NEW YORK (Reuters Health) – A coronary stent incorporating a polytetrafluoroethylene membrane does not live up to expectations in the treatment of diseased aortocoronary saphenous vein grafts, investigators reports in the March issue of JACC: Cardiovascular Interventions.
Dr. Gregg W. Stone, with Columbia University Medical Center, New York, New York and colleagues point out that when saphenous vein grafts (SVGs) used for coronary artery bypass deteriorate, percutaneous intervention with bare metal stents improve outcomes, and distal protection devices can improve procedural safety. However, novel approaches are needed to improve the prognosis.
The JOSTENT is a double mesh stent with a PTFE membrane sandwiched between the two layers, currently available in the US on a humanitarian basis for the treatment of life-threatening coronary perforation, they note.
“Hypothetical benefits of elective use of the JOSTENT PTFE stent-graft in SVGs include reduced periprocedural myocardial infarction (MI) (by trapping potentially embolic degenerated atherosclerotic debris behind the PTFE membrane) and decreased restenosis (by serving as a barrier isolating the lumen from smooth muscle cell proliferation, migration, and extracellular matrix production arising from the media),” the authors explain.
They tested the device for this purpose in 243 patients with one or two discrete lesions in saphenous vein grafts who were randomized to JOSTENT or bare metal stent implantation. All participants then received aspirin and clopidogrel.
At 9 months, in-lesion binary restenosis was seen on angiography in 31.8% of lesions treated with the JOSTENT versus 28.4% of lesions treated with bare metal stent — a nonsignificant difference (p=0.63).
At that time point, the composite secondary end point of death, MI, or target vessel revascularization had occurred in 32.2% of patients treated with the JOSTENT versus 22.1% of those treated with a bare metal stent (hazard ratio: 1.54; p=0.08).
By 5 years, the corresponding cumulative rates were 68.3% vs. 51.8% (HR 1.59; p=0.007), Dr. Stone and colleagues found.
“The present trial underlines the dismal long-term prognosis of patients with diseased SVGs requiring PCI,” they conclude. “Polytetrafluoroethylene-covered stent-grafts have a greater failure rate when used for this application than BMS and, therefore, should be reserved for life-threatening perforations of the coronary vasculature.”
J Am Coll Cardiol Intv 2011;4:300-309.
