Our understanding of preconditioning mechanisms suggests that several pathways may be amenable to pharmacological manipulation in patients at risk of myocardial ischemic episodes. Potential approaches include stimulation of the adenosine A1 receptor and opening of the ATPsensitive K+ channel, both of which have been implicated in experimental preconditioning. Identification of suitable patient groups is important since any preconditioning therapy must be administered before the myocardial ischemic episode. We suggest that two populations may be amenable to such therapy initially: patients undergoing elective procedures involving scheduled ischemia, such as coronary artery bypass grafting, and patients with unstable angina, who are at risk of subsequent ischemic events. Clinical trials sensitive enough to detect clinical benefit should be designed to test such therapies in the context of other therapeutic strategies...