Enhancement of platelet inhibition of ticlopidine plus aspirin vs aspirin alone given prior to elective PTCA

Abstract

Background. In many patients today, elective percutaneous transluminal coronary angioplasty is followed by implantation of coronary stents to achieve optimal results. The current medical strategy to prevent early reocclusion is the inhibition of platelet aggregation by administration of ticlopidine, in addition to aspirin, immediately after the procedure. In order to inhibit platelet aggregation as early as possible, many centres begin to treat patients with additional ticlopidine the day before elective coronary intervention. The aim of this study was to determine the effect of this strategy on platelet aggregation before angioplasty. Method. Fifty-two consecutive patients admitted to hospital for elective balloon angioplasty were prospectively randomized to receive either standard oral aspirin 100 mg per day or standard therapy plus 250 mg ticlopidine at the time of admission and the morning before angioplasty. Adenosine diphosphate-, collagen- and epinephrine-induced platelet aggregation was measured immediately before the procedure by an investigator who was blinded concerning the arm of therapy. Results. The two groups of patients were comparable in terms of age, sex, body mass index, anginal state, time interval between application of study drug and coronary intervention. Patients on aspirin and ticlopidine had a mean maximal platelet aggregation of 36 ± 12% with adenosine diphosphate as agonist. For the control group, 54 ± 12% was measured (P < 0.001). Myocardial infarction or emergency coronary bypass grafting did not occur in either group. Local haemorrhagic complications at the arterial access site occurred in five (aspirin) and six (aspirin and ticlopidine) patients (P = ns) none of them requiring blood transfusion. Conclusion. The additional application of ticlopidine to chronic aspirin therapy the day before elective coronary balloon angioplasty leads to a significantly higher inhibition of platelet aggregation at the time of the intervention. It seems to be safe compared to the standard procedure.