CHICAGO — The Resolute Integrity zotarolimus-eluting stent demonstrated ongoing efficacy out to 2 years in a broad range of US patients, including those with small vessels.
Laura Mauri, MD, MSc, of the Brigham and Women’s Hospital in Boston, presented 2-year outcomes from the pivotal RESOLUTE US study at the American College of Cardiology’s 61st Scientific Sessions.
The RESOLUTE US program enrolled 1,402 patients from 128 US-based clinical trial sites. During the angioplasty procedure, each patient received a zotarolimus-eluting stent (Medtronic) ranging from 2.25 mm to 4 mm in either one or two lesions. Patients were then followed with clinical or angiographic follow-up. Nearly 99% completed 1-year follow-up and 97% completed 2-years of follow-up. At 2 years’ follow-up, the researchers obtained data from 1,359 of the enrolled participants.
Target lesion failure at 2 years — the primary endpoint of the study — was 7.3% in all patients studied.
“We broke this down by components,” Mauri said. “The target lesion failure was primarily comprised of target lesion revascularization, with rate a 4.3%, and less cardiac death, with a rate of 1.5%. Also, incremental rates of death and MI were low at 12 months, and remain low.”
Rate of stent thrombosis rate was 0.2% at 2 years, according to Mauri.
“Between years 1 and 2, there was only one additional stent thrombosis event,” she said.
Mauri also presented results of subgroup analyses, including those for patients with diabetes and those with 2.25-mm vessels.
“The most notable characteristic of the [RESOLUTE] US study population was that there was a high diabetes rate,” Mauri said. One-third of the participants had diabetes, and almost 10% were insulin dependent.
“In the diabetic cohort, the target lesion failure rate was 8.9%, the cardiac death rate was 2.1%, and the target vessel MI was 1.5%,” she said.
The target lesion failure rate among patients with small vessels was 8.2%, with a cardiac death rate of 3.4%.
“Out to 2 years, the target lesion failure rate was consistently low in all groups studied,” she said.
Mauri noted that the researchers included patients with up to two de novo lesions in native coronary arteries between 2.25 mm and 4 mm. Patients with acute MI within 72 hours were excluded.
Eligible patients were treated with clopidogrel for a minimum of 6 months.
“We found that, typical of the US population, it was common for them to be on antiplatelet therapy at 1 year,” Mauri said. “At 2 years, that rate was 67.2%.”
Previously presented 1-year results demonstrate low rates of target lesion failure (4.7%), clinically driven target lesion revascularization (2.8%) and definite/probable stent thrombosis (0.1%).
The RESOLUTE US study was designed to garner FDA approval for the Resolute Integrity stent. The stent was approved in February for the treatment of coronary artery disease, including patients with diabetes. The stent is also approved in Europe, Australia, New Zealand and several countries in Asia.
Mauri said the study is currently in long-term follow-up that will extend to 5 years. – by Rob Volansky
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Disclosure: Dr. Mauri is a consultant to and receives institutional grant support from Medtronic.