Download Electrical Risk Stratification After STEMI

Electrical Risk Stratification
After STEMI
Peter Cheung, MD, FACC
Section of Electrophysiology,
Division of Cardiology,
Scott & White Clinic
Texas A&M Health Science Center
Liew, Heart 2010; 96: 1086-94
Define Electrical Risk Stratification
• I. Whether patient has a ventricular
arrhythmia that is a marker for increased risk
of sudden cardiac death (SCD).
• II. Whether there is any electrocardiographic
risk stratification scheme for a patient with
low EF.
Electrical Risk Stratification
• For all practical purposes, risk stratification is
same whether it is STEMI or NSTEMI.
• Risk stratification for patient without CAD is
outside the scope of this talk.
Epidemiology of VA & SCD
Incidence of Sudden Cardiac Death
Events
Incidence
General
population
High-risk
subgroups
Any prior
coronary event
EF<30% or
heart failure
MADIT II
Cardiac arrest
survivor
AVID, CIDS, CASH
Arrhythmia risk
markers, post MI
MADIT I, MUSTT
0
10
20
Percent
30
Myerburg RJ, Kessler KM, Castellanos A. Circulation 1992;85:12-10.
0
150,0000
SCD--HeFT
300,000
Absolute Number
Why do we even ask?
Major Implantable Cardioverter-Defibrillator Trials for
Prevention of Sudden Cardiac Death
Trial
Year
Patients
(n)
Inclusion
Criterion:
LVEF
Additional Study
Features
Hazard
Ratio*
95% CI
p
MADIT I
1996
196
< 35%
NSVT and EP+
0.46
(0.26-0.82)
p=0.009
MADIT II
2002
1232
< 30%
Prior MI
0.69
(0.51-0.93)
p=0.016
CABG-Patch
1997
900
< 36%
+SAECG and CABG
1.07
(0.81-1.42)
p=0.64
DEFINITE
2004
485
< 36%
NICM, PVCs or NSVT
0.65
(0.40-1.06)
p=0.08
DINAMIT
2004
674
< 35%
6-40 days post-MI
and Impaired HRV
1.08
(0.76-1.55)
p=0.66
SCD-HeFT
2006
1676
< 35%
Prior MI or NICM
0.77
(0.62-0.96)
p=0.007
AVID
1997
1016
< 40%
Prior cardiac Arrest, or
Unstable VT
0.62
(0.43-0.82)
p<0.02
CASH†
2000
191
Mean < 45%
±18 at baseline
Prior cardiac arrest
0.766
‡
1-sided
p=0.081
CIDS
2000
659
< 35%
Prior cardiac Arrest,
Unstable VT, or Syncope
0.82
(0.60-1.1)
NS
* Hazard ratios for death from any cause in the ICD group compared with the non-ICD group. Includes only ICD and amiodarone patients from CASH.
‡CI Upper Bound 1.112. CI indicates Confidence Interval, EP+ = positive electrophysiologic study, HRV = heart rate variability, LVEF = left ventricular ejection fraction,
MI = myocardial infarction, NICM = nonischemic cardiomyopathy, NS = Not statistically significant, NSVT = nonsustained ventricular tachycardia, PVCs = premature
ventricular contractions, SAECG = signal-averaged electrocardiogram, VT = ventricular tachycardia.
Epstein A, et al. ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities. J Am Coll Cardiol 2008; 51:e1–62. Table 5.
DiMarco. NEJM 2003; 349:1836-1847
Drugs don’t prevent SCD
• Antiarrhythmic Drugs worse than Placebo
– CAST (Cardiac Arrhythmia Suppression Trial)
– MUSTT (Multicenter Unsustained Tachycardia Trial)
• ICD better than Antiarrhythmic Drugs
–
–
–
–
AVID (Antiarrhythmic versus Implantable Defibrillators)
CIDS (Canadian Implantable Defibrillator Study)
CASH (Cardiac Arrest Study Hamburg)
SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial)
• Amiodarone no better than Placebo
– SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial)
CAST
CAST Investigators, Aug 1989, NEJM
SCD-HeFT
Problems with ICD
• Very expensive
• Complications of infection, vascular injuries,
inappropriate ICD shocks
Why Electrical Risk Stratification?
• Identify patients that you can do something
about- ICD
• Avoid overtreating
– Expensive
– Complications associated with ICD
• Unfortunately, electrical risk stratification is
more or less an academic exercise
Electrical Risk Stratification
• I. Whether patient has a ventricular
arrhythmia that is a marker for increased risk
of sudden cardiac death (SCD).
• II. Whether there is any electrocardiographic
risk stratification scheme for patient with low
EF.
