Surgical Ablation Versus No Surgical Ablation for Patients With Atrial Fibrillation Undergoing Mitral Valve Surgery

The purpose of this study is to determine whether the addition of surgical ablation to
planned mitral valve surgery for patients with persistent or longstanding persistent AF
(within 6 months prior to randomization) reduces the incidence of postoperative heart
arrhythmia compared to mitral valve repair with medication therapy alone. This is a
randomized, multi-center trial which will enroll 260 subjects who will be randomized in a
1:1 fashion to: (a) mitral valve surgery plus surgical ablation or (b) mitral valve surgery
without ablation (control group). All patients will undergo ligation or excision of the
left atrial appendage. Patients assigned to the ablation group will be further randomized
(1:1) to one of two lesion sets: (1) pulmonary vein isolation only or (2) biatrial Maze
lesions. The target population for this trial consists of adult patients with mitral valve
disease requiring surgical intervention and persistent or longstanding persistent atrial
fibrillation. All patients who meet the eligibility criteria may be included in the study
regardless of gender, race or ethnicity. The primary efficacy endpoint is freedom from AF,
which will be measured by 3-day continuous monitoring at 6 months and 12 months
post-ablation. The primary safety endpoint is a composite of death, stroke, serious cardiac
events (heart failure, myocardial infarction), cardiac re-hospitalizations, transient
ischemic attack, pulmonary embolism, peripheral embolism, excessive bleeding, deep sternal
wound infection/mediastinitis, damage to specialized conduction system requiring permanent
pacemaker, damage to peripheral structures, such as the esophagus, within 30 days
post-procedure or hospital discharge (whichever is later).

Inclusion Criteria:

- Able to sign Informed Consent and Release of Medical Information forms

- Age ≥ 18 years

- Clinical indications for mitral valve surgery for the following:

1. Organic mitral valve disease; or

2. Functional non-ischemic mitral regurgitation; or

3. Ischemic mitral regurgitation with evidence of concomitant structural mitral
valve disease

Note: May include need for surgical management of functional tricuspid regurgitation or
patent foramen ovale. May also include concomitant CABG, aortic arch or aortic valve
procedure. Surgical intervention may be performed via sternotomy or minimally invasive
procedure.

- a) Persistent AF within 6 months prior to randomization, defined as non
self-terminating AF lasting greater than 7 days but no more than one year, or lasting
less than 7 days but necessitating pharmacologic or electrical cardioversion.

- Duration of AF must be documented by medical history and

- Presence of AF must be documented by a direct electrocardiographic assessment
within 6 months prior to randomization.

- b) Longstanding persistent AF is defined as continuous AF of greater than one year
duration.

- Duration of AF must be documented by medical history and

- Presence of AF must be documented by a direct electrocardiographic assessment
upon arrival in the OR.

- Able to use heart rhythm monitor

Exclusion Criteria:

- 1. AF without indication for mitral valve surgery 2. AF is paroxysmal 3. Evidence of
left atrial thrombus by intra-operative TEE 4. Evidence of active infection 5. Mental
impairment or other conditions that may not allow subject to understand the nature,
significance, and scope of study 6. Surgical management of hypertrophic obstructive
cardiomyopathy 7. Previous catheter ablation for AF 8. Life expectancy of less than
one year 9. Absolute contraindications for anticoagulation therapy 10. Enrollment in
concomitant drug or device trials 11. Uncontrolled hypo- or hyperthyroidism 12. FEV1
< 30% of predicted value and/or need for home oxygen therapy 13. Women who are
pregnant as evidenced by positive pregnancy test 14. Women of childbearing age who do
not agree to be on adequate birth control throughout the period of the trial.