A 68-year-old man with hypertension and type 2 diabetes presents for follow-up after a 24-hour Holter confirmed paroxysmal atrial fibrillation. His CHA₂DS₂‑VASc score is 3 (age 65-74, hypertension, diabetes). Creatinine is 1.2 mg/dL (eGFR 62 mL/min/1.73 m²). What is the most appropriate next step to reduce his stroke risk?