What type of electrical risk marker? (>
48 hours post-MI)
• PVC’s (CAST)
• NSVT & (+) EP Study (MADIT, MUSTT)
• VT/VF (AVID, CIDS, CASH)
What type of electrical risk marker?
(> 48 hours post-MI)
• PVC’s (CAST)
• NSVT & (+) EP Study (MADIT, MUSTT)
• VT/VF (AVID, CIDS, CASH)
.
Pratt C M , Moyé L A Circulation 1995;91:245-247
Copyright © American Heart Association
What type of electrical risk marker?
(> 48 hours post-MI)
• PVC’s (CAST)
• NSVT & (+) EP Study (MADIT, MUSTT)
• VT/VF (AVID, CIDS, CASH)
NSVT & (+) EP Study
• MADIT (Multicenter Automatic Defibrillator
Implantation Trial)- prior MI (> 3wk), NSVT (>
120bpm), EF ≤ 35%, no revascularization in 3
months
• MUSTT (Multicenter Unsustained Tachycardia
Trial)- CAD, LVEF ≤ 40%, NSVT, +EPS
Multicenter Unsustained
Tachycardia Trial- MUSTT
• CAD, LVEF ≤ 40%, NSVT, +EPS
• No statistically significant difference in the
frequency or duration of spontaneous
nonsustained ventricular tachycardia was seen
between patients with and those without
inducible sustained ventricular tachycardia.
What type of electrical risk marker?
(> 48 hours post-MI)
• PVC’s (CAST)
• NSVT & (+) EP Study (MADIT, MUSTT)
• VT/VF (AVID, CIDS, CASH)
Major Implantable Cardioverter-Defibrillator Trials for
Prevention of Sudden Cardiac Death
Trial
Year
Patients
(n)
Inclusion
Criterion:
LVEF
Additional Study
Features
Hazard
Ratio*
95% CI
p
MADIT I
1996
196
< 35%
NSVT and EP+
0.46
(0.26-0.82)
p=0.009
MADIT II
2002
1232
< 30%
Prior MI
0.69
(0.51-0.93)
p=0.016
CABG-Patch
1997
900
< 36%
+SAECG and CABG
1.07
(0.81-1.42)
p=0.64
DEFINITE
2004
485
< 36%
NICM, PVCs or NSVT
0.65
(0.40-1.06)
p=0.08
DINAMIT
2004
674
< 35%
6-40 days post-MI
and Impaired HRV
1.08
(0.76-1.55)
p=0.66
SCD-HeFT
2006
1676
< 35%
Prior MI or NICM
0.77
(0.62-0.96)
p=0.007
AVID
1997
1016
< 40%
Prior cardiac Arrest, or
Unstable VT
0.62
(0.43-0.82)
p<0.02
CASH†
2000
191
Mean < 45%
±18 at baseline
Prior cardiac arrest
0.766
‡
1-sided
p=0.081
CIDS
2000
659
< 35%
Prior cardiac Arrest,
Unstable VT, or Syncope
0.82
(0.60-1.1)
NS
* Hazard ratios for death from any cause in the ICD group compared with the non-ICD group. Includes only ICD and amiodarone patients from CASH.
‡CI Upper Bound 1.112. CI indicates Confidence Interval, EP+ = positive electrophysiologic study, HRV = heart rate variability, LVEF = left ventricular ejection fraction,
MI = myocardial infarction, NICM = nonischemic cardiomyopathy, NS = Not statistically significant, NSVT = nonsustained ventricular tachycardia, PVCs = premature
ventricular contractions, SAECG = signal-averaged electrocardiogram, VT = ventricular tachycardia.
Epstein A, et al. ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities. J Am Coll Cardiol 2008; 51:e1–62. Table 5.
Electrical Risk Stratification
• I. Whether patient has a ventricular
arrhythmia that is a marker for increased risk
of sudden cardiac death (SCD).
• II. Whether there is any electrocardiographic
risk stratification scheme for patient with low
EF.
EKG risk markers ?
•
•
•
•
QRS duration- conflicting data
Fragmented QRS- undetermined
QT dispersion- undetermined
Early repolarization- undetermined
Risk Stratification Tests
•
•
•
•
•
Signal Average ECG
Holter
T wave alternan
Electrophysiology Study
None
Signal-Averaged ECG
•
•
•
•
•
Ventricular Late Potentials (VLPs)
Potential substrate to ventricular arrhythmia
Seen in 25-50% after AMI
Sensitivity 15-75%
Prognostic value seems much diminished in
patients who underwent revascularization.
