[Preventive drug therapy following coronary bypass surgery or PTCA]

Antiplatelet therapy to prevent occlusion of coronary bypass grafts is widely used. Though the value of this therapy after bypass surgery is not yet settled, some favourable results have been achieved. Many physicians continue to use the Mayo Clinic recommendations (peri- and postoperative administration of aspirin and dipyridamole) while others used dipyridamole and aspirin after surgery, and others use aspirin alone. It is now well established that pretreatment with platelet inhibitors is effective in lowering the incidence of acute vessel closure after angioplasty: Numerous drugs, including warfarin, aspirin and dipyridamole, aspirin and heparin, nifedipine, diltiazem and the experimental antiplatelet agent ticlopidine have proved ineffective in reducing the rate of restenosis after coronary angioplasty. Only high dose administration of an omega-3 fatty acid dietary supplement for 1 week before angioplasty lowers patients' risk for restenosis, but this therapy does not appear effective if begun the night before the procedure or done with somewhat lower dose. Until additional results are available, clinicians must treat patients on extrapolation from the published trials. Low-dose aspirin should be used for several weeks after the procedure. Careful attention to risk factor modification, especially smoking, lipid profile and diabetes control, seems essential in any long-term plan of management in the patient with coronary disease.