A post-market surveillance study of the Zilver PTX drug-eluting stent (Cook Medical) conducted in Japan has shown positive results with the device in the treatment of femoropopliteal lesions. According to the investigators, the results “confirm the benefit of the Zilver PTX technology”. The 12-month results, which were presented at the EuroPCR congress (20–23 May 2014, Paris, France), show no safety concerns and no increased thrombosis with the device.
Hiroyoshi Yokoi, Department of Cardiovascular Medicine, Fukuoka Sanno Hospital, Fukuoka, Japan, who presented the results on behalf of the investigators, explained that the Zilver PTX clinical programme included pre-market studies (a randomised controlled trial and a single-arm study) and post-market studies such as the Japan Post-market Surveillance (PMS) study of 907 patients.
Yokoi said that, in comparison to the pre-market studies, the Japan PMS study treated more complex patients and lesions as it was all “all-comers study” with no exclusion criteria used to eliminate patients from enrolment. “The Japan PMS patients were older and had a higher prevalence of diabetes and renal disease,” he said. “In addition, the lesions were more complex—they were longer, with more in-stent restenosis and fewer patent runoff vessels—and patients had significantly greater incidence of critical limb ischaemia, twice the incidence reported in the pre-market studies.”
At EuroPCR, he presented 12-month follow-up results that were available for 802 patients. In 58% of them, he said, patency was assessed by ultrasound if this was the standard of care.
He told delegates that freedom from target lesion revascularisation was 97.3% at six months and 91.4% at 12 months, similar to the rates seen in both pre-market studies, and that the rate of thrombosis/occlusion was 3.2% at 12 months.
“The 12-month thrombosis/occlusion rate from the Japan PMS was low and similar to the rates seen in the ZILVER PTX randomised controlled trial (1.9%) and the single-arm study (2.7%). It is also similar to the rates seen with the Zilver bare metal stent in the randomised controlled trial (3.6%) and to bare metal stent periprocedural rates in the literature (2–5%),” he stated.
The primary patency rate as assessed by duplex ultrasound (n=469) was 84.4% at 12 months, and this rate was similar to the rates seen in both pre-market studies.
Yokoi said that the Japan PMS study results were positive and confirmed the benefit of this paclitaxel-eluting technology.
“There is a large amount of clinical data available for Zilver PTX, ranging from carefully controlled level I evidence to large, global, real-world experience. As expected, the patient population and lesion characteristics become more challenging in real-world, all-comer studies. The consistency seen across studies provides added assurance of the performance of the Zilver PTX drug-eluting stent,” he concluded.