EP Show – Aug 2003 ICDs – Primary prevention The EP Show: Which ICD for which patient? Part 2: Primary prevention Eric Prystowsky MD Director, Clinical

EP Show – Aug 2003

ICDs – Primary prevention

The EP Show: Which ICD for which patient? Part 2: Primary preventionEric Prystowsky MD

Director, Clinical Electrophysiology Laboratory St Vincent Hospital

Indianapolis, IN

Helmut Klein MD Head of Division of CardiologyOtto-von-Guericke Universität MagdeburgMagdeburg, Germany

Paul Dorian MD Professor of MedicineDivision of cardiologySt Michael's HospitalToronto, ON



Major trials

Primary prevention patients

MUSTT:• CAD • EF <40%

MADIT I: • CAD • EF <35%

MADIT II:• CAD • EF <30%



Control

ICD

ICD benefit

0

10

20

30

40

MADIT II

2-y

ear

all-c

au

se m

ort

ality

(%

)

31%

MUSTT MADIT I

54%51%

Relative reduction



• EF <40% • CAD • Spontaneous nonsustained ventricular tachycardia (VT-NS)

MUSTT

ICDs (n=161)

Drug therapy (n=153)

p

24% 55% <0.001

Buxton et al. N Engl J Med 1999;341(25):1882-90.

Entry Criteria

Total mortality (5 years)



Control

ICD

ICD benefit

0

10

20

30

40

MADIT II

2-y

ear

all-c

au

se m

ort

ality

(%

)

31%

MUSTT MADIT

54%51%

Relative reduction



Nonischemic

0

2

4

6

8

10

12

14

All-c

ause m

ort

ality

(%

)

CAT AMIOVERT

Control ICD



Two questions

Why has it not been possible to show a survival benefit with ICDs for nonischemic cardiomyopathy patients?

Why haven't more ICDs been used in primary prevention in light of the positive data from trials?

Prystowsky



Nonischemic sudden death

The mechanism for sudden death may not be the same in nonischemic patients; they are less likely to have a new ischemic event

The intermediate term prognosis for nonischemic patients seems to be better

• Arrhythmia mechanisms may be different

• Beta blockers may be more effective

• ICDs may give less "bang for the buck"

Dorian



Jury is still out

"We have to be very careful to remember that absence of proof is not the same as proof of absence."

It is not yet proven that patients with dilated cardiomyopathy benefit from ICDs as primary prophylaxis, but [there is] also no proof ICDs are useless in this population

Numerous upcoming trials may shed further light on the issue

Dorian



Primary prevention

"Clearly we don't know everything we need to know about the magnitude of benefit from implanted defibrillators"

Few doubt ICDs are effective

The question is the likelihood of a patient actually suffering sudden death

• If small, the overall benefit is small

• If large, the overall benefit is large

Dorian



Insurance metaphor

A wood house heated by coal or wood needs good fire insurance, while a brick house not heated often doesn't need fire insurance

"How likely do we think it is that patients at potential risk for sudden death will actually have ventricular defibrillation or VT and be rescued by their defibrillator?"

Dorian



CMS decision

CMS did a subgroup analysis of MADIT II to give only partial coverage of ICDs—similar to the house metaphor

With limited resources one must pick the patients who clearly will get the most benefit

"If defibrillators cost a buck a piece, we wouldn't have the argument."

Prystowsky



ICDs in Europe

Why are there different approaches to ICDs in Germany and France?

"It's more a philosophic issue than a medical issue."

"It doesn't make sense that there is a difference between France and

Germany and Italy; I cannot explain this."

