Optimal Stent Expansion and Optimization Non-Compliant Balloons Optimal Stent Expansion and Optimization

Non-compliant balloons Despite advances in stent technology and implantation techniques, both acute and long‐term complications still occur Stent underexpansion has been defined as a major risk factor for both of these adverse events. Thus, stent optimization after deployment is crucial Post Dilatation has been recommended to overcome these complications and provide optimal stent expansion in PCI Tasal, et al Journal of Interventional Cardiology; Vol 26, No. 4, 2013

Pre-dilatation for challenging lesions Pre-dilatation may be appropriate in treatment of complex lesions Calcified Lesions CTO’s, Angulated Lesions B2/C Lesions Bifurcations Lesions with significant calcification may be difficult to expand Pre-dilatation minimizes the risk of inadequate stent expansion Kissing balloon technique (KBT) is an important part of stent optimization, used in bifurcation lesions1 EBC recommends the use of NC Balloons to prevent over-dilatation during kissing inflations2 Initial angioplasty with small diameter balloon, followed by larger sized balloon catheters or stents Pre-dilatation may limit stent length and reduce complications3 1 Sgueglia , et.al. JACC CI 2012 2. Hildick-Smith et al. EuroIntervention 2010;6:34-38 3. Kandzari, CCI 2010

Post Dilatation for Optimal Expansion Post-Dilatation is important for optimization of stent apposition to the vessel wall1 DES studies have shown that stent under expansion is common in initial stent deployment and a strong predictor of stent thrombosis and target vessel revascularization (TVR)2 “Of 256 patients with IVUS studies [...], only 29% achieved optimum stent deployment with the stent delivery system.”4 “Inadequate stent expansion results in abnormal shear stress that might be associated with stent thrombosis.”5 Full stent apposition is key to achieving positive, long-term outcomes 2,3 1 Parikh, M. TCT 2009 2 Brodie. J Interv Cardiol. 2006 3 Fitzgerald & Leon. Netherlands Heart Journal, Volume 14, Number 9, September 2006 4 Brodie et al, CCI 2003 5 Fuji et al, Journal of the American College of Cardiology 2005

Stent Malapposition – Contributing Factors You cannot determine if a stent is well apposed based on angiography alone. Stent malapposition contributing factors include: Low pressure stent deployment Long lesions requiring multiple stents Lesions with heavy calcification Treatment of diffuse in-stent restenosis Lesions with severe stenosis Bifurcation lesions with side-branch stenting Romagnoli JACC CI 2008

Stent Deployment Optimization High pressure NC Balloons are used to ensure a uniform distribution of wall stress, maximal stent expansion and stent strut apposition. Stent Optimization Goals3: NC Balloon Attributes Complete stent apposition to the vessel wall Adequate stent expansion Full lesion coverage without edge dissection High pressure, non-compliant balloons should be used post stent-deployment1 The non-compliant balloon used is shorter and usually one-quarter size larger2 Stent optimization aims at preventing incomplete stent expansion and stent malapposition to the vessel wall after the intervention. Post-dilatation with a non-compliant (NC) balloon as opposed to a stent-mounted semicompliant balloon theoretically assures a more uniform distribution of wall stress and stent expansion and axial stent symmetry indices improve DES – NC balloons help ensure complete apposition Bifurcations – NC balloons are recommended for final KBT and post dilatation (POT) Stent optimizaiton means ensuring good apposition of stent struts to the vessel wall, such that the stent struts are not surrounded by lumen, adequate stent expansion to obtain MSA at least > 6.5 mm2 for BMSs and > 5.0 mm2 for DESs or MSA > 90% of the distal reference lumen CSA, and lack of major dissections, intramural hematomas, and geographic misses. (Yoon & Hur. Korean J Intern Med 2012) Risk of “dog bone”/ edge effect with SC balloon at high pressure NC balloon at high pressure Protruding Apposed to the intima but not embedded Malapposed No contact to the intima 1 Romagnoli et al, J.Am Coll Cardio Intv. 2008 2 Brodie. J Interven Cardiol. 2006 3 Yoon & Hur. Korean J Intern Med 2012 1Di Mario C, et al, 2008

Post Dilatation Considerations Increased procedure cost and operational inefficiencies1,2 Limits cath lab capacity and through out. Use up more resources during longer procedure time Edge Dissection/ Perforation1,2 A tear created within the tissue wall. Requires another stent and drug therapy or CABG for more severe cases Longitudinal Stent Deformation3 Balloon may get trapped. If it can not be removed may require surgery. Increased intimal damage4 Dilating the vessel more often creates more vessel trauma. Distal Embolization5 a distal filling defect with an abrupt ‘cut-off’ in one of the peripheral coronary branches of the infarct related artery, distal to the angioplasty site. Frobert PLoS ONE 2013 1,2 J. Ormiston, CRT2013)3 sciencedirect.com Intimal hyperplasia4 J. P. S. Henriques, et al European Heart Journal (2002)5

NC Balloon Characteristics NC Balloons offer the best opportunity for good stent/vessel apposition due to high pressure & low compliance1 Recommended in the stent IFUs Important NC Balloon characteristics include2: Strength/from Durable Material Incorporation of these important balloon characteristics may help to reduce the identified risks sometimes associated with Post-Dilatation High RBP (up to 20atm) Pushable and Trackable Low Radial Growth Rate Low Longitudinal Growth Rate 1 Brodie. J Interven Cardiol. 2006, 2 Stone, TCT2013

Clinical Outcomes - Post-Dilatation after Stent In this study, Post-dilatation was performed safely in patients with AMI The data show that it may reduce risk of TVR and ST without increasing adverse cardiovascular events or mortality P = 0.49 P = 0.04 P = 0.04 P = 0.10 Events at 6 month follow up Tasal, et al Journal of Interventional Cardiology; Vol 26, No. 4, 2013

Careful vessel preparation can influence TLF The RESOLUTE Japan Trial was conducted using careful lesion preparation and extensive imaging. RESOLUTE Japan TLF to 3 Yrs 4 8 12 16 20 24 28 32 36 2 6 10 Target Lesion Failure (%) 4.0% RESOLUTE Japan Lesion Prep/Imaging IVUS Use (%) 99 Pre-Dilation Pressure Range (min, max) 6.00, 24.00 Post-Dilatation (%) 78 The Japan Clinical Trial was conducted with extensive lesion preparation and extensive imaging, similar to what is recommended in the ABSORB Trials Months 100 96 95 94 93 91 Number at risk The 3-year TLF rate from RESOLUTE Japan was 4.0% No TLF creep was seen in the RESOLUTE Japan trial

Discussion Dilatation with a noncompliant balloon (NC) after stent deployment at 6 months has shown: to provide optimal stent expansion, reduced target vessel revascularization (TVR), provide better angiographic results and Improve clinical outcomes in elective PCI