Indications for ICD therapy

Raja Selvaraj, JIPMER

Sudden death

  • About a 1000 people attending this conference
  • One of us is likely to die suddenly in the next one year (1)
  • Most likely to happen outside the hospital
  • Rhythm is VF if recorded within 4 minutes (2)
  • We could implant ICDs in everyone to prevent that death
  • Or we could learn to identify those most likely to benefit
  1. Becker et al. Annals of Emergency Medicine 1993;22:86-91
  2. Hallstrom et al. Emerg Health Services

Sources

  • ACC / AHA guidelines (2008, update 2012) (1, 2)
  • ESC guidelines (2015) (3)
  • Appropriate use criteria (2013) (4)
  • Original studies
  1. Circulation 2008;117:e350-e40
  2. Circulation 2012;12
  3. Eur Heart J (2015) 36 (41): 2793-2867
  4. Heart Rhythm, Vol 10, No 4, April 2013:e11

Case 1

  • Two patients and one ICD
  • 40 M, Sustained VT, old MI, LVEF 35%, NYHA I
  • 40 M, MI 1 yr back, LVEF 25%, NYHA I
  • Who gets the ICD ?

Secondary prevention vs primary prevention

How much better is NNT ?

  • 2 times (half)
  • 3 times (third)
  • 5 times
  • 10 times

NNT in ICD trials

Trial Mortality(3yrs) NNT(3yrs)
MADIT2 31 11
SCD-HeFT (ICM) 28 18
SCD-HeFT (NICM) 15.8 25
MADIT 42 4
MUSTT 35.4 5
AVID 35.9 9
CIDS 27 27
CASH 39 13
Metaanalysis 32 13

Betts et al. Absolute risk reduction in total mortality with implantable cardioverter defibrillators: analysis of primary and secondary prevention trial data to aid risk/benefit analysis. Europace 2013; 15 (6): 813-819

ACC guidelines

  • LV dysfunction / prior MI / at least 40 days post-MI / LVEF less than or equal to 30% / NYHA functional Class I. (Class I Level of Evidence: A)
  • Structural heart disease / spontaneous sustained VT / Hemodynamically stable or unstable. - (Class I Level of Evidence: B)

Case 2

  • 36 male, AWMI
  • VF on second day - defibrillated
  • LVEF 30%

Family apprehensive, what would you do?

  • ICD for secondary prevention?
  • ICD for primary prevention?

Primary VF - No indication for ICD

  • Related to reversible trigger
  • Does not affect long term outcome
  • ICD implant not indicated on this basis

Primary prevention?

  • MADIT 2 requires 40 days post MI
  • Early ICD implant not shown to be beneficial

ICD early post MI

dinamit_iris.jpg

  1. Hohnloser et al. Prophylactic Use of an Implantable Cardioverter–Defibrillator after Acute Myocardial Infarction (DINAMIT) N Engl J Med 2004; 351:2481-2488
  2. Steinbeck et al. Defibrillator Implantation Early after Myocardial Infarction (IRIS) N Engl J Med 2009; 361:1427-1436

Outcome?

  • What is his prognosis?
  • What would you do

Not benign !

  • AIVR - benign
  • Primary VF - poor acute outcome
  • But does not impact long term outcome

Fast MI registry - 5 year analysis of outcomes

fast_mi_front.png

Higher early mortality

fast_mi_early_mortality.png

Long term outcome not affected

fast_mi_late_mortality.png

What would you do?

  • Revascularization
  • Beta blockers
  • Early risk stratification ?

Appropriate use criteria for ICD implant

appropriate_early_vt.png

Wearable defibrillator

wearable_defib.jpg

Case 3

  • 75 year old male
  • Old MI
  • LVEF 30%, NYHA III
  • Creat 2.2, BUN 45
  • RBBB, QRSd 140 ms
  • Persistent atrial fibrillation

ICD advised elsewhere

  • ICD indicated as per guidelines
  • Can you deny ICD because of age?
  • What would you advise?

HF severity and benefit

levy_scdheft.jpg

Levy et al. Circulation 2009;120:835-842

Other risk markers and U curve

Goldenberg - MADIT II

  • Age > 70 yrs
  • NYHA > II
  • BUN > 26 mg/dl
  • QRS d > 120 ms
  • Atrial fibrillation

Goldenberg et al. JACC 2008;51:288-296

Other risk markers and U curve

goldenberg.png

Seattle Heart Failure Model may be a better predictor

Application and comparison of the FADES, MADIT, and SHFM-D risk models for risk stratification of prophylactic implantable cardioverter-defibrillator treatment. Europace (2017) 19 (1): 72-80

Case 4

  • 45 M
  • Old AWMI
  • LVEF 32%, NYHA II
  • 20% PVCs, short NSVT on holter
  • What would you advise

Is there an indication for ICD?

  • LVEF < 30%, NYHA I (MADIT 2)
  • LVEF < 35%, NYHA II-III (SCD-HeFT)
  • EP study (MADIT / MUSTT)
  • ICD implant ?

Ablation of PVCs

pvc_ablation1.png

Ablation of frequent PVC in patients meeting criteria for primary prevention ICD implant: Safety of withholding the implant. Heart Rhythm 2015;12:2434–2442

May obviate need for ICD implant!

pvc_ablation2.png

Case 5

  • 28 year old male
  • Recurrent syncope

ECG

lqts2.jpg

Management?

  • Lifestyle modification
  • Beta blockers
  • Sympathectomy
  • ICD implantation

ICD implant in LQTS

  • Syncope or VT while receiving beta blockers (IIa)
  • Doing well 4 years later, on high dose beta blockers

Conclusion - When not to implant an ICD

  • Expected survival with good functional status < 1 yr
  • Incessant VT / VF
  • Drug refractory class IV failure, not candidate for CRT / transplant
  • VT / VF amenable to ablation
  • Arrhythmias due to completely reversible cause