Transcript ICD FOR PRIMARY PREVENTION

DR SANDEEP.R
SR CARDIO
1

The implantable cardioverter defibrillator (ICD) is a
battery-powered implantable device that can detect and
terminate potentially life-threatening tachyarrhythmias
via defibrillation or antitachycardia pacing to prevent
SCD

Sudden cardiac death (SCD) remains the leading cause
of death
ICD has been recommended for secondary prevention
of sudden cardiac death based on several RCT

2

But only a small percentage of patients who suffer
cardiac arrest survive to benefit from the ICD
therapy as secondary prevention

Thus prophylactic use of ICD for primary prevention
of SCD becomes an attractive option for high-risk
patients
3
 ICD
IN ISCHAEMIC CARDIOMYOPATHY
4
32 hospital centers (30 in the United States and 2 in Europe)
Study period 1990-1995
(N Engl J Med1996;335:1933-40.)
5
INCLUSION CRITERIA
EXCLUSION CRITERIA
NYHA I, II, or III with prior M.I
Previous cardiac arrest or VT causing
syncope that was not associated with
AMI
LVEF < 0.35
Acute Myocardial infarction < 3 weeks
Documented episode of
asymptomatic unsustained VT
Patients who underwent CABG within
the past two months or PTCA within the
past three months
Inducible, nonsuppressible VT
on EP study
Symptomatic hypotension while in a
stable rhythm
Had no CABG /PTCA in last 3
mths
6
•N=196
•Two patient groups (1:1)
randomization
1. Conventional Medical Therapy
(CMT)
2.ICD
•Mean follow up 27 months
•Primary endpoint: All cause Mortality
7
•CONCLUSION
•54% reduction in all cause mortality in ICD group
•No evidence for of mortality benefit with amiodarone ,betablockers
10
•The trial was conducted at 37 clinical centers, 35 in the US & 2 in Germany
•Study period – 1992-98
•900 patients who came for elective CABG were
randomized into ICD ( 446) VS no ICD group ( 454)
•The primary endpoint was all-cause mortality
INCLUSION CRITERIA
< 80 yrs age
LVEF< 0.36
Abnormalities on a signalaveraged
electrocardiogram
11
CONCLUSION
•No evidence of improved survival among
patients with coronary heart disease, a
depressed LVEF , and an abnormal signalaveraged ECG in whom a defibrillator was
implanted prophylactically at the time of
elective CABG
12

The trial was designed to study the concept of guiding the management of high
risk patients with the results of EPS

Not primarily designed as a randomized ICD clinical trial
AIM: To evaluate the efficacy of antiarrhythmic therapy guided by EP
testing in reducing the risk of SCD and cardiac arrest among patients
with CAD, LV dysfunction, and asymptomatic, unsustained VT

STUDY PERIOD-1991-1997 & median follow-up of 39 months
Buxton AE. N Engl J Med 1999;341:1882-90
13
INCLUSION CRITERIA
EXCLUSION CRITERIA
Patients with CAD
H/O
syncope/sustained
VT/VF > 48hrs of MI
LVEF<40%
NSVT due to
metabolic causes
Asymptomatic, unsustained VT
Symptomatic,
unsustained VT
Patients in whom sustained VT
were induced by programmed
stimulation
14
Primary Endpoint
Arrhythmic death or cardiac arrest
Secondary Endpoints
Total mortality
Cardiac mortality
Spontaneous, sustained VT
15
MUSTT EP-Guided Rx Patients
Treatment at Discharge
No Rx
IA
7%
26%
Sotalol
9%
ICD
Amiodarone
46%
10%
Buxton AE. N Engl J Med 1999;341:1882-90.
Antiarrhythmic
Drugs: 45%
No EP-Guided AA Rx
EP-Guided Rx, (No ICD and ICD)
0.5
Event Rate
0.4
p = 0.04
0.3
0.2
0.1
0
0
1
2
3
Time after Enrollment (Years)
Buxton AE. N Engl J Med 1999;341:1882-90.
4
5
19

The two-year (12 versus 18 percent) and five-year (25 versus 32 percent)
rates for the primary endpoint were significantly lower for EPS guided
therapy compared to no therapy

There was a nearly significant reduction in the secondary endpoint of
total mortality at five years in the group receiving EPS guided therapy
(42 versus 48 percent, p = 0.06).

