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Drug Eluting Stents:. Looking Forward Janine Lane Director Clinical Communication and Education Medtronic Vascular. Cobalt Alloy Modular stent Strut thickness 0.0036’’. Delivery based on discrete, secure Technology. Zotarolimus (Sirolimus analogue) 10 g/mm stent dosage.
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Drug Eluting Stents: Looking Forward Janine Lane Director Clinical Communication and Education Medtronic Vascular
Cobalt Alloy Modular stent Strut thickness 0.0036’’ Delivery basedon discrete, secure Technology Zotarolimus (Sirolimus analogue) 10 g/mm stent dosage BiocompatiblePC Technology (phosphorylcholinepolymer) Components of the Endeavor Stent
Lessons Learned • Antiproliferative drugs consistently reduce need for repeat intervention • Current drug eluting stents are associated with varied angiographic results • Perception of the cost benefit of drug eluting stents is not uniform
Unanswered Questions • Impact of current drug eluting stents on long-term safety? • Stent Thrombosis • Myocardial Infarction • Death • Ideal length of dual anti-platelet therapy?
Stent Thrombosis Factors to Consider • The polymer • Inflammatory • Thrombogenic • The drug • Delayed Endothelization • Late incomplete apposition • The patient • (more complex lesions =more thrombogenic milieu) = increased necessity for prolonged dual antiplatelet regimens
Stent thrombosis Rates According to Select Patient Characteristics *AntiplateletTherapyDiscontinuation PriorBrachy RenalFailure Bifurcations ULM Diabetes UA *Premature discontinuation From Milan/Sieburg Experience ACC 05.
Late Stent thrombosis After Anti-platelet Discontinuation CYPHER TAXUS 335 343 375 442 Usually associated with minor surgical procedures 0 100 200 300 400 500 Day McFadden EP et al. Lancet 2004; 364:1519–21
Aspirin Alone ≥1 antiplatelet agent Dual antiplatelet therapy Other agents (i.e. PLAVIX) At-Risk Patient Noncompliance Adherence to Antiplatelet Medication In at-risk patients from Western Europe over 24 months: 78% 62% Percent of Population 27% 11% Bhatt DL et al. JAMA 2006; 295(2):180-188
Unanswered Questions • Long term benefits (health care economics) • Stent design itself: • Elution characteristics • Ideal drug or drugs • Ideal delivery mechanism • Patient responses: • healing times of complex disease states • why current drug eluting stents sometimes fail • Can we improve safety while maintaining aggressive neointimal suppression
Diabetics Multi-Vessel Disease Clinically unmet needs in the DES era Smaller Diameter Vessels Diffuse Disease Long Lesions Bifurcation Lesions Left Main AMI Unmet Clinical Needs
Extracellular Matrix Reabsorption Thrombosis Smooth Muscle Cell Migration/Proliferation Extracellular Matrix Production (% Response) Elution Duration Inflammation Inflammation 14 3 90 440 1000 Drug In Tissue Unmet Clinical NeedsExtended Drug Exposure
Potential Solutions • One new drug eluting stent: • Multiple/combination drugs • Different delivery mechanism • Choice of drug eluting stents from one supplier • Indication specific drug eluting stents • One drug eluting stent with different versions
Next Generation DES Pipeline • Endeavor Controlled Response (CR) • Novel, Medtronic designed polymer coating • Tunable elution kinetics to match the breadth of healing needs in complex lesions • Capability to deliver multiple drugs
Single De Novo Native Coronary Artery Lesions Stent Diameters: 2.5, 3.0, 3.5mm Stent Lengths: 18, 24, 30mm (8/9mm bailout) Lesion Length: 14-27mm Drug Dose: 1.6 g/mm2 stent surface area Pre-dilatation required Medtronic RESOLUTE Clinical Trial 100 Patients (includes 30 PK Sub-Study Patients) 12 Sites (New Zealand and Australia) Endeavor CR Stent Clinical/MACE 9mo 30d 6mo 12mo 2yr 3yr 4 yr 5 yr Angio/IVUS (all patients) Primary Endpoint: Late lumen loss (in-stent) at 9 mo Secondary Endpoints: 1.MACE rate at 30 day and 6, 9, 12 mo 2. Acute success (device, lesion, procedure) 3. Angiographic parameters at 9 mo (%DS, LL, LL index, ABR, MLD) 4. TVF at 9 mo 5. Clinically driven TLR at 9 mo 6. Neointimal hyperplastic volume and percent volume obstruction (%VO) at 9 mo 7. PK Sub-Study Pharmacokinetic parameters (Cmax, Tmax, AUC, CL corresponding to AUC)
Conclusion • Many more questions than answers • Durability and safety • Medtronic is assessing the theory of delayed healing with the Endeavor CR program