Hausleiter J et al. (2005) Prevention of restenosis by a novel drug-eluting stent system with a dose-adjustable, polymer-free, on-site stent coating. Eur Heart J 26: 1475–1481

Drug-eluting stents (DESs) have been shown to reduce the incidence of in-stent restenosis significantly compared with conventional bare-metal stents. Restenosis remains significant in patients at high risk for this occurrence, however, and there are concerns that the use of fixed drugs and doses in different patient subgroups could reduce the efficacy of DESs, while the use of polymer coatings could increase late complications. The Munich-based ISAR PROJECT tested a novel DES system that allows the physician to choose a patient-specific drug and dose, and permits a polymer-free stent coating to be used.

In this prospective, nonrandomized, open-label dose-finding study, 602 patients with angina pectoris or ischemia brought on by exercise received either a microporous bare-metal stent without a drug coating or a DES, coated with 0.5, 1.0, or 2.0% rapamycin solution. Use of multiple rapamycin-eluting stents at equal dosages was permitted, to cover long or multiple lesions. The study found that significant reductions were achieved both in the rate of angiographic in-segment restenosis (defined as ≥50%) at a median of 198 days (P = 0.024) and in the need for target-lesion revascularization at 1-year follow-up (P = 0.006) with increasing doses of rapamycin when compared with bare-metal stents.

The authors conclude that this DES system is safe and feasible, and that assigning patient-specific rapamycin doses aids the prevention of restenosis. A larger, randomized, trial is needed to investigate fully the efficacy of rapamycin-eluting stents.