Download Patients with implantable cardioverter defibrillator shocks: what is

Managing implantable defibrillator shocks
Patients with ICD shocks:
What is the risk?
Frieder Braunschweig MD PhD FESC
Karolinska University Hospital
Stockholm, Sweden
Evolution of ICD therapy
Worldwide ICD implants (estim # per Year)
360 000
MADIT-CRT
300 000
240 000
CRT-D
180 000
120 000
60 000
FDA
First Human
Approval
Implant
0
1980
1985
1990
SCD –HeFT
DualChamber
COMPANION
ICDs
MADIT-II
•Transvenous Leads
MUSTT
•Biphasic Waveform
AVID
CASH
MADIT
CIDS
1995
2000
2005
2010
Patient with ICD shock (s)
New clinical picture
• Increasing incidence
• Symptoms with a broad range of severity
• Other medical conditions may be involved
• Causes psychological distress and anxiety
• Barrier to ICD implantation
Who gets involved?
ICDspecialist
EP
ICD-nurse
-
Pacemaker
Family
technician
practitioner
Patient with
CRT
ICD
shock(s)
Patient
HF nurse/
Ambulance
coordinator
personal
Emergency
medicine
Internist
General
Imaging
specialist
cardiologist
Types of shock
1) Appropriate shocks
- VF, VT
2) Unnecessary shocks
- Haemodynamically tolerated NSVT
- Haemodynamically tolerated VT sensitive for ATP
3) Inappropriate shocks
- Supraventricular tachycardia (AF!)
- Signal misinterpretation (EMG, interference, device failure)
4) Phantom shocks
How common?
Shocks (total)
70
60
(%) 50
appropriate
inappropriate
Annual shock rate appr 10% (appr), 7.5% (inappr)
40
30
20
10
0
AVID
MADIT II
DEFINITE
SCD-HeFT COMPANION PREPARE
1997
2002
2004
2005
2004
2008
n=492
n=719
n=227
n=811
n=594
n=700
24/12M
22M
29M
45M
16M
12M
Secondary
Primary
Primary
Primary
Primary
Primary
ICM + DCM
ICM
DCM
ICM + DCM
ICM + DCM
ICM + DCM
ICD
ICD
ICD
ICD
CRT-D
ICD + CRT-D
(single lead)
Predictors of shock
TOVA study: cohort study, n=1140 ICD, 95% secondary prevention
Whang et al, Circulation. 2004;109:1386-1391
Predictors of appropriate therapy
MADIT II
Probability of first appropriate ICD
therapy for VT or VF
n=720
281 VT terminated by ATP (147 pts)
305 VT terminated by shock (108 pts)
115 VF terminated by shock (36 pts)
Moss et al, Circulation. 2004;110:3760-3765
Predictors of appropriate therapy
MADIT II
Patients receiving 1 or more device therapies
140
139
120
VT therapies
30
VF therapies
25
30
VF therapies
VT therapies
100
20
75
80
18
15
60
48
40
0
1
5
2
4
3
2
4
9
6
21
20
6
10
10
32
6
5
2
5
0
3
1
2
2
3
1
4
First Therapy: VT
First Therapy: VF
54% of repeat episodes occurring within 24 h, 67% within 1 w, 93% within 6 M
Further predictors of electrical therapy:
• Higher NYHA-class
• Interim MI was no predictor
Moss et al, Circulation. 2004;110:3760-3765
1
5
Predictors of inappropriate shocks
Inappropriate shocks over time
(11.5% of pts)
MADIT II
AF (44%)
SVT (36%)
Inappr sensing (20%)
Predictors of inappropriate shock
Daubert et al
JACC 2008;51:1357–65
Risk factors: appropriate therapies
Patient
- Previous ventricular arrhythmia
- Previous myocardial infarction, (ischemia)
- Symptomatic HF
- Inappropriate drug treatment
Betablockers (!), “antiarrhythmics” (?)
- Distress, depression
- Male gender
- Smoking
- Genetic susceptibility
Device
- Inappropriate programming
Detection-rate / –duration, ATP
Risk factors: inappropriate therapies
Patient
- History of AF, other SVT
- Younger age
- Non ischemic cardiomyopathy
- Symptomatic HF
- Inappropriate drug treatment (Betablockers !)
