IMPACT Trial: angiographic and intravascular ultrasound observations of the first human experience with mycophenolic acid-eluting polymer stent system

The purpose of the study was to examine the safety and efficacy of two different formulations of mycophenolic acid (MPA)-eluting Duraflex stents on coronary de novo lesions. Recent data indicate that local delivery of MPA in the porcine overstretch coronary model significantly reduces neointimal hyperplasia (NIH). Patients were divided into three consecutive groups. The first (n=50) and second (n=55) groups received moderate- and slow-release MPA-eluting Duraflex stent, respectively. The last group (n=50) received the bare metal Duraflex stent. Clinical, angiographic, and intravascular ultrasound analysis were performed at 6-month follow-up. All stents were successfully deployed and patients were discharged home without clinical events. Compared to controls, 6-month in-lesion and in-stent minimum luminal diameter as well as late lumen loss were not significantly different in the moderate- and slow-release treatment groups. At follow-up, percentage obstruction and NIH volume were also similar between the three groups. At 30 days and 6 and 12 months, there were no differences noted between the three groups with respect to major adverse cardiac events as well as the individual rates of mortality, myocardial infarction, or repeat revascularization. There were no cases of subacute or late thrombosis. In this feasibility trial, the MPA-eluting Duraflex stents in either slow- or moderate-release formulations were well tolerated, but showed no benefit for treatment of coronary lesions when compared to controls. Further testing with different drug dosing or delivery rate might improve these results.