yrs
Age 59-70 yrs
Age ≥70 yrs
Entire population
Inadequate safety margin
Appropriate ICD therapy
n=245
7%
15%
n=260
2%
25%
n=227
2%
26%
<0.01
0.02
Ischemic heart disease
Inadequate safety margin
Appropriate ICD therapy
n=114
3%
14%
n=172
2%
28%
n=170
3%
29%
0.94
<0.01
Nonischemic heart disease
n=131
n=88
n=57
Inadequate safety margin
12%
2%
0%
<0.01
Appropriate ICD therapy*
16%
17%
17%
0.83
* Time to first appropriate ICD therapy was compared with the log-rank test
12
P-value
Results: Shock outcomes and appropriate therapy
Age <59 yrs
Age 59-70 yrs
Age ≥70 yrs
Entire population
Inadequate safety margin
Appropriate ICD therapy
n=245
7%
15%
n=260
2%
25%
n=227
2%
26%
<0.01
0.02
Ischemic heart disease
Inadequate safety margin
Appropriate ICD therapy
n=114
3%
14%
n=172
2%
28%
n=170
3%
29%
0.94
<0.01
Nonischemic heart disease
Inadequate safety margin
Appropriate ICD therapy
n=131
12%
16%
n=88
2%
17%
n=57
0%
17%
<0.01
0.83
13
P-value
Conclusions
Inadequate safety margins:
• Entire population: 1-out-of-25
• Nonischemic heart disease: 1-out-of-17
• In young patients: 1-out-of-8
• In the elderly: 1-out-of-100
• In ischemic heart disease the risk was 1-out-of-33
• Irrespective of age
• Age matters in case of nonischemic heart disease
14
Conclusions
Appropriate therapy:
• Entire population: Two year-cumulative incidence of 22%
• Similar risk across the age groups in nonischemic heart disease
• In ischemic heart disease the risk was lower in the young
• In young patients: 14%
• In the elderly: 28-29%
• Age matters in case of ischemic heart disease
15
The Age Paradox in ICD Testing: A
Study on Inadequate Safety Margins
and Long-term Appropriate Therapy
J.L. Bonnes1, S.W. Westra1, E.S. Zegers2, M.A. Brouwer1, J.L.R.M. Smeets1
1 Radboud
2 Canisius
UMC Nijmegen
Wilhelmina Hospital Nijmegen
j.bonnes@cardio.umcn.nl