WASHINGTON — A stent dedicated to difficult-to-treat bifurcated lesions appears to significantly reduce restenosis and in-stent late loss, according to results presented at a symposium sponsored by the Cardiovascular Research Foundation.
Dr. Eberhard Grube, chief of cardiology and angiology at the Siegburg (Germany) Heart Center, reported on the 6-month results of Axxess Plus, a registry designed to evaluate the safety and efficacy of the Axxess Plus stent in de novo coronary bifurcation lesions and to determine the best treatment strategy in branch vessels.
Axxess Plus is made from a self-expanding nickel-titanium (nitinol) alloy, which is coated with a bioabsorbable polylactic acid polymer that elutes biolimus A9, a sirolimus analogue. The device is manufactured by Devax Inc. (Irvine, Calif).
So far, the registry has enrolled 139 patients from 13 centers in the United States and abroad. Dr. Grube, principal investigator in the trial, reported on the first 125 patients. Data from Axxess Plus will be used to support applications for regulatory approval in Europe and the United States, according to Devax.
About 15%–20% of the 2.5 million percutaneous coronary interventions worldwide involve lesions at a bifurcation, but treating such lesions is extremely difficult, said Dr. Grube.
With Axxess Plus, the stent is implanted with the appropriate shape to treat the bifurcation, then more stents can be added as needed to cover the lesion, said Dr. Grube.
The registry accepts patients with any and all bifurcations. The primary end point is in-stent late loss at 6 months. With angiographic follow-up on 93% of the patients with Axxess Plus stents, the late loss was 0.11 mm, plus or minus 0.62 mm, compared with 0.46 mm, plus or minus 0.51 mm, for the control group of patients who had previously received an Axxess bare metal stent, a statistically significant difference.
Just over 5% of patients had binary restenosis in the parent vessel, as measured by qualitative coronary angiography, said Dr. Grube.
Patients with side branch involvement received no treatment, percutaneous transcatheter coronary angioplasty (PTCA), or a stent. The choice of procedure was left to the investigator's discretion, Dr. Grube said.
Across those three groups, the mean late loss was 0.24 mm for the 26 patients who received no treatment, 0.19 mm for the PTCA group (40 patients), and 0.21 mm for the stent group (70 patients).
The in-segment restenosis rate was 12% for the no treatment group, 25% for the PTCA group, and 7.9% for the Axxess Plus group. “The lesion success with PTCA was clearly lower than leaving it alone or using a stent,” noted Dr. Grube.