Thomas Zeller, Herz-Zentrum Bad Krozingen, Bad Krozingen, Germany, presented two-year results of the YUKON-BTK trial at the LINC conference in Leipzig, Germany.
YUKON-BTK, DESTINY and ACHILLES have shown superior one-year patency rates with drug-eluting stents compared to angioplasty/bare metal stents in below-the-knee lesions, Zeller noted. YUKON-BTK and ACHILLES investigated sirolimus-eluting stents (the polymer-free Translumina Yukon and the Cordis Cypher, respectively) and DESTINY assessed the performance of the Xience everolimus-eluting stent from Abbott. All the three trials showed statistically significant benefit (p<0.05) with the drug-eluting stents.
In YUKON-BTK, 161 patients were enrolled and randomised to either receive a sirolimus-eluting stent (82) or a bare metal stent (79). The trial enrolled not only critical limb ischaemia patients but also claudicants with moderate to severe claudication.
In the drug-eluting stent group, 12-month follow-up data were available for 62 patients, and, in the bare metal stent group, 12-month follow-up data were available for 63 patients. The one-year primary patency rate for the drug-eluting stent was 80.6% versus 55.6% for the bare metal stent.
At one year, there was also statistically significant improvement in the Rutherford-Becker classification with the sirolimus-eluting stent. A comparison of patients of each treatment group that achieved Rutherford class ≤2 (moderate or no claudication) at baseline, six and 12 months showed a significant difference in favour of the sirolimus-eluting stent, Zeller said. At baseline, the percentage of patients with Rutherford class ≤2 in the sirolimus-eluting stent group was 9.9% and for the bare metal stent group 15.5%; at six months, the rate for the drug-eluting stent was 71.4% and 66.1% for the bare metal stent; and at 12 months it was 78.8% for the sirolimus-eluting stent and 63.9% for the bare metal stent (p=0.04).
In terms of event-free survival at 12 months, including target lesion revascularisation, major and minor amputation, myocardial infarction and death (compared by Kaplan-Meier analysis with the use of the Mantel-Cox log-rank test), there was a trend towards better outcome for the sirolimus-eluting stents as compared to bare metal stents, but this was not statistically significant.
Results at two years
Zeller told delegates that, at two years, the amputation rate (major and minor) was 5.3% with the drug-eluting stent and 22.6% with the bare metal stent (p=0.04) in critical limb ischaemia patients. Differences in the rates of death, target lesion revascularisation, myocardial infarction and limb salvage were not statistically significant with a limb salvage rate of 97.4% for the drug-eluting stent cohort and 87.1% for the bare metal stent cohort.
In the intermittent claudication group, there was statistically significant difference in the rate of re-intervention with 7.9% of the drug-eluting stent patients and 25% of the bare metal device patients (p=0.04) requiring target lesion revascularisation.
The event-free survival rate was higher with the sirolimus-eluting stent (p=0.02) at two years.
Looking only at critical limb ischaemia patients, there was a trend in favour of the drug-eluting stent, but the difference was not statistically significant (p=0.07).
“Sirolimus- and everolimus-eluting stents achieve significantly higher and secondary patency rates at one year as compared to bare metal stents or angioplasty alone in the treatment of infrapopliteal lesions,” Zeller said. “Sirolimus-eluting stents improve quality of life in claudicants with predominantly focal proximal infrapopliteal disease.”
In the long run, Zeller said, the superior patency of drug-eluting stents may also improve event-free survival particularly in patients with critical limb ischaemia with Rutherford classes 5 and 6 and with an appropriate life expectancy.