Peripheral paclitaxel-eluting stent showed superior patency, clinical benefit at 5 years

Use of a paclitaxel-eluting stent to treat lesions in the superficial femoral artery was associated with superior patency, clinical benefit and freedom from target lesion revascularization at 5 years compared with standard care, according to data presented at VIVA 14.

The peripheral paclitaxel-eluting stent (PES; Zilver PTX, Cook Medical) also showed at 1 year similar clinical results in a postmarket surveillance study as were observed in randomized controlled trials, despite more challenging lesions, according to a separate presentation at the conference.

Five-year results

Michael D. Dake

In the Zilver PTX randomized controlled trial, Michael D. Dake, MD, the Thelma and Henry Doelger professor of cardiovascular surgery at Stanford University School of Medicine, and colleagues compared the safety and efficacy of the peripheral PES vs. balloon angioplasty and bare-metal stenting. The study included 479 patients with de novo or restenotic superficial femoral artery lesions.

These results represent the first known 5-year outcomes for the peripheral PES, Dake said at a press conference.

Compared with standard care, all of whom received balloon angioplasty and some of whom received a provisional BMS, patients who received the peripheral PES had a superior rate of freedom from TLR at 5 years (83.1% vs. 67.6%; P<.01), which represents a 48% reduction in reinterventions, according to Dake. The 83.1% figure “is the number that will be compared to in the future,” he said.

The peripheral PES group also had a superior 5-year patency rate compared with the standard care group (66.4% vs. 43.4%; P<.01), which represents a 41% reduction in restenosis. Patency criteria were “much more conservative” than in most studies, Dake said.

As time went on, the curves diverged, although the PES had used up its paclitaxel by 1 year. In the long term, “I just think we are seeing the difference between a balloon and a stent,” he said.

In clinical benefit, defined as freedom from persistent/worsening claudication, rest pain, ulcer or tissue loss, the peripheral PES group also had superior results compared with the standard care group at 5 years (79.8% vs. 59.3%; P<.01), according to results presented.

Patients in the study who failed balloon angioplasty (n=120) were randomly assigned to a provisional peripheral PES or a provisional BMS. Among those patients, the PES group had superior patency at 5 years (72.4% vs. 53%; P=.03), Dake said.

“These results for the Zilver PTX stent provide important insights for long-term outcomes for endovascular treatment,” he said.

Postmarket consistency

In the Zilver PTX Japan postmarket surveillance trial, researchers enrolled the first 907 patients in Japan treated with the peripheral PES after the device was approved in that country. They evaluated freedom from TLR and patency at 1 year, and compared results in lesions comparable to those seen in the randomized controlled trial (≤14 cm, no in-stent restenosis) vs. more complex lesions.

Hiroyoshi Yokoi

Compared with patients in the previous randomized and single-arm studies, patients in the postmarket surveillance study had more renal disease, longer lesions, more in-stent restenosis and fewer patent runoff vessels (P<.01 for all), Hiroyoshi Yokoi, MD, from Fukuoka Sanno Hospital in Fukuoka, Japan, said at the press conference.

In the Zilver PTX Japan postmarket surveillance population, there were 378 lesions comparable to those in previous trials (mean lesion length, 7.4 cm) and 703 more complex lesions (mean lesion length, 18.6 cm; 29% in-stent restenosis), Yokoi said.

At 1 year, the rate of freedom from TLR in the Zilver PTX Japan postmarket surveillance participants was 91.4%, with a rate of 96.7% for lesions comparable to those in previous trials and 88.3% for more complex lesions, he said. The rate is similar to the 91.6% in the randomized clinical trial and the 89.5% in the single-arm study, he said.

Approximately 60% of patients underwent duplex ultrasound to assess patency at 1 year. Among those patients, primary patency was 84.8% overall, 91% for lesions comparable to those in previous trials and 81% for more complex lesions, according to Yokoi. He said that rate is similar to the 84.4% in the randomized clinical trial and the 82.8% in the single-arm study.

“The Japan [postmarket surveillance] results through 1 year confirm the benefit of the Zilver PTX technology, including favorable results in more complex lesions,” Yokoi said. “Consistency across studies provides added assurance of the performance of the Zilver PTX drug-eluting stent.” – by Erik Swain

For more information:

Dake MD. Late-Breaking Clinical Trials.

Yokoi H. Late-Breaking Clinical Trials. Both presented at: VIVA 14; Nov. 4-7, 2014; Las Vegas.

Disclosure: Dake and Yokoi report serving as consultants for Cook Medical.