Johannes Lammer, Vienna, Austria, principal investigator of the STRIDES trial sponsored by Abbott Vascular, presented the six- and 12-month results at CIRSE 2009, September 19-23, Lisbon, Portugal.
“Dynalink E is a slow-eluting, self-expanding, drug-eluting stent releasing approximately 80% of the drug over three months. There was sustained clinical benefit with improvement in Rutherford-Becker clinical category in 80% of patients after 12 months and there were no observed stent fractures after 12 months.
“A retrospective comparison to the historical VIENNA Absolute trial suggested improved patency rate of DYNALINK-E vs. bare metal at six months. However, the improved patency rate was not sustained at 12 months,” he said.
This follows the results of the SIROCCO II study which showed that drug-eluting stents have delayed, but failed to conquer restenosis in the superficial femoral artery.
SIROlimus Coated Cordis SMART Nitinol Self-expandable stent for the Treatment of Obstructive Superficial Femoral Artery Disease (SIROCCO II) confirmed the short term efficacy of the slower release formulation identified in SIROCCO I. It found good outcomes in the bare SMART stent arm of the trial with an overall 6 month angiographic pooled restenosis rate of 11.6% (n=43) and an 18 month rate of 22.2% (n=45). However, slower eluting data pooled from SIROCCO I and II resulted in an early statistically significant difference in the primary endpoint (mean stent diameter), Showed that this advantage was lost by 18 months.
The STRIDES trial enroled 104 patients at 14 European sites, with a primary endpoint of in-stent restenosis (a measure of vessel re-narrowing) in the superficial femoral artery at six months. Secondary endpoints include angiographic (X-ray) measurements of the change in vessel lumen diameter between the time immediately following stent placement and at 12 months, restenosis at 12 months, as well as five-year clinical follow-up to track resolution of PAD symptoms, limb preservation and patient survival.
The STRIDES trial enroled complex patients, including 17% with critical limb ischaemia,45% with total limb occlusions, 39% with length greater than 10cm, 9.4% with restenosis and 78% with TASC C 2000 classification.
“This is a first-in-man evaluation of Dynalink-E in the superficial femoral arteries and the purpose of the first-in-human STRIDES trial was to evaluate the safety and efficacy of an everolimus-eluting nitinol stent for the treatment of superficial femoral and proximal popliteal arterial occlusive disease,” Lammer said.
“The superior patency rate of the drug-eluting Dynalink-E stent within the first six months may be beneficial to patients with critical limb ischaemia to improve early wound healing,” he said.
Experts find that while drug-eluting stents approved for use today were designed with the coronary arteries in mind, superficial femoral arteries in the leg present a different kind of anatomy that can be challenging to treat because re-obstruction of the vessel is a major concern. The STRIDES trial is evaluating the use of a self-expanding stent system specifically designed to withstand normal leg movement, combined with the anti-proliferative drug everolimus, as a longer-term treatment alternative for patients with superficial femoral artery disease.