Resistance to what, does it matter? How do we study it?

The importance of platelets and thrombosis in the pathophysiology of acute ischaemic coronary syndromes has been well appreciated. This information has formed the backbone of the guidelines on both sides of the Atlantic that patients with acute as well as chronic coronary artery disease be treated with aspirin as a long-term strategy of care. While the specific dosage schedule may vary, aspirin treatment remains a Class I indication.1 Increasingly, adherence to this as well as other guidelines is a measure of quality of care. The issue of platelet function and thrombosis has become more complicated in the era of stent-based percutaneous coronary intervention (PCI);2–4 this is a particular issue regarding the problem of stent thrombosis, a subject which has attracted tremendous scientific, lay press, and patient as well as regulatory interest. This interest has been stimulated by several factors:5,6 (i) stent placement is the procedure of choice for … *Corresponding author. Tel: +1 507 255 2504, Fax: +1 507 255 2550, Email: dholmes{at}mayo.edu