Cath Lab Digest - March 2008 - (Page 40)

40 CLINICAL UPDATE MARCH 2008 FFR-guided strategy resulted in deployment of fewer stents, lower cost and improved outcomes compared to an angiographic-guided approach.32 This approach is currently being prospectively investigated in a randomized trial.33 IVUS can also be used in the assessment of moderate coronary lesions. In one study of 51 epicardial lesions evaluated by both IVUS and FFR, a minimal lumen cross-sectional area (MLA) of 60% area stenosis predicted a hemodynamically significant lesion compared to FFR.34 In another study of 53 lesions, a MLA of <4 mm2 and a minimal lumen diameter 3.5 mm in diameter.36 A cohort of 233 patients who underwent single-vessel PCI with DES in arteries >3.5 mm had similar outcomes as 233 propensity-matched patients who received BMS. At oneyear follow up, major adverse cardiac events (MACE) occurred in 8.5% of the patients with DES and 7.7% of the patients with BMS (p = 0.80). Thus, patients with large vessels (>3.5 mm) represent a population with a low risk for MACE using BMS. These findings are in line with subgroup analysis of the TAXUS-IV trial, where the benefit of DES over BMS for restenosis was limited to vessels 0.90 after BMS deployment is associated with a low (<6%) MACE38 and conversely, FFR 20%) MACE. A recent analysis of that registry indicated that baseline FFR and stent diameter could predict optimal post stent FFR and outcomes, suggesting that both baseline FFR and expected stent diameter could be used to guide the choice of BMS versus DES.39 3. How can stent deployment be optimized? Invasive imaging tools may be very helpful in optimizing stent deployment by reducing stent thrombosis, BMS restenosis, and possibly identifying lesions that are high risk for peri-procedural distal embolization. With either BMS or DES, the most important procedure-related risks for stent thrombosis are smaller final lumen dimensions due to stent under-expansion and/or malapposition, increased stent length, persistent slow coronary flow, multiple stents, positive remodeling, dissections, geographic miss, and late stent malapposition due to thrombus resolution.2,40–43 Post-PCI IVUS can often detect malapposition, under-expansion, residual stenosis, dissections, and geographic miss. Early studies with IVUS showed that 40–70% of angiographically well-deployed stents have under-expanded regions when examined by IVUS.44-46 These findings led to the deployment of stents at higher inflation pressure to increase stent expansion and apposition.47 However, even in the era of stent deployment at high pressure, IVUS-guided trials suggest that incomplete strut apposition occurs in 4% to 22% of PCIs.48 Achieving adequate stent expansion with large post stent minimal luminal areas also reduce the risk of restenosis with BMS. While the results of randomized studies of IVUS-guided versus angiographicguided BMS deployment are mixed, they favor IVUS guidance. In the Can Routine Ultrasound Influence Stent Expansion (CRUISE) study, IVUS guidance led to less target vessel revascularization (8.5% versus 15.2%, p < 0.05). In the Direct Stenting vs Optimal Angioplasty (DIPOL) study, IVUS-guidance caused the operator to post-dilate the stent in 39.7% of procedures and MACE occurred less frequently with IVUS guidance (7.3% versus 16.2%, p 7 mm2, (b) minimal stent CSA > 80% of average proximal and distal reference segments, and (c) complete stent apposition to vessel wall.53,54 A minimal stent CSA > 9 mm2 is associated with the lowest restenosis rates.45,55 While there are no published randomized studies of IVUS-guided DES deployment, IVUS guidance may be important to assure optimal stent expansion and strut apposition with DES.56 In addition to achieving larger final vessel sizes, IVUS guidance may be important in the detection of atherosclerosis plaque composition during PCI. Recent studies suggest that increased necrotic core plaque content detected by radiofrequency backscatter IVUS analysis (virtual histology) is an independent predictor of distal embolization during PCI in patients presenting with both STEMI and anginal syndromes.57,58 As distal protection devices may reduce peri-procedural embolization, it may be important to identify necrotic core content before stent

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

Cath Lab Digest - March 2008 Are You Being Paid Fair Market Value in 2008? A Cardiac Cath Lab Professionals Survey by Cath Lab Digest and the Society of Invasive Cardiovascular Professionals Saint Joseph’s Hospital Invasive Imaging Tools for Optimizing Coronary Stent Deployment Contents Clinical Editor’s Corner A Workflow Revolution in Cath Lab Reporting Advantages of a New Digital Lab at Baystate Medical Center Cardiac Computed Tomography: What Does it Mean for the Cath Lab? The Latest in Cardiac Magnetic Resonance Imaging (MRI) Cellular Cardiomyoplasty and Cardiac Regeneration Intravascular Ultrasound in the Cath Lab: A Powerful — and Underutilized — Tool to Improve Patient Outcomes The Stentplus™ Patient Success Program Cardiac Cath Lab Clutter — or, Spring into Action! Groin Bleeds and Other Hemorrhagic Complications of Cardiac Catheterization: A List of Relevant Issues Ask the Clinical Instructor: A Q&A Column for Those New to the Cath Lab What Do You Think? Experience with a New Guidewire: The Terumo Runthrough NS The Ostial Pro™ Stent Positioning System: Perfecting Aorto-Ostial Stent Placement Precious Minutes The Ten-Minute Interview with…Mark Bowles, BSN, CCRN Vascular Care in the Cath Lab: Planning a Smooth Transition Cath Laughs CMS 2008 OPPS Final Rule Review An Extensive Set of Review Courses for the CCI Basic Science, Non-Invasive Echocardiography and Vascular, and ARDMS Ultrasound Exams Meetings Calendar CEU Education Center Clinical & Industry News STEMI Interventions Classifieds Advertisers Index

Cath Lab Digest - March 2008

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