The efficacy of nanoscale poly[bis(trifluoroethoxy) phosphazene] (PTFEP) coatings in reducing thrombogenicity and late in-stent stenosis in a porcine coronary artery model.
OBJECTIVE
Previous experimental studies have demonstrated that poly[bis(trifluoroethoxy)phosphazene] (PTFEP) nanocoated stents have antithrombotic characteristics, reduce in-stent stenosis, prevent wall inflammation, and do not hamper endothelialization. This study was designed to validate these findings in a porcine coronary artery model.


METHODS
PTFEP-coated (n = 15) and bare stents (n= 13) were implanted in coronary arteries of 18 mini-pigs (4- and 12-week follow-up). Primary study endpoints were thrombogenicity and in-stent stenosis, secondary study endpoints were inflammatory response and re-endothelialization evaluated by quantitative angiography and light microscopy.


RESULTS
No thrombus deposition occurred on any stent. At 4 weeks follow-up, the bare stents (n = 4) had a significantly smaller neointimal area (1.93 vs. 3.20 mm(2), P = 0.009). At 12 weeks, PTFEP-coated stents (n = 11) had significantly superior results in almost all parameters: neointimal area (2.25 vs. 2.65 mm(2), P = 0.034), neointimal height (204.46 vs. 299.41 microm, P = 0.048), percentage stenosis (38.25 vs. 50.42%, P = 0.019), and inflammation score (0.12 vs. 0.30, P = 0.029). Complete re-endothelialization was seen in both stent types at both intervals.


CONCLUSIONS
At long-term follow-up, the superior results of PTFEP-coated stents were characterized by a noteworthy reduction of neointimal growth and inflammatory response.
Satzl
Stefanie
S
Department of Diagnostic Radiology, University of Heidelberg, Heidelberg, Germany.
Henn
Christina
C
Christoph
Patricia
P
Kurz
Patrick
P
Stampfl
Ulrike
U
Stampfl
Sibylle
S
Thomas
Florian
F
Radeleff
Boris
B
Berger
Irina
I
Grunze
Michael
M
Richter
Goetz M
GM
D000818:Animals; D020099:Coated Materials, Biocompatible; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000473:pathology; D023421:Models, Animal; D009943:Organophosphorus Compounds; D011108:Polymers; D011474:Prosthesis Design; D013193:Stainless Steel; D015607:Stents; D013552:Swine; D013556:Swine, Miniature; D013927:Thrombosis / Q000517:prevention & control*; D017539:Tunica Intima / Q000473:pathology; D014654:Vascular Patency
D020099:Coated Materials, Biocompatible; D009943:Organophosphorus Compounds; D011108:Polymers; D013193:Stainless Steel; C081660:poly(bis(trifluoroethoxy)phosphazene)