In Ischemic VT, Catheter Ablation is as Important as AAD and AICD

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Raja Selvaraj, JIPMER

Ischemic VT

  • Sustained ventricular tachycardia in patients with prior MI
  • Usually some degree of LV dysfunction
  • Significant contributor to morbidity and mortality
  • Mechanism - Reentry related to myocardial scar

Ischemic VT treatment options

  • Revascularization
  • Anti-arrhythmic drugs
  • AICD implant (to prevent sudden death)
  • Catheter ablation

Management scenarios

  • First presentation with VT
  • Recurrent VT after AAD and ICD
  • VT storm

Patient with first episode of VT

  • ICD indicated (Secondary prevention)
  • AVID / CIDS / CASH

Why is ICD not sufficient ?

  • Shocks are painful and decrease QOL
  • Associated with increased mortality (1)
  • Recurrent VT may itself result in sudden death despite ICD

Sweeney et al. Differences in effects of electrical therapy type for ventricular arrhythmias on mortality in implantable cardioverter-defibrillator patients. Heart Rhythm 2010;7:353–360

Prevention of recurrences

  • Antiarrhythmic drugs alone
  • Ablation alone
  • Antiarrhythmic drugs + ablation

Ablation for ischemic VT - Outcomes

  • Well established and standardized procedure
  • Success rate about 75%
  • Reduced VT frequency in most others
  • Major complications in 1%

Only ablation as first strategy - VTACH trial

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VTACH trial

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Kuck KH, Schaumann A, Eckardt L, et al. Catheter ablation of stable ventricular tachycardia before defibrillator implantation in patients with coronary heart disease (VTACH): a multicentre randomised controlled trial. Lancet. 2010;375:31-40.

SMASH VT - Similar results

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Vivek Reddy et al. Prophylactic Catheter Ablation for the Prevention of Defibrillator Therapy. N Engl J Med 2007; 357:2657-2665

Ablation in addition to drugs

  • AAD reasonable as first line instead of ablation
  • Multiple studies on additional ablation in these patients
  • Less VT recurrence with additional ablation vs drugs alone (1)
  • Trend towards lesser mortality

Mallidi J, Nadkarni GN, Berger RD, et al. Meta-analysis of catheter ablation as an adjunct to medic al therapy for treatment of ventricular tachycardia in patients with structural heart disease. Heart Rhythm. 2011;8:503-10

Metaanalysis

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Recurrence on drugs - VANISH TRIAL

  • Ischemic VT / ICD / VT recurrence on drugs
  • Drug escalation or ablation ?
  • Drug escalation
    • Not on amiodarone -> Amiodarone
    • Amiodarone < 300 mg / d -> 300 mg / d
    • Amiodarone 300 mg / d -> Mexilitene added

Sapp JL, Wells GA, Parkash R, et al. Ventricular tachycardia ablation versus escalation of antiarrhy thmic drugs. N Engl J Med. 2016;375:111-21

VANISH - Primary outcome - Death + VT storm + Appropriate shock

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Sapp JL, Wells GA, Parkash R, et al. Ventricular tachycardia ablation versus escalation of antiarrhy thmic drugs. N Engl J Med. 2016;375:111-21

Especially marked in patients on Amiodarone

VANISH - Outcomes

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Sapp JL, Wells GA, Parkash R, et al. Ventricular tachycardia ablation versus escalation of antiarrhy thmic drugs. N Engl J Med. 2016;375:111-21

VT storm

  • 3 or more arrhythmia episodes within a 24 hour period
  • 10 - 20% of patients with an ICD
  • Sympathetic blockade / AAD
  • Ablation useful as rescue strategy

Schreieck J et al. Rescue ablation of electrical storm in patients with ischemic cardiomyopathy: a potential-guided ablation approach by modifying substrate of intractable, unmappable ventricular tachycardias. Heart Rhythm 2005; 2: 10-4

Summary

  • ICD is indicated in all patients with sustained VT after previous MI
  • ICD is not intended to treat VT
  • AAD useful for arrhythmia suppression, limited by
    • Incomplete effectiveness
    • Pro-arrhythmic effects
    • Long term toxicity
  • Catheter ablation safe and effective, therefore plays a significant role in
    • AAD failure
    • Avoid AAD
    • Help taper and stop AAD

JIPMER Protocol

  • First presentation with VT
    • AICD
    • Amiodarone 200 mg OD + beta blockers
    • Consider ablation in case of recurrent episodes
  • Recurrence on Amiodarone
    • Catheter ablation

JIPMER experience

  • Jan 2010 to Mar 2018
  • RF ablation for Previous MI with sustained VT - 49 patients
  • Successful first ablation - 44, partial success in 3
  • Procedural complications - Nil
  • Recurrence - 7 patients

Illustrative case

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