Metformin as an Adjunctive Therapy to Catheter Ablation in Atrial Fibrillation

Inclusion Criteria:

• Body Mass Index (BMI) >25 kilograms / square meter (kg/m2) with plan for rhythmcontrol of atrial fibrillation by catheter ablation

• All subjects must be able to understand and willing to sign a written informedconsent document.

Exclusion Criteria:

• Individuals who are already taking metformin or other antidiabetic medications,including insulin

• Known diabetes

• Known allergy or Food and Drug Administration (FDA)-labeled contraindication totaking metformin (estimated glomerular filtration rate (eGFR)<30 millilitres perminute (mL/min)/1.73 square meters (m2), hypersensitivity to metformin, acute orchronic metabolic acidosis)

• Patients taking carbonic anhydrase inhibitors

• eGFR below 30 mL/min per 1.73 m2 or other clinical diagnosis of advanced renaldisease

• Acute or chronic metabolic acidosis (serum bicarbonate <22 milliequivalents perliter (mEq/L))

• History of significant alcohol use (>2 drinks/day on average)

• History of hepatic dysfunction (serum bilirubin 1.5 times greater than ULN)

• History of New York Heart Association (NYHA) Class III or IV heart failure

• Pregnancy or nursing