Objectives: The long-term clinical outcome of covered stents in the percutaneous treatment of diseased saphenous vein graft (SVG) has been disappointing. The single self-expanding polytetrafluoroethylene (PTFE)-covered Symbiot stent with a unique profile may present advantages that translate into superior long-term clinical outcomes. This study evaluated the safety, effectiveness and clinical outcome of the Symbiot covered stent system (Boston Scientific, Natick, Mass.) and FilterWire EX (Boston Scientific, Natick, Mass.) versus bare metal stents (BMS) in SVG intervention.
Methods and results: Between January 2003 and August 2005, 90 patients with degenerative SVG lesions were prospectively randomized at 6 study sites to Symbiot implantation (n = 30), BMS with FilterWire as embolic protection device (EPD, n = 30), or BMS without EPD (control group, n = 30). The primary end point was reduction in peri-procedural cardiac enzyme rise. The major secondary end points were in-hospital, 6-month and long-term target vessel failure rates, defined as the cumulative of death, myocardial infarction and clinically driven target lesion revascularization. There was no significant reduction in median [IQR] post-procedural troponin-I rise in the Symbiot group compared to the FilterWire or the control group (0.08 [0-1.40] microg/l; 0.06 [0-0.28] microg/l; and 0.04 [0-0.31] microg/l, P = 0.58). At 7.4 +/- 1.3 (mean +/- SD) years, there were numerically less deaths in the Symbiot group, although this did not reach statistical significance (P = 0.20). There was no significant difference in TVF-free survival between the treatment groups (P = 0.98).
Conclusion: This study failed to show a procedural or long-term clinical advantage for the Symbiot PTFE-covered stent in the treatment of degenerated SVG.