The reduction in the primary and secondary endpoints in the EPS guided
group was largely attributable to ICD therapy

At five years the primary endpoint occurred in 9 percent of those
receiving an ICD compared with 37 percent of those receiving an
antiarrhythmic drug, and the secondary endpoint occurred in 24 and 55
percent respectively.

There was no difference in outcome between patients receiving no
therapy and those treated with an antiarrhythmic drug
20
Electrophysiologically
guided antiarrhythmic therapy with
implantable defibrillators but not with antiarrhythmic drugs
reduces the risk of sudden death in high-risk patients with
coronary disease
At
5 years, there were absolute reductions in total
mortality of 31% in the patients receiving ICD therapy when
compared with those receiving pharmacological therapy and
of 24% when compared with those receiving no therapy
21
EXCLUSION
INCLUSION
AIM:
To evaluate the potential
survival benefit of a prophylactically implanted
M.I >4 WEEKS
Revascularization within the preceding three months
defibrillator (in the absence of electrophysiological testing to induce
arrhythmias)
in patients with aM.Iprior
M.I and LVEF< 0.30
LVEF <30%
< 3 weeks
New York Heart Association
Enrolled patients from 76 hospital
centers
and 5 in Europe)
functional
class (71
IV atUS
enrollment
STUDY PERIOD 1997-2001
PRIMARY OUTCOME ALL CAUSE MORTALITY
N Engl J Med, Vol. 346, No. 12
22
1232 Patients with prior MI more than 30 days and LVEF < 30% randomized in
a 3:2 ratio
Implantable defibrillator
Conventional medical
therapy
(n=742)
(n=490)
All Cause Mortality - Average follow-up of 20 months
Stopped early
23
25
Death
25%
20%
Avg. follow-up=20 months
P=0.016
19.8%
Hazard
Ratio = 0.65
14.2%
15%
10%
5%
0%
Conventional
Therapy
ICD
Non Cardiac
15%
Cardiac
Arrhythmic
Non Arrhythmic
13.7%
10.0%
10%
9.4%
5.5%
5%
0%
4.1%
3.6%
3.5%
Conv ICD
Therapy
Conv ICD
Therapy
Conv ICD
Therapy
3.7%
Conv ICD
Therapy
New or Worsening Heart Failure
P=0.09
20%
15%
19.9%
14.9%
10%
5%
0%
Conventional
Therapy
ICD
INTERESTING FACTS:







In the current study the survival benefit began approximately
nine months after the device was implanted
No ep study used
Increased incidence of heart failure in ICD group
REASONS FOR HEART FAILURE
1. INCREASED SURVIVAL
2.SHOCK INDUCED MYOCARDIAL INJURY
3.LONG TERM PACING INDUCED DYSFUNCTION
CONCLUSION
› In patients with a prior myocardial infarction and
advanced left ventricular dysfunction, prophylactic
implantation of a defibrillator improves survival and should
be considered as a recommended therapy

Study period 1997-2001
INCLUSION CRITERIA
Patients >18 years of age

The primary end point of the trial was death
from any cause

N=2521

The etiology of cardiomyopathy was
ischemic in 52 percent and nonischemic in
48 percent
NYHA class II or III
Stable CHF due to
ischemic or non ischemic
causes & LVEF < 35
percent
30
Inclusion criteria
Placebo n=847
Amiodarone n=845
ICD implant n=829
40 months average follow- up
• Optimize: B, ACE-I, Diuretics
Bardy GH. Chapter Excerpt from Arrhythmia Treatment and Therapy. Woosley RL, Singh SN, editors. Marcel
Dekker, 1st edition. 2000;323-42.
1
32
33
34