Conventional Holter
• PVCs
• NSVT
• Low sensitivity and specificity
Heart rate variability
•
•
•
•
SD of RR intervals
Measures of cardiac autonomic tone
HRV decreases with AMI
Decreased HRV associated with increased
mortality- Multicenter Postinfarction Study
(MPS)
• Revascularization seems to improve HRV
Heart Rate Turbulence
• Fluctuations in sinus rhythm following PVC
• REFINE Study (Noninvasive Risk Assessment
Early After a Myocardial Infarction)- (+) Study
especially performing at 10-14 weeks.
• ISAR-Risk Study (Improved Stratification of
Autonomic Regulation for risk prediction in
post-infarction patients with preserved left
ventricular function)- (+)
Microvolt T-Wave Alternans
(MTWA)
MASTER (Microvolt T Wave Alternans Testing
for Risk Stratification of Post-Myocardial
Infarction Patients) Trial- CAD, EF < 30%, (-)
patients have less event.
ABCD (Alternans Before Cardioverter
Defibrillator) Trial- 1 year PPV 9%, NPV 95%.
Patients not immediately post-MI.
Whether revascularization may affect MTWA
is not studied.
EP Study
• MADIT (Multicenter Automatic Defibrillator
Implantation Trial)- prior MI (> 3wk), NSVT (>
120bpm), EF ≤ 35%, no revascularization in 3
months
• MUSTT (Multicenter Unsustained Tachycardia
Trial)
What clinical roles do electrical risk
stratification play?
• Not much.
• Noninvasive electrophysological testing may
be helpful but guidelines do not support ICD
use based on it.
• Guidelines support invasive EP study to risk
stratify patients with NSVT and EF between
35-40%.
• Guidelines support risk stratification by nonelectrophysiological means.
Dichotomy of Approach
• Most clinical trials trend toward broader use
of ICD
– AVID- history of SCD
– MADIT 1- NSVT, + EPS, EF ≤ 35%
– MUSTT- NSVT, + EPS, EF ≤ 40%
– MADIT 2- EF ≤ 30%
– SCD-HeFT- EF ≤ 35%
• Electrical Risk Stratification means selective
(reduced) use of ICD
Major Implantable Cardioverter-Defibrillator Trials for
Prevention of Sudden Cardiac Death
Trial
Year
Patients
(n)
Inclusion
Criterion:
LVEF
Additional Study
Features
Hazard
Ratio*
95% CI
p
MADIT I
1996
196
< 35%
NSVT and EP+
0.46
(0.26-0.82)
p=0.009
MADIT II
2002
1232
< 30%
Prior MI
0.69
(0.51-0.93)
p=0.016
CABG-Patch
1997
900
< 36%
+SAECG and CABG
1.07
(0.81-1.42)
p=0.64
DEFINITE
2004
485
< 36%
NICM, PVCs or NSVT
0.65
(0.40-1.06)
p=0.08
DINAMIT
2004
674
< 35%
6-40 days post-MI
and Impaired HRV
1.08
(0.76-1.55)
p=0.66
SCD-HeFT
2006
1676
< 35%
Prior MI or NICM
0.77
(0.62-0.96)
p=0.007
AVID
1997
1016
< 40%
Prior cardiac Arrest, or
Unstable VT
0.62
(0.43-0.82)
p<0.02
CASH†
2000
191
Mean < 45%
±18 at baseline
Prior cardiac arrest
0.766
‡
1-sided
p=0.081
CIDS
2000
659
< 35%
Prior cardiac Arrest,
Unstable VT, or Syncope
0.82
(0.60-1.1)
NS
* Hazard ratios for death from any cause in the ICD group compared with the non-ICD group. Includes only ICD and amiodarone patients from CASH.
‡CI Upper Bound 1.112. CI indicates Confidence Interval, EP+ = positive electrophysiologic study, HRV = heart rate variability, LVEF = left ventricular ejection fraction,
MI = myocardial infarction, NICM = nonischemic cardiomyopathy, NS = Not statistically significant, NSVT = nonsustained ventricular tachycardia, PVCs = premature
ventricular contractions, SAECG = signal-averaged electrocardiogram, VT = ventricular tachycardia.
Epstein A, et al. ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities. J Am Coll Cardiol 2008; 51:e1–62. Table 5.
Epidemiology of VA & SCD
Incidence of Sudden Cardiac Death
Events
Incidence
General
population
High-risk
subgroups
Any prior
coronary event
EF<30% or
heart failure
MADIT II
Cardiac arrest
survivor
AVID, CIDS, CASH
Arrhythmia risk
markers, post MI
MADIT I, MUSTT
0
10
20
Percent
30
0
150,0000
SCD--HeFT
300,000
Absolute Number
Reused with permission from Myerburg RJ, Kessler KM, Castellanos A. Circulation 1992;85:12-10.
