Botulinum Toxin Type A (AGN-151607) for the Prevention of Post-operative Atrial Fibrillation in Patients Undergoing Open-chest Cardiac Surgery (NOVA)

Inclusion Criteria:

- Capable of giving signed informed consent, which includes compliance with the
requirements and restrictions listed in the informed consent form.

- Written informed consent from the participant has been obtained prior to any
study-related procedures

- Written documentation has been obtained in accordance with the relevant country and
local privacy requirements, where applicable (eg. Written Authorization for Use and
Release of Health and Research Study Information [US sites] and written Data
Protection consent (European Union sites).

- Participants who are scheduled to undergo open-chest cardiac surgery. Including
(coronary artery bypass graft (CABG) and/or valve repair/replacement).

- A male participant must agree to use contraception until Day 60 and refrain from
donating sperm during this period.

- A female participant is eligible to participate if she is not pregnant (has a negative
urine pregnancy result prior to randomization) not breastfeeding, and at least 1 of
the following conditions applies:

1. Not a woman of childbearing potential (WOCBP).

2. A WOCBP who agrees to follow the contraceptive guidance until after Day 60.

- In sinus rhythm for the last 48 hours prior to surgery (prior history of paroxysmal
atrial fibrillation (AF) is acceptable).

- Willing to wear an electrocardiogram (ECG) patch for 30 days post-surgery and for 7
days after each study visit

- Able, as assessed by the investigator, and willing to follow study instructions and
likely to complete required study visit.

Exclusion Criteria:

- Any medical condition that may put the participant at increased risk with exposure to
botulinum toxin type A, including diagnosed muscular dystrophy (eg, Duchenne's
muscular dystrophy), myasthenia gravis, Eaton-Lambert syndrome, amyotrophic lateral
sclerosis, mitochondrial disease, or any other significant disease which might
interfere with neuromuscular function.

- Participants with presence or history of any of the following within 3 months prior to
the Day 1 visit that may indicate a vulnerable respiratory state per the
investigator's clinical judgment: aspiration pneumonia, lower respiratory tract
infections, uncontrolled asthma, severe chronic obstructive pulmonary disease, or
otherwise compromised respiratory function.

- Permanent/persistent atrial fibrillation (AF)

- Has a known allergy or sensitivity to any botulinum toxin type A preparation.

- Has a known allergy or sensitivity to medical adhesive (eg, ECG patch adhesive;
hydrogel-based adhesive).

- Severe (> 55mm) atrial enlargement

- Left ventricular ejection fraction (LVEF) < 25%

- Presence or history of symptomatic atrioventricular block > 1st degree within the last
30 days

- Class I or III antiarrhythmic drugs unless proper washout was documented

- Botulinum toxin type A (of any serotype) use within 6 months of randomization

- Has been immunized for any botulinum toxin type A serotype as determined by
participant medical history

- Preoperative need for inotropes/vasopressors or intra-aortic balloon pump

- Prior cardiac surgery

- History of ablation for AF

- Planned ablation procedure for AF at the time of surgery

- Emergency surgery

- Current enrollment in an investigational drug or device study or participation in such
a study within 30 days of entry into this study

- Impaired prognosis defined as EuroSCORE II greater than 7% perioperative mortality

- Females who are pregnant, nursing, or planning a pregnancy during the study