• Late lumen loss at 6 months
  

• Procedural success
  
• Occurrence of acute (up to 48 hours), subacute (up to 30 days), and late thrombosis
  
• 30-day MACE rate
  
• Percent in-stent stenosis at 6 months
  
• Percent in-segment stenosis at 6 months
  
• In-stent late loss index at 6 months
  
• Angiographic binary in-stent stenosis rate at 6 months
  
• In-segment late loss index at 6 months
  
• Angiographic binary in-segment stenosis rate at 6 months
  
• Acute and cumulative MACE rate at 6 months
  
• Cumulative MACE rate after one year
  
• Cumulative MACE rate after three years
  
• Indication for premature follow-up
  
• Type of recurrence (Mehran-Classification)
  
• Target vessel failure
  

Background information:

Stent deployment for the treatment of coronary artery stenoses has evolved as the standard treatment in nearly all types of coronary lesions over the past two decades.The initial recurrence rate of bare stents in the range of 20 30 % in low risk stenoses has been further reduced by devices with passive coatings such as silicon carbide, heparin, phosphorylcholine, and carbon. The significant decline of in-stent restenoses (= ISR) to the order of 12 % was achieved by active coatings like the cell-cycle inhibitor sirolimus and to about 13.7 % by the cytotoxic paclitaxel. Taken into account the more than one million annual stent procedures performed worldwide even low recurrence rates will leave some hundred thousand repeat procedures annually. In the treatment of in-stent restenoses, however, approaches such as stand alone angioplasty with conventional balloons, the repeat use of bare stents, cutting balloon angioplasty, rotablation, and atherectomy have revealed unsatisfactory and often conflicting results. For brachytherapy the late loss was reported in the range from 0.22 +/- 0.84 mm to 0.73 +/- 0.79mm. Due to its disadvantages such as delayed endothelialization with ensuing late thrombosis cumulating in a 12-months cardiac event rate of up to 30% rising to 50% after five years, its decrease of benefit over time, and the cumbersome logistics at the sites and in the labs, brachytherapy is not considered as a valid approach of the future. Recently, the deployment of drug eluting stents into a restenotic device was associated with restenosis rates in the range from 4% to 30% suggesting some advantage over the aforementioned approaches. The wide range of the results and some late cardiac events still leave room for alternative methods such as the Paclitaxel-eluting PTCA balloon catheter.

Study Rationale The principle of the Paclitaxel-eluting PTCA balloon catheter is based on the antiproliferative mode of action of the compound, the latter being homogenously distributed along the entire length of the balloon and, hence, the vessel segment to be treated. This advantage is in particular relevant in comparison to drug eluting stents as are the lack of chronic mechanical alterations of the artery, the ease of access to the lesion, the obviation of adding another layer of metal to the lesion, and the presumably lower cost of the procedure. Data on the use of the Paclitaxel-eluting PTCA balloon catheter on the treatment of in-stent restenoses, however, are scant. In the animal model and according to unpublished results in humans, the proliferation induced by a Paclitaxel-eluting balloon catheter was significantly less compared to an uncoated balloon and to the Sirolimus-eluting Cypher™ stent.Therefore, it is prudent to compare the direct arterial application of Paclitaxel by means of the Paclitaxel-eluting PTCA balloon catheter versus the Paclitaxel-eluting Taxus™-stent as percutaneous transluminal treatment options of in-stent restenosis in human coronary arteries in a prospective randomized pilot study.