In the post-market environment, the RCT design did not allow achievement of enrollment goals

The study purpose is to demonstrate that ventricular tachycardia (VT) ablation using the Niobe™ ES system results in superior outcomes compared to a manual approach in subjects with ischemic scar VT in a low ejection fraction population.

This study is a randomized, single-blind, prospective, multi-center post market evaluation. Subjects will be screened for study eligibility and asked to complete written informed consent prior to any study specific testing assessments. After completing written informed consent, a total of 386 subjects will be randomized on a 1:1 basis to receive VT ablation treatment using either the Niobe ES or standard manual catheter ablation treatment using commercially available products. This will be the largest randomized VT study comparing outcomes from RMN to manually guided catheter ablation procedures. Subjects will be randomized according to a computer-generated randomization scheme. Randomization will be blocked at the study site level and subjects will be blinded to group assignment. Since quality of life measurements will be collected during follow-up, this study is single-blinded in order to mitigate patient bias. Clinical evaluations will not be masked to the treating physician.

Inclusion Criteria:

• subject has had an ICD previously implanted
• subject has drug-refractory monomorphic VT
• subject is a candidate for ischemic VT RF ablation
• subject has had a myocardial infarction
• subject has a LVEF less than or equal to 35%

Exclusion Criteria:

• subject has non-ischemic VT
• subject has a history of stroke within 1 month prior to enrollment
• subject has had an acute myocardial infarction within 30 days prior to enrollment
• subject has unstable angina
• subject has undergone cardiac surgery within 60 days prior to enrollment
• subject is pregnant or nursing
• subject has a limited life expectancy of 1 year or less (Subjects requiring LVAD/IABP intraprocedural support may be enrolled as long as life expectancy is at least 1 year following the ablation procedure.)
• subject is unable or unwilling to cooperate with study procedures
• subject has a known presence of intracardiac thrombi as determined by echocardiography
• subject has a major contraindication to anticoagulation therapy or coagulation disorder
• subject has had a previous pericarditis or cardiac tumor
• subject has had previous thoracic radiation therapy
• any other reason the investigator considers the subject ineligible