Pilot Study of Catheter Ablation for Ventricular Tachycardia in Patients With an Implantable Cardioverter Defibrillator

This study will be conducted at up to 8 sites and will randomize 50 patients over 1 year to
a strategy of catheter ablation (n=25) vs. state-of-the-art pharmacologic therapy (n=25). To
be considered for enrollment in this pilot trial, patients must be at least 18 years of age
and must have an ICD for a primary or secondary prevention indication, have ≥ 1 documented
ICD shock or ≥ 3 ATP therapies for VT in the absence of a reversible cause that in the
opinion of the treating physician requires further therapy and be eligible for both catheter
ablation and at least 1 antiarrhythmic medication. Patients will be followed at 3 and 6
months and their vital status will be determined via a phone call at 12 months. Data on the
safety and efficacy of therapies used in the pilot study will be collected. Of particular
interest are adverse events resulting from the catheter ablation procedure and major side
effects from antiarrhythmic medications.

Inclusion Criteria:

- Have an ICD with or without cardiac resynchronization therapy (i.e. CRT-D) for a
primary or secondary prevention indication

- Have ischemic heart disease defined as the presence of wall motion abnormalities and
documented coronary artery disease (one ≥ 70% stenosis in ≥ 1 major coronary artery)

- Have ≥ 1 documented ICD shock or ≥ 3 ATP therapies within 6 months before
randomization for VT in the absence of a reversible cause that in the opinion of the
treating physician requires further therapy. The VT has to be monomorphic and at a
rate of ≤ 260 bpm.

- Be at least 18 years of age

- Be eligible for catheter ablation

- Have no history of intolerance or contraindication to at least 1 of the following
antiarrhythmic medications: amiodarone, sotalol, and mexiletine.

Exclusion:

- Patients who in the opinion of the treating physician should not receive additional
therapy

- More than 30 days of amiodarone treatment in the past 3 months unless the patient has
been on ≤ 200 mgs of amiodarone daily for atrial arrhythmias or premature ventricular
contractions (PVCs) and the patient is eligible for a higher dose of amiodarone

- Incessant VT that necessitates immediate treatment

- Reversible causes of VT including but not limited to ischemia, decompensated HF, and
electrolyte disturbances

- The presence of a contraindication to catheter ablation of VT (including the presence
of a mobile ventricular thrombus; an acute MI, coronary revascularization, or a
stroke in the preceding 30 days; unstable angina or NYHA class IV HF; a mechanical
valve; or inability to receive anticoagulation or antithrombotic therapy)

- Patients with non-ischemic cardiomyopathy

- Patients with hypertrophic obstructive, restrictive, or infiltrative cardiomyopathy

- Patients with acute myocarditis, congenital heart disease, valvular disease likely to
require surgery in the next 1 year, and/or inoperable obstructive valvular disease

- Patients with a heart transplant or who are expected to undergo cardiac
transplantation within 12 months

- Patients with a left ventricular assist device

- Patients who are already on antiarrhythmic drug therapy (other than beta-blockers)
for VT (patients will not be excluded if they are receiving antiarrhythmic drug
therapy for atrial arrhythmias or PVCs if they are eligible for additional drug
therapy for VT).

- Heritable arrhythmias or increased risk for torsade de pointes with class III drugs

- End stage renal disease requiring dialysis

- Estimated life expectancy of <1 year from a non-cardiac cause

- Women who are pregnant or who have childbearing potential and are not using a
reliable method of contraception

- Inability to give informed consent