New clinical data presented in San Francisco, USA, show strong and sustained efficacy and safety of the Resolute zotarolimus-eluting coronary stent from Medtronic, in long-term patient follow-up.
The single-arm RESOLUTE trial (n=129) demonstrates a low, 1.6% cumulative rate of target lesion revascularisation (TLR) – or repeat procedures to treat the previously stented portion of the vessel – with no new TLRs between two and three years of follow-up. Cumulative rates of other clinical events also remained low, with no new myocardial infarctions or cardiac deaths after two years. In addition, the rate of stent thrombosis – the formation of rare but dangerous blood clots within the stent – remained at zero, despite only 36.6% of patients being maintained on dual antiplatelet therapy (aspirin and clopidogrel) at three years.
The three-year results of RESOLUTE were released at Transcatheter Cardiovascular Therapeutics (TCT) 2009. “RESOLUTE included patients with a high degree of complexity for an initial clinical trial of a new drug-eluting stent,” said principal investigator Ian Meredith of Monash Medical Center in Australia. “Their remarkable outcomes at three years suggest that the Resolute drug-eluting stent (DES) offers a durable combination of long-term safety and efficacy that bodes well for the broad range of patients we see in the challenging environment of standard clinical practice.”
The average lesion length of RESOLUTE patients was 15.5mm, and 82% of the subjects had challenging B2/C lesions. In addition, 46% had a prior myocardial infarction, and 18% had a prior percutaneous coronary intervention; 18% had diabetes; 30% had unstable angina; and 70% had a history of smoking.
The Resolute DES features Medtronic’s proprietary BioLinx polymer system, which was designed to minimise inflammation, reduce thrombotic risk and to enable rapid, complete and functional healing of the treated vessel. The BioLinx system has demonstrated the same biocompatibility requirements as the phosphorylcholine (PC) polymer used in the company’s Endeavor zotarolimus-eluting stent. Compared to the PC polymer, the BioLinx system is designed to extend the duration of drug exposure in the vessel – an elution profile of potential relevance to patients whom physicians consider to be at highest risk of needing a repeat procedure. Developed by Medtronic scientists, it is the first polymer created specifically for use on a DES.
The Resolute DES is commercially available in more than 100 countries outside the United States, where it is limited to investigational use in an FDA-approved clinical trial called RESOLUTE US. Medtronic is collaborating with physicians around the world to complete a global clinical trial programme that will enrol more than 7,500 patients worldwide, with more than 6,300 patients receiving a Resolute DES. Enrolment for RESOLUTE US is now complete.
RESOLUTE US (n=1,399) is a large, prospective, multicentre, controlled single-arm trial with a primary endpoint of target lesion failure (TLF) at 12 months. TLF is defined as cardiac death, target vessel myocardial infarction (Q-wave or non-Q-wave), or clinically-driven TLR by percutaneous or surgical methods. The resulting data will be used to seek FDA approval, which Medtronic expects to receive in 2012.