ICD
I IIa IIb
IIbIII
III
I IIa IIb III
“is indicated in patients who are survivors of cardiac arrest due
to VF or hemodynamically unstable sustained VT after
evaluation to define the cause of the event and to exclude any
completely reversible causes.”
“is indicated in patients with structural heart disease and
spontaneous sustained VT, whether hemodynamically stable or
unstable.”
I IIa IIb III
“is indicated in patients with syncope of undetermined origin
with clinically relevant, hemodynamically significant sustained
VT or VF induced at EP study. “
All primary SCD prevention ICD recommendations apply only to patients who are receiving optimal medical therapy and have reasonable expectation of
survival with good functional capacity for more than 1 year.
ICD
I IIa IIb
IIbIII
III
“is indicated in patients with LVEF ≤ 35% due to prior MI who
are at least 40 days post-MI and are in NYHA functional Class II
or III.”
I IIa IIb III
I IIa IIb
IIbIII
III
I IIa IIb III
“is indicated in patients with nonischemic DCM who have an
LVEF ≤ 35% and who are in NYHA functional Class II or III.”
“is indicated in patients with LV dysfunction due to prior MI who
are at least 40 days post-MI, have an LVEF ≤ 30%, and are in
NYHA functional Class I.”
“is indicated in patients with nonsustained VT due to prior MI,
LVEF ≤ 40%, and inducible VF or sustained VT at EP study. “
All primary SCD prevention ICD recommendations apply only to patients who are receiving optimal medical therapy and have reasonable expectation of
survival with good functional capacity for more than 1 year.
ICD
I IIaIIbIII
ICD implantation is reasonable for patients with unexplained syncope,
significant LV dysfunction, and nonischemic DCM.
I IIaIIbIII
I IIaIIbIII
ICD implantation is reasonable for patients with sustained VT and normal
or near-normal ventricular function.
ICD implantation is reasonable for patients with HCM who have 1 or
more major† risk factors for SCD.
I IIaIIbIII ICD implantation is reasonable for the prevention of SCD in patients with
arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C)
who have 1 or more risk factors for SCD.
I IIaIIbIII ICD implantation is reasonable to reduce SCD in patients with long-QT
syndrome who are experiencing syncope and/or VT while receiving beta
blockers.
All primary SCD prevention ICD recommendations apply only to patients who are receiving optimal medical therapy and have reasonable expectation of
survival with good functional capacity for more than 1 year.
† See Section 3.2.4, “Hypertrophic Cardiomyopathy,” in the full-text guidelines for definition of major risk factors.
Defibrillator in Acute Myocardial Infarction
(DINAMIT) Trial
• 674 patients < 40 days post-MI with LVEF ≤ 35% and
decreased heart rate variability
• Randomized to ICD therapy (n=332) or no ICD therapy
(n=342)
• Arrhythmic death ↓ in ICD group, but ↑ in nonarrhythmic
death (6.1% per year vs. 3.5% per year, HR 1.75 (95% CI 1.11
to 2.76; p=0.016)
• No difference in total mortality
Hohnloser SH, Kuck KH, Dorian P, et al. Prophylactic use of an implantable cardioverter-defibrillator after acute myocardial
infarction. N Engl J Med 2004;351:2481-8.
MI < 40days, EF ≤ 35%, decreased heart rate variability
Hohnloser SH, Kuck KH, Dorian P, et al. Prophylactic use of an implantable cardioverter-defibrillator after acute myocardial
infarction. N Engl J Med 2004;351:2481-8.
Hohnloser SH, Kuck KH, Dorian P, et al. Prophylactic use of an implantable cardioverter-defibrillator after acute myocardial
infarction. N Engl J Med 2004;351:2481-8.
Defibrillator Implantation Early After
Myocardial Infarction (IRIS)
MI < 40days, EF ≤ 40% (± NSVT)
NEJM 2009: 361:1427-36
IRIS
NEJM 2009: 361:1427-36
Summary
• With the exception of EP Study, current guidelines
neglect use of electrophysiological stratification and
relies mostly on EF and NYHA.
• Some non-invasive electrophysiological tests may
identify patients who are at lower risk of SCD.
Further studies are needed.
• Revascularization may reverse some
electrophysiological risk markers.
• Beware of risk stratification too early after
myocardial infarction. Intervention too early after an
MI does not seem to be beneficial.
Suggested Reading
 Liew, R. Prediction of sudden arrhythmic death
following acute myocardial infarction. Heart
2010; 96:1086-1094.
 ACC/AHA/ESC 2006 Executive Summary.
Guidelines for Management of Patients with
Ventricular Arrhythmias and the Prevention of
Sudden Cardiac Death.
 ACC/AHA/HRS 2008 Executive Summary.
Guidelines for Device-Based Therapy of Cardiac
Rhythm Abnormalities.