OMISSION OF ASPIRIN IN PATIENTS FOLLOWING CORONARY-ARTERY BYPASS GRAFT-SURGERY

Graft patency is a major factor contributing to the long-term results of coronary artery bypass graft (CABG) surgery. The systematic overvie w of the Antiplatelet Trialists' Collaboration provides evidence that antiplatelet therapy reduces by nearly one-half the odds of coronary g raft occlusion following CABG. We retrospectively reviewed patients un dergoing CABG during 1993 at the Cardiothoracic Unit, Northern General Hospital, to determine the incidence of, and indications for, aspirin omission following CABG: 462 patients with isolated CABG, 75 patients with a combined CABG and a heart valve procedure and 21 patients with a combined CABG and other non-valve procedure. Thirty-six patients (7 .5%) with isolated CABG and CABG combined with a non-valve procedure w ere not prescribed aspirin. The reasons for aspirin omission were cate gorized into three groups depending on whether omission was fully just ified (group 1), possibly justified (group 2) or unjustified (group 3) . Twenty-one patients were in groups 2 and 3, nine of whom were starte d on aspirin 2-6 weeks after discharge without any ill effect. Forty-t wo patients were discharged from hospital on a three month course of w arfarin. Four months later four patients had died, 24 had changed to a spirin, 10 were still on warfarin and four were on neither drug. Aspir in was sometimes omitted without clear indications. Better provisions for supervision should be made by either the General Practitioner or H ospital Practitioner during the change-over period from oral anticoagu lation to antiplatelet therapy in patients on a short course of warfar in.