In NYHA Class II or III HF patients with EF < 35% on good
background therapy, the mortality rate for placebo-controlled
patients is 7.2% per year over 5 years

Simple, shock-only ICDs decrease mortality by 23% (p=0.007) &
the benefit did not vary according to the cause of CHF

Amiodarone, when used as a primary preventative agent, does
not improve survival
DINAMIT
 IRIS

36
Evaluated the role of prophylactic ICD implantation
compared to no ICD
Inclusion criteria
 674 patients with MI in the preceding 6 to 40 days (mean
18 days)
 LVEF ≤35 percent
 Reduced heart rate variability or elevated resting heart
rate (≥80beats/min).
Exclusion criteria
 Patients with sustained VT >48 hours post-MI, NYHA class IV
HF, or coronary artery bypass grafting (CABG) or threevessel percutaneous coronary intervention post-MI
 Mean follow-up was 30 months.
NEJM 2004:351:2481-8
37
38
39
40

Enrolled 898 patients
Inclusion criteria:
 MI within the preceding 5 to 31 days and one or both of
the following two criteria:
 LVEF ≤40 percent and a resting HR ≥90 beats/min
 Nonsustained VT at a rate ≥150 beats/min
Mean follow-up - 37 months
41
•RESULTS:
•No difference in all-cause mortality
between patients randomly assigned to
ICD therapy VS medical therapy.
•The rate of SCD higher in the control
group
•The number of non sudden cardiac
deaths higher in the ICD arm
42

Significant recovery of ventricular function may have
occurred in some of the patients which would dilute the
long-term benefit of the ICD in such patients.

Some SCD events in the early postinfarction period may
have been due to recurrent ischemia which would not be
definitively treated by ICD discharge

ICD implantation might impose additional risk in these
patients immediately post-MI.

The enrollment requirements of reduced heart rate
variability in DINAMIT and resting heart rate ≥90 beats/min
in IRIS could have selected a group of patients with a high
mortality from nonarrhythmic causes .
43
44
ICD IN NONISCHAEMIC CMPY
45
INCLUSION CRITERIA
•LVEF < 36%
•Nonischemic DCMPY
•PVCs or NSVT
N=458
RANDOMIZATION
N=229
standard medical
therapy + ICD
N=229
standard
medical therapy
STUDY PERIOD – 1998-2002
•The primary end point
of the study was death
from any cause
•Sudden death from
arrhythmia was a prespecified secondary
end point
EXCLUSION CRITERIA
•NYHA CLASS IV
•THOSE WITH PPI
•HEART TRANSPLANT ELIGIBLE
N Engl J Med 2004;350:2151-8.
46
HR for death from any cause was 0.65
(95% C.I 0.40 to 1.06)
HR for sudden death from arrhythmia was
0.20 (95 % C.I 0.06 to 0.71)
47
48
49
50
ICD COMBINED WITH CRT
51

1520 patients




NYHA class III-IV HF
LVEF ≤35 percent
Lbbb > 120 msec
Nearly half of all patients enrolled had a nonischemic etiology of HF.
Randomly assigned to optimal medical therapy, CRT alone, or CRT+ICD
The primary end point was a composite of death from any cause or
hospitalization for any cause
Secondary end point - death from any cause
NEJM 350:21 MAY 2004
52
53
54
CRT+ICD
, as compared with optimal pharmacologic
therapy, was associated with a 27% reduction in the risk of
death from any cause in the subgroup with ischemic CMPY
(HR for death, 0.73; 95% C.I, 0.52 to 1.04) & a 50
%reduction in nonischemic CMPY
CONCLUSION

Patients with advanced heart failure and a prolonged QRS
interval, CRT decreases the combined risk of death from any
cause or first hospitalization and, when combined with an
ICD, significantly reduces mortality
55
EPS
MADITMADIT
II
MUSTT
SCD-HeFT
COMPANION
LVEF
QRS≥12
0
PVC
NSVT
DEFINITE
LVEF
SCD-HeFT
COMPANION
QRS≥120
THANK YOU
63