• Late lumen loss at 6 months [ Time Frame: 6 month ] [ Designated as safety issue: No ]
  

• Procedural success [ Time Frame: during procedure ] [ Designated as safety issue: Yes ]
  
• 30-day MACE rate [ Time Frame: 30 days ] [ Designated as safety issue: Yes ]
  
• Percent stenosis at 6 months [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  
• Binary restenosis rate at 6 months [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  
• Late loss index at 6 months [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  
• Cumulative MACE rate at 6 months [ Time Frame: 6 months ] [ Designated as safety issue: Yes ]
  
• Cumulative MACE rate at 1 year [ Time Frame: 1 year ] [ Designated as safety issue: Yes ]
  
• Cumulative MACE rate at 3 years [ Time Frame: 3 years ] [ Designated as safety issue: Yes ]
  

Device: Drug Eluting Balloon
PCI of small vessels

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.

In the percutaneous transluminal treatment of stenotic coronary arteries with diameters below 3 mm, however, none of the currently available methods, namely balloon angioplasty with conventional balloons (POBA) and deployment of non-drug eluting stents have shown acceptable results for the various reasons inherent to these approaches. Although some studies showed POBA and the deployment of bare stents to be equally effective with respect to restenosis, in a recently published meta-analysis of eleven trials the restenosis rates were as high as 25.8 % for POBA and 34.2 % for bare stents, respectively.

Brachytherapy initially demonstrated encouraging results. However, due to its disadvantages such as delayed endothelialization, the risk associated with additional stenting, the cumbersome logistics at the sites and in the labs, brachytherapy is not considered as a valid approach. Data with the Sirolimus-eluting Cypher™ stent in vessels averaging 2.60 ± 0.54 mm in diameter showed the benefit of this cytostatic drug in this indication. However, this approach introduces a layer of metal to the per se small vessel and, thus, reduces the vascular lumen.

Study Rationale:

Since none of the above mentioned options for the percutaneous treatment of small vessel coronary artery stenoses seems to be universally recommendable the Paclitaxel-eluting PTCA balloon catheter has to be considered as an alternative. The possible advantages over either the uncoated balloon or bare stent include the antiproliferative mode of action of the compound. In comparison to the drug eluting stents (DES) the homogenous distribution of the compound along the target vessel segment, the lack of chronic mechanical alteration of the artery and the ease of access to the lesion would favor the Paclitaxel-eluting balloon.

However, there are no data available on the use of the drug eluting balloons in small vessel disease and the information on the other indication evaluated to date, the treatment of in-stent restenosis is limited. In the latter indication, 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, the Paclitaxel-coated Taxus™ stent, and to the Sirolimus-eluting Cypher™ stent. Therefore, it is prudent to test the Paclitaxel-eluting PTCA balloon catheter as an alternative approach for the percutaneous transluminal treatment of small vessel coronary artery lesions.

Since none of the alternative methods has unequivocally shown its superiority over the other, none of them may serve as the golden standard and, i.e., for direct comparison. Consequently, as the initial step conducting a single arm study with the Paclitaxel-eluting balloon is suggested with historic data serving for comparison. Once these results will have been obtained a prospective randomized trial shall be discussed.