Attainment and maintenance of platelet inhibition through standard dosing of abciximab in diabetic and nondiabetic patients undergoing percutaneous coronary intervention

Background-Although the effectiveness of abciximab (c7E3 Fab; ReoPro) in la rge populations of patients undergoing a percutaneous coronary intervention has been consistently proved in clinical trials, it is unknown whether all patients achieve and maintain target inhibition during treatment. Diabetic patients in particular are a subgroup of patients with known underlying pl atelet abnormalities whose long-term response to abciximab has been shown t o vary from that of nondiabetic patients. Methods and Results-Forty-nine diabetic and 51 nondiabetic patients who rec eived adjunctive abciximab therapy during percutaneous coronary interventio ns were evaluated prospectively. The degree of platelet function inhibition was determined immediately after the abciximab bolus, 8 hours after the bo lus (during the 12-hour abciximab infusion), and the next morning (13 to 26 hours after the bolus) with the use of a rapid platelet function assay (Ac cumetrics). After the abciximab bolus, platelet function was inhibited by 9 5 +/- 4% (mean +/- SD). By 8 hours, the average percent inhibition had decr eased to 88 +/- 9%, with 13% of patients with <80% inhibition. The next mor ning (mean 19 hours after the bolus), mean inhibition was 71 +/- 14%. A dif ference was not found between diabetics and nondiabetics, nor was any physi ological parameter found to be predictive of the response to abciximab. Conclusions-Although the majority of patients achieve and maintain greater than or equal to 80% platelet inhibition during the 12-hour infusion with s tandard-dose abciximab, there is substantial variability among patients. Di abetic status does not appear to influence this variability.