Five-Year Data From Cook Medical's Japan Postmarket Zilver PTX Registry Presented at CIRSE

September 22, 2018—Kimihiko Kichikawa, MD, presented 5-year follow-up data from a Japanese postmarket surveillance study of Cook Medical's Zilver PTX paclitaxel-eluting stent during the late-breaking trials session at the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) in Lisbon, Portugal.

The all-comers registry enrolled 904 patients with 1,080 lesions, in which 1,877 Zilver PTX stents were placed. Five-year data were collected for 411 of the enrolled patients. Notable among the baseline patient characteristics were higher patient age, more diabetics, and more renal failure compared to the Zilver PTX randomized controlled trial, which had narrower inclusion criteria. Given the real-world nature of the study, the lesions were also longer (14.6 ± 9.6 cm) and more complex, with higher rates of total occlusions and fewer patent runoff vessels, as well as a higher incidence of critical limb ischemia.  

Prof. Kichikawa showed a freedom from target lesion revascularization (TLR) rate of 74.2% in the registry, and clinical benefit (a composite endpoint including TLR, claudication, rest pain, change in Rutherford class by 2 or more, gangrene, ischemic ulcers, and amputation) was maintained in 68.2%. Clinical improvement was also maintained over time, with a 5-year average ankle-brachial index of 0.83 ± 0.18 (versus 0.63 ± 0.18 at baseline).

The study includes a number of subgroup analyses, of which the results in diabetic patients were presented at CIRSE. Of the 904 patients enrolled, 532 had diabetes. The freedom from TLR rate in this group was 72.2%, compared with 77% in nondiabetics.

The total stent fracture rate was 1.9%, with the majority having occurred in the first year (1.5%). Between years 1 and 3 and between years 3 and 5, the stent fracture rate was 0.8% in both intervals.

Summarizing the findings, Prof. Kichikawa concluded that the 5-year Japan postmarket surveillance study results are consistently good despite the all-comer study population's high incidence of diabetes, renal failure, long lesions, in-stent restenosis, limited runoff, and critical limb ischemia. Prof. Kichikawa is with the Department of Radiology at Nara Medical University Hospital in Kashihara, Japan.