SCD and Misc : Cardiology

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SCD and Misc : Cardiology

ICD

Subcutaneous

Not used if patient has a current or future indication for pacing
Transvenous is better for monomorphic VT

Transvenous

RV coil (anode +)
SVC coil (cathode -)

Note: generator is also cathode -

ICDs handle VT and VF differently
Question:

How does device differentiate between SVT and VT?

Answer: By looking into following features

Onset
Stability
Morphology
V-A Relationship

Cardiac Sarcoid
HC

Note: Remote monitoring actually helps in mortality benefit

Likely mechanism:

Early detection of A fib
Early detection of mis-firing or appropriate firing, and bringing these patients identifying the cause and timely optimization of medical therapy may be the reason for improve survival advantage

Note: Shocks themselves are associated with poor longterm outcome. So, we have to avoid any unnecessary shocks.

Pacemaker and ICD sense differently

Understanding how each sense the abnormality is the key in understanding pacemaker or ICD

Primary prevention of SCD after MI

Late Post-MI Trials

MADIT (1996)

Prior MI
NSVT on monitoring
LVEF (≤35 percent)
Inducible sustained monomorphic VT during electrophysiology study (EPS) that was also inducible after administration of intravenous procainamide

MUSTT (1999)

Prior MI (4 days post MI to 3 yrs prior)
Asymptomatic NSVT (at least 4 days post MI )
EF < 40
Inducible Sustained VT during EPS in a patient with NSVT
No history of Sustained VT or V tach (Secondary prevention)

MADIT2 (2002)

Prior MI (>30 days of MI or > 3 months of CABG
EF <30

CABG Patch Trial (1997 NEJM)

Severe CAD requiring surgical revascularization
LVEF <36 percent
Abnormal signal-averaged electrocardiogram
No history of sustained ventricular tachyarrhythmia or syncope

SCD HeFT (2005 NEJM)

> 40 days post MI
NYHA II-III,
EF < 35
CHF present for at least 3 mth prior to randomization with optimal medical management

Bottom line

SCE HeFT criteria (No need to fulfill other electrical criteria of MADIT-I due to its absence in SCD HeFT and still had benefit)
MUSTT Trial Data still valid due to EF < 40 % as inclusion criteria

Vs. SCD HeFT: less severe patients but high risk on further Elecrophysiological Study

MADIT - II still valid as it was for EF < 30 % and NYHA Class I patients

Vs. SCD HeFT: Less symptoms but higher risk by EF

Early POST-MI

DYNAMIT
IRIS

Non-ischemic Cardiomyopathy

SCDHeFT (had both patient population) Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT)

Amiodarone or an Implantable Cardioverter–Defibrillator for Congestive Heart Failure
2521 patients, half of whom had nonischemic systolic heart failure.
The only randomized trial involving patients with nonischemic systolic heart failure in which a significant benefit with regard to all-cause mortality
In patients with NYHA class II or III CHF and LVEF of 35 percent or less, amiodarone has no favorable effect on survival, whereas single-lead, shock-only ICD therapy reduces overall mortality by 23 percent.
However, the positive effect of ICD treatment was confined to patients in NYHA class II, and no patients received concomitant CRT. In addition, medical treatment for heart failure has changed since SCD-HeFT was conducted. Only 69% of enrolled patients received beta-blockers at baseline, 20% of patients received a mineralocorticoid-receptor antagonist, and no patients received concomitant CRT
enrolled patients between 1997 and 2001, and

The Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION) study

1520 patients
New York Heart Association (NYHA) class III or IV heart failure
medical therapy, a cardiac re- synchronization therapy (CRT) pacemaker, or a CRT defibrillator,
significantly lower all-cause mortality in association with a CRT defibrillator than with medical treatment alone, but a CRT defibrillator was not shown to be superior to a CRT pacemaker
http://www.nejm.org/doi/pdf/10.1056/NEJMoa1608029

The Cardiomyopathy Trial (CAT)

2002
Primary Prevention of Sudden Cardiac Death in Idiopathic Dilated Cardiomyopathy
This trial did not provide evidence in favor of prophylactic ICD implantation in patients with DCM of recent onset and impaired left ventricular ejection fraction.
Patients were eligible if they were between 18 and 70 years of age, had symptomatic DCM for ≤9 months and impaired LV function (LVEF ≤30% obtained during LV angiography), and were in NYHA class II or III. Coronary artery disease (coronary stenosis >70%) had to be excluded by angiography. Patients with a history of prior myocardial infarction, myocarditis, or excessive alcohol consumption were not included in the trial
https://sites.google.com/a/imreference.com/main/cardiology/misc-cardiology?pli=1

AMIOVIRT

Amiodarone versus implantable cardioverter-defibrillator:randomized trial in patients with nonischemicdilated cardiomyopathy and asymptomatic non sustained ventricular tachycardia
Mortality and quality of life in patients with NIDCM and NSVT treated with amiodarone or an ICD are not statistically different. There is a trend towards a more beneficial cost profile and improved arrhythmia-free survival with amiodarone therapy
JACC 2003

DEFINITE

enrolled patients between 1998 and 2002,
included a larger proportion of patients who received beta-blockers (85%) but, again, no patients who received CRT

DANISH Investigators (NEJM 2016)

A non-ischemic cause of heart failure was usually determined by coronary angiography, although a normal computed tomographic (CT) angiogram or nuclear myocardial perfusion imaging study was acceptable

DANISH (NEJM 2016)

http://www.nejm.org/doi/suppl/10.1056/NEJMoa1608029/suppl_file/nejmoa1608029_appendix.pdf

Secondary Prevention of SCD

AVID (1997)

EF < 40

CASH (2000)
CIDS (2000)

Patient with Remote MI

AVID: Secondary Prevention

AVID NEJM 1997

SCD

Slide on incidence of SCD population and patient studied by primary prevention RCT
Usually STEMI is not seen in normal ECHO
Polymorphic VT are mostly ischemic
Paper