Klein



Nonischemic cardiomyopathy

The progress of nonischemic cardiomyopathy is very difficult to predict

Patients with long-lasting nonsustained VT have a worse prognosis

We tend to give long-lasting nonsustained VT patients ICDs, even when they are nonischemic

• A personal opinion

Klein



Need more parameters

More parameters [are needed] to judge risk in nonischemic patients because they have a high risk of sudden death

There is the parameter of nonsustained VT indicating higher risk

Klein



Primary prevention

So far in Germany, any patient meeting the criteria have received an ICD, but this is changing toward a more careful husbanding of resources

"We have had no problems so far, but it's getting worse and we will probably be forced to do so."

Klein



CMS coverage

CMS decided to provide reimbursement for patients with MADIT II criteria but only those with a QRS duration of >120 ms

"Frankly, having reviewed the data in the literature so far, that does seem to at least be the wood house. It doesn't mean we shouldn't be protecting the

nonwooden houses."

Prystowsky



Optimal therapy

"We believe strongly that patients should be considered for prophylactic ICD if and only if their other therapies have been absolutely optimized."

In a practical sense, this means many patients recommended for ICDs are ruled out by this more stringent approach

Dorian



MIRACLE

End point Control group

95% CI CRT group

95% CI p

Quality-of-life score

-11.0 -16 to -7 -17.5 -21 to -14 0.02

NYHA class 0 -1 to 0 -1 -1 to –1 0.007

Change in 6-minute walk distance (m)

53 43 to 75 55 44 to 79 0.36

Young JB et al. JAMA 2003; 289:2685-2694.



COMPANION

Measure CRT (%) CRT-ICD (%)Mortality and hospitalization

19 19

Mortality 23.9 43.4

Relative reduction at 12 months:compared with control arm

ACC 2003



Biventricular ICD

COMPANION showed that resynchronization improves quality of life and performance, but only the defibrillator improves the survival

"You cannot prevent sudden death by just improving ventricular function. . . . And if I have to make the choice, I certainly would use the combined device in coronary artery disease patients."

Klein



Biventricular pacemakers

"I have yet to implant a biventricular pacemaker [for this group of people]."

The data showing an advantage in preventing sudden death with the ICD function are very clear

"Am I just being too aggressive?"

Prystowsky



Changing approach

"Our thinking has evolved in this topic."

We started doing a number of pacemaker-only devices, but evidence is mounting that improving ventricular function has only modest effects in preventing arrhythmia

The extra risks and costs of adding the ICD function are not dramatic, and we are implanting more biventricular ICDs

Dorian



Choosing patients

Patients who clearly are in severe heart failure despite optimal medical treatment we tend to give biventricular ICDs

Those who have QRS of 120 or so but no severe heart failure might not get the ICD function

Klein



The broader view

"It's important to not just see the data as they are published but also to be

able to put them in context with a world of experience."

Prystowsky



Secondary prevention

Patients with documented cardiac arrest, sustained VT, syncope in the EP lab

Randomized trials point toward ICDs as therapy for these patients

DAVID trial suggests not pacing the ventricle, selecting which device is left to the physician

Prystowsky



Primary prevention

Randomized trials show that in ischemic heart disease ICDs are the best choice for therapy

For the nonischemic patients, the data are still not in and more data are needed

Depending on your budget, how narrow your selection process is will vary

Prystowsky



Biventricular devices

The biventricular ICD prolongs life, not just a biventricular pacemaker

The selection for a given patient will depend on multiple factors

There are still situations where a doctor or investigator may pick a biventricular pacemaker only

Prystowsky



The EP Show: Which ICD for which patient? Part 2: Primary preventionEric Prystowsky MD

Director, Clinical Electrophysiology Laboratory St Vincent Hospital

Indianapolis, IN

Helmut Klein MD Head of Division of CardiologyOtto-von-Guericke Universität MagdeburgMagdeburg, Germany

Paul Dorian MD Professor of MedicineDivision of cardiologySt Michael's HospitalToronto, ON

Documents

EP Show – Aug 2003 ICDs – Primary prevention The EP Show: Which ICD for which patient? Part 2: Primary prevention Eric Prystowsky MD Director, Clinical