Substrate Versus Trigger Ablation for Paroxysmal Atrial Fibrillation

Not Recruiting

Trial ID: NCT02169037


This is a prospective randomized study to assess the safety and efficacy of FIRM (Focal Impulse and Rotor Modulation)-guided ablation for the treatment of symptomatic atrial fibrillation (AF). The study hypothesis is that the efficacy of AF elimination at 1 year will be higher by ablating patient-specific AF-sustaining rotors and focal sources by Focal Impulse and Rotor Modulation (FIRM) compared to conventional ablation alone (wide-area PV isolation).

Official Title

Substrate Ablation (Focal Impulse and Rotor Modulation) Compared to Pulmonary Vein Isolation to Eliminate Paroxysmal Atrial Fibrillation: A Randomized Clinical Trial

Stanford Investigator(s)

Paul  J. Wang, MD
Paul J. Wang, MD

John R. and Ai Giak L. Singleton Director, Professor of Medicine (Cardiovascular Medicine) and, by courtesy, of Bioengineering



   - male or female >21 years

   - reported incidence of at least two documented episodes of symptomatic paroxysmal
   atrial fibrillation (AF) during the three months preceding trial entry (at least 1
   episode documented by 12-lead ECG or ECG rhythm strip)

   - women without childbearing potential or women of childbearing potential who are not
   pregnant per a serum HCG test

   - refractory to at least one Class I or III anti-arrhythmic medications. Drug doses must
   be therapeutic and stable

   - willingness, ability and commitment to participate in baseline and follow-up
   evaluations without participation in another clinical trial (unless documented
   approval received from both sponsors)

   - oral anticoagulation required for those subjects who have a score of two or more based
   on the following criteria (CHAD score):

      - Congestive heart failure (1 point)

      - hypertention (1 point)

      - age 75 years or older (2 points)

      - diabetes (1 point)

      - prior stroke or transient ischemic attack (2 points)

      - vascular disease (1 point)

      - age 65 years or older (1 point)

      - sex category: female (1 point)

   - patient is willing and able to remain on anti-coagulation therapy for a minimum of 3
   months post procedure for all subjects, and potentially indefinitely post procedure if
   the patient has CHAD score >or=2

   - signed informed consent after a full discussion of the risks and benefits of both
   therapy arms, and the concept of randomization

   - NYHA Class 0,I, II stable on medical therapy for > 3months

   - left atrial diameter
   - LVEF >or=40%

   - sustained AF during the procedure


   - atrial fibrillation from a reversible cause (e.g., surgery, hyperthyroidism,

   - cardiac or thoracic surgery within the past 180 days

   - AF secondary to electrolyte imbalance, thyroid disease

   - contraindication to Heparin

   - Contraindication to Warfarin or other novel oral anticoagulants

   - history of significant bleeding abnormalities

   - history of significant blood clotting abnormalities, systemic thrombi or systemic

   - ASD closure device, LAA closure device, prosthetic mitral or tricuspid valve

   - atrial clot/thrombus on imaging such as on a trans-esophageal echocardiogram (TEE)
   within 72 hours of the procedure

   - intramural thrombus or other cardiac mass that may adversely effect catheter
   introduction or manipulation

   - significant pulmonary embolus within 6 months of enrollment

   - acute illness or active systemic infection or sepsis that may ordinarily warrant
   postponement of the procedure

   - history of recent cerebrovascular disease (stroke or TIA) or systemic thromboembolism
   within < 6 months

   - NYHA classes III, IV

   - heart failure that is not stable on medical therapy

   - pulmonary edema, that may make planned anesthesia or sedation difficult

   - stable/unstable angina or ongoing myocardial ischemia

   - myocardial infarction (MI) within the past three months

   - structural heart disease of clinical significance including:

      - congenital heart disease where the abnormality or its correction prohibit or
      increase the risk of ablation

      - acquired heart disease that may increase risk of ablation, such as significant
      ventricular septal defect post myocardial infarction

      - rheumatic valve disease, since this produces a unique AF phenotype

      - extreme left atrial enlargement (LA volume index > 60 ml/m2) in whom PVI has low
      success and 55 mm baskets are too small for the atria

   - cardiac transplantation or other cardiac surgery planned within the 12 month followup
   period of the trial

   - life expectancy less than 12 months (the followup period of the trial)

   - significant pulmonary disease (e.g., COPD) or any other disease that significantly
   increase the risk to the patient from sedation or anesthesia

   - untreatable allergy to contrast media

   - at time of ablation procedure, clinically significant abnormalities in serum
   potassium, sodium, magnesium or other electrolytes that affect the suitability of the
   patient for ablation at that time


procedure: FIRM Ablation

procedure: Conventional AF ablation with PVI

Not Recruiting

Contact Information

Stanford University
School of Medicine
300 Pasteur Drive
Stanford, CA 94305