Heparin infusion prior to stenting (HIPS) trial: Final results of a prospective, randomized, controlled trial evaluating the effects of local vascular delivery on intimal hyperplasia

Background local delivery of pharmacologic agents or genes at the site of a ngioplasty is a promising approach to reduce restenosis. However, there are unresolved questions concerning the safety and feasibility of local vascul ar delivery in clinical practice as well as the efficacy of delivered drug. To this end, the safety, feasibility, and efficacy of local delivery of he parin were evaluated in the Heparin Infusion Prior to Stenting (HIPS) trial . Methods and Results A total of 179 patients were enrolled in this multicent er, randomized, prospective, core laboratory- evaluated trial. Patients wer e randomly assigned to 5000 U heparin either administered to the coronary a rtery lumen or infused into the arterial wall immediately after angioplasty and before stent placement. End points included procedural events and clin ical, angiographic, and intravascular ultrasound events at 6 months. Patien t groups were evenly matched. There was no difference in the incidence of a rterial injury, defined as an increase in arterial dissection, acute closur e, or decrease in Thrombolysis In Myocardial Infarction grade blood flow in the group receiving local delivery. At follow-up there was no difference i n the major adverse event rate between intraluminal (22.7%) and local group s (24.7%). There was no difference between intraluminal and local therapy i n the angiographic in-stent restenosis rate (12.5%, 12.7%) or the in-stent volumetric analysis by intravascular ultrasound (IVUS) (37. 19 +/- 20.86 mm (3) vs 43.79 +/- 25.52 mm(3)). Conclusions Local delivery of 5000 U heparin into the arterial wall before stent implantation is safe and feasible. There was not a favorable effect o f locally delivered heparin on clinical, angiographic, or IVUS end points o f restenosis. The use of IVUS to measure volume of intimal hyperplasia in a multicenter, core laboratory-controlled trial is feasible.