According to studies done, antiplatelet therapy with aspirin reduced the risk of secondary stroke
and MI significantly. And studies
have also shown lower doses of aspirin are as effective as higher doses. Doses of 75 to 150 mg/day produced the same risk reduction, compared with placebo, as doses of 150 to 325 mg/day. Lower doses also reduce the risk of bleeding tendencies. As your father has been stable, his treating doctor may consider dosage reduction, please discuss this with him.