Percutaneous coronary procedures are frequently followed by the need for repeat procedures or bypass surgery for coronary artery renarrowing. Abciximab is a monoclonal antibody fragment directed against beta3 integrin and is known to have short-term protective effects against restenosis in patients undergoing coronary intervention procedures. Topol and colleagues performed a long-term follow-up study of patients who received abciximab during coronary angioplasty or directional atherectomy to evaluate its prolonged protective effects.
Patients who were at increased risk for ischemia during angioplasty or directional atherectomy were included in the study. At the time of the initial revascularization procedure, patients received 325 mg of aspirin, and intravenous heparin. They were then randomized to receive one of three regimens: placebo bolus and placebo infusion, abciximab bolus and placebo infusion, or abciximab bolus and abciximab infusion. The outcomes observed were death, myocardial infarction or need for urgent coronary revascularization. The authors performed the follow-up study 2.5 years after the index percutaneous coronary revascularization procedure. Questionnaires administered by study coordinators were used to collect long-term follow-up data.
A total of 2,099 patients were initially assigned to one of the three treatment groups. Long-term data were available in 662 patients in the placebo group, 663 patients in the abciximab bolus group and 678 in the abciximab bolus plus infusion group. Patients were followed for up to three years.
When all outcomes were considered together at one year, the abciximab bolus plus infusion group had a 19 percent reduction compared with the placebo group. The data indicate that during the first two years of follow-up, 12 coronary revascularization procedures were prevented in the group that received abciximab as a bolus and infusion, compared with the placebo group.
After three years of follow-up, the abciximab bolus plus infusion group had a 13 percent reduction in these outcomes compared with the placebo group. The abciximab bolus plus placebo infusion group did not have similar reductions. Similar beneficial results were apparent when each of the three outcomes was considered separately. Death occurred in 6.8 percent of patients receiving abciximab bolus plus infusion, in 8.0 percent of patients receiving abciximab bolus plus placebo and in 8.6 percent of patients receiving placebo. Myocardial infarction occurred in 10.7 percent of the study subjects receiving abciximab bolus plus infusion, in 12.2 percent of those receiving abciximab bolus plus placebo, and in 13.6 percent of those receiving placebo. Another revascularization procedure was needed in 34.8 percent of the patients who received abciximab bolus plus infusion, compared with 38.6 percent of those who received abciximab bolus only and 40.1 percent of those who received placebo only.
The authors conclude that abciximab is associated with an extended protective effect against death, myocardial infarction and the need for coronary revascularization in patients who receive this medication as a bolus and infusion before their initial coronary revascularization procedure.