- Distress
- Smoking
Device
- Inappropriate programming
Detection zones, SVT discrimination
- Signal misclassification
- System failure
Risk factors: electrical storm
Definition: 3 or more distinct VT/VF episodes within 24 h
• More common in secondary (10-40%) vs primary prevention
• No apparent cause in majority of cases
• Potential triggering factors:
- Drugs (pro-arrhythmia, non-compliance)
- Worsening HF
- Myocardial ischaemia
- Emotional stress and anger
- Alcohol excess
- Electrolyte abnormalities
- Early postoperative period
Prognosis after ICD therapies
MADIT II (ICD group analysis)
Probability of CHF hospitalization
Probability of
CHF hospitalization
1.0
0.8
0.6
Post VF Therapy
0.4
Post VT Therapy
0.2
Prior to Therapy
p<0.05
0
0
1
2
3
Years
Patients at risk
Post VF therapy 30
Post VT therapy 139
Prior to therapy 718
13 (0.31)
54 (0.26)
344 (0.19)
1 (0.48)
29 (0.29)
165 (0.25)
Moss et al, Circulation. 2004;110:3760-3765
8 (0.36)
53 (0.31)
Prognosis after ICD therapies
MADIT II (ICD group analysis)
Probability of survival
1.0
Prior to Therapy
Survival
0.8
Post VT Therapy
0.6
0.4
Post VF Therapy
0.2
p<0.001
0
0
1
2
3
Years
Patients at risk
Prior to therapy 719
Post VT therapy 139
Post VF therapy 30
419 (0.94)
61 (0.82)
15 (0.80)
206 (0.89)
29 (0.74)
3 (0.49)
Moss et al, Circulation. 2004;110:3760-3765
76 (0.83)
8 (0.74)
1 (0.32)
Prognosis after ICD shock (s)
COMPANION (CRT-D group analysis)
Free from All-cause Mortality (%)
Free from Pump Failure Death and
HF Hospitalization (%)
Saxon et al, Circulation. 2006;114:2766-2772
Prognosis after ICD shock (s)
SCD-HeFT (ICD group analysis)
n=811 (269 pts received shocks: 128 only appr, 87 only inappr, 54 both)
Adjusted for baseline prognostic factors
Death due to progressive HF: 42.9%
Poole JE and al N Engl J Med 2008;359:1009-17
Poor prognosis after shock
Possible explanations
•
Ventricular arrhythmia = harbinger of end stage heart failure
•
Atrial arrhythmia (inappr) = risk marker of heart failure
•
Cellular damage and negative inotropic effects, activation of
signaling pathways in the molecular cascade of HF
•
Post traumatic stress
Vicious circle of stress and arrhythmia
Autonomic imbalance
HR  HRV
Inflammation 
Distress
(Anxiety /
Depression)
Tachyarrhythmia /
shock
Increased perception,
dysfunctional appraisal,
maladaptive coping
Personality
Pre-existing distress
Social support
Vicious circle of stress and arrhythmia
Prognostic Impact of post-traumatic
stress disorder (PTSD)
147 ICD patients, n=38 with a high PTSD score
Ladwig KH et al, Arch Gen Psychiatry. 2008;65(11):1324-1330
Independent prognostic impact of shocks
Sweeney MO, Heart Rhythm 2010;7:353–360
How can the risk be reduced?
Optimizing the management of patients receiving ICD shocks
•
Acute work-up
•
Optimal programming
•
Optimization of medication (arrhythmia, ischemia, heart failure)
•
Ablation of supraventricular and ventricular substrates
•
Diagnosing and treating anxiety and distress
•
Psychosocial support
•
Education of non-electrophysiologists
Europace in press
Task force members: Frieder Braunschweig (chair), Giuseppe Boriani (co-chair)
Alexander Bauer, Robert Hatala, Christoph Herrmann-Lingen, Josef Kautzner,
Susanne S Pedersen, Steen Pehrson, Renato Ricci, Martin Schalij
Summary
ICD patients frequently suffer from appropriate, unnecessary
and inappropriate shocks.
The individual risk is modulated by a number of characteristics
including the secondary or primary indication for the device,
degree of LV impairment, heart failure etiology and severity
and other factors.
Summary II
The burden of ICD-shock patients is increasing due to
increasing implantation rates.
Fortunately, modern empiric programming of ATP and
detection algorithms results in a marked reduction of the
individual risk of suffering from shocks.
However, appropriate and possibly even inappropriate ICD
shocks are associated with an increased risk for repeat
arrhythmia and shocks, deteriorated heart failure and death.
Therefore a comprehensive management strategy with the aim
to reduce the number of shocks is mandatory.
Electrical storm
Risk of shock: primary vs secondary
PainFREE Rx II
Patients (n)
Pts shocked
Appropriate
Inappropriate:
Primary Prevention
248
20 %
11 %
9%
Secondary Prevention
334
23 %
15 %
9%
Sweeney et al, Circulation. 2005; 111:2898-2905
ns
ns
ns
ns
Appropriate vs unneccessary shocks
Number of episodes
140
VF
10%
120
100
VT
58%
73% amenable
to ATP
FVT
32%
80
60
40
20
0
<200 200 220 240 260 280 300 320 340 360 380 400 420 440 >460
Median Cycle Length (ms)
Wathen et al Circulation. 2004;110:2591-2596