Cath Lab Digest - February 2008 - (Page 8)

8 CLINICAL TRIAL UPDATE FEBRUARY 2008 continued from page 1 ENDEAVOR IV the surface of a red blood cell. Animal studies have indicated that this polymer is non-inflammatory, with a very favorable healing response. The polymer carrier is also extremely thin compared to the polymer carriers of the Cypher and the Taxus stents, only one micron in thickness after drug elution, which may contribute to its biocompatibility. The therapeutic agent is zotarolimus, a sirolimus analog which has equal anti-proliferative potency compared to sirolimus, but is slightly more lipophilic. This means that zotarolimus has a longer tissue residence time once it is eluted from the stent into the vessel wall. Zotarolimus from the Endeavor stent is eluted quickly over the first two weeks, with small amounts of drug retained in the tissue for slightly longer than a month. The rapid elution of the drug may be important in helping to explain rapid healing of the stent surface. The Endeavor drug-eluting stent system has been designed with safety in mind. It is our hope — but of course we need more clinical data to be conclusive — that this device will have safety properties similar to a bare-metal stent, while retaining clinical anti-restenosis efficacy similar to a first-generation drug-eluting stent. What was the ENDEAVOR IV trial design? ENDEAVOR IV was a large pivotal randomized clinical trial, conducted at 80 sites in the U.S., involving 1,548 patients with obstructive native coronary lesions. The patients were equally randomized to the Endeavor stent or Taxus paclitaxel-eluting stent. The primary endpoint of ENDEAVOR IV was target vessel failure, a composite endpoint consisting of cardiac death, myocardial infarction, and target vessel revascularization at nine months. The secondary endpoint was in-segment late loss, determined by angiographic follow up at eight months in a small subgroup of patients. ENDEAVOR IV New to the cath lab? Unsure of a particular term? A glossary is available on page 12. has been completed and the primary endpoint of target vessel failure at nine months was 6.6% for Endeavor versus 7.2% for Taxus. Endeavor clearly fulfilled its non-inferiority primary endpoint. Importantly, target lesion revascularization was also statistically indistinguishable between Endeavor and Taxus, especially if we focus on the 80% of patients who did not have angiographic follow up. The angiographic endpoint, in-segment late loss, was increased with Endeavor compared to Taxus, as was binary restenosis. Endeavor’s higher in-segment late loss at angiographic follow up sparked a great deal of discussion when you presented the trial data at TCT. This is complex and interesting issue. Angiographic results, like insegment late loss, are meant to be surrogate endpoints. Of course, what physicians care about most when we implant a bare-metal or drug-eluting stent is whether that patient is going to have a clinical recurrence at the treatment site that requires repeat revascularization. The best study endpoint to determine the need for repeat revascularization is target lesion revascularization. If you interpose systematic angiographic follow up into a study, it is common for revascularization events to occur at a higher rate. This phenomenon is called the “oculostenotic reflex,” which means that the presence of a follow-up angiogram influences clinical decision-making about whether the physician performs a repeat revascularization. Since there is a higher late loss and percent diameter stenosis at follow up with Endeavor stents compared with Taxus stents, the oculostenotic reflex is especially important, as physicians react disproportionately to Endeavor stents, which have more frequent intermediate stenoses that are clinically unimportant. In the ENDEAVOR IV trial, the 20% of patients with angiographic MI: myocardial infarction; TLR: target lesion revascularization; TVR: target vessel revascularization; MACE: major adverse cardiac events; TVF: target vessel failure

Table of Contents Feed for the Digital Edition of Cath Lab Digest - February 2008

Cath Lab Digest - February 2008 Bay Regional Medical Center ENDEAVOR IV: A Zotarolimus-Eluting Stent Versus a Paclitaxel-Eluting Stent in a Randomized Clinical Trial A 3D CT Vessel “Roadmap” Over Live Fluoroscopy for Chronic Total Occlusions Contents Clinical Editor’s Corner An Evaluation of Cath Lab Turnaround Time Commentary: An Evaluation of Cath Lab Turnaround Time Excerpts from Chapter 19. STEMI Interventions – Future Perspectives The Potential Clinical Utility of Intravascular Ultrasound Guidance in Patients Undergoing Percutaneous Coronary Intervention With Drug-Eluting Stents The Ten-Minute Interview with…Debbie Charlton, RN The Society of Invasive Cardiovascular Professionals (SICP) at Transcatheter Cardiovascular Therapeutics (TCT) 2007 The Cath Lab is a Business: Do You Have the Knowledge to Stay Afloat? Incidence and Predictors of Vascular Complications after Invasive Coronary Procedures: A Prospective Analysis Ask the Clinical Instructor: A Q&A Column for those New to the Cath Lab Volunteer Survey SICP* Section Meetings Calendar What Do You Think? CEU Education Center Clinical & Industry News Classifieds Advertisers Index

Cath Lab Digest - February 2008

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