A Blinded Study to Evaluate Effect on Atrial Fibrillation Burden in Patients With Paroxysmal Atrial Fibrillation

Primary Purpose: Protocol designed to assess, by the use of long term non-invasive
beat-to-beat monitoring with the SEEQ Mobile Cardiac Telemetry (MCT) system, the effect of
BMS-919373 on the percent change from baseline relative to placebo of atrial fibrillation
burden in subjects with paroxysmal atrial fibrillation.

For more information regarding BMS clinical trial participation, please visit
www.BMSStudyConnect.com

Inclusion Criteria:

- Signed informed consent

- Paroxysmal Atrial Fibrillation (pAF) with available documentation of AF and reporting
symptoms within 6 months prior to screening

- Able to tolerate withdrawal of antiarrhythmic therapy (rhythm control)

- Echocardiographically measured left ventricular ejection fraction (LVEF)
≥40%,measured within 12 months of enrollment

- Echocardiographically measured left atrial (LA) diameter ≤ 5.0 cm, measured within 12
months of enrollment

Exclusion Criteria:

- Women of childbearing potential

- AFB < 3% or > 70%, during both screening periods independently

- Permanent or persistent Atrial Fibrillation

- Cardioversion within 3 months of study drug administration

- Stroke within 12 months of study drug administration

- TIA within 12 months of study drug administration

- Heart failure of NYHA class III or greater (symptoms of heart failure at rest or with
minimal exertion)

- Heart failure of NYHA class II (symptoms of heart failure with routine levels of
exertion)with ejection fraction <40% as measured by echocardiography at any time
within 12 months of study enrollment (i.e. additional ejection fraction measurements
≥ 40% over this period will not counter this exclusion)

- Valvular heart disease (including any valvular insufficiency or stenosis greater
than"mild")

- Ablation within 3 months of study enrollment