A 72-year-old man presents with new-onset atrial fibrillation detected incidentally on examination. He has a history of hypertension but no heart failure, diabetes, or prior stroke. Blood pressure is 138/82 mm Hg, heart rate 110 beats per minute and irregular. His CHADS2 score is 1. According to the Canadian Cardiovascular Society atrial fibrillation guideline and the CHADS-65 algorithm, what is the most appropriate stroke prevention strategy?