A 2008 study of patients with cardiovascular disease found that those who are naturally resistant to aspirin have a significantly increased chance of suffering a heart attack or stroke, or dying. Patients who are aspirin-resistant have blood cells used for clotting that aren’t affected by aspirin in the same way as people who are not resistant.

Study results showed that 39 percent of aspirin-resistant patients suffered from a cardiovascular event, compared to 16 percent of patients who were not resistant to aspirin.

The study also found that blood-thinning drugs like Clopidogrel or Tirofiban do not help aspirin-resistant patients.

Source: “Aspirin resistance boosts heart risks in cardiac patients,” Washington Post, January 18, 2008.