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Role of Novel Guidewire Support Devices for Crossing Coronary Artery Chronic Total Occlusions
Chronic total occlusions (CTOs) can be challenging to recanalize,1 with failure to cross the occlusion with a guidewire being the number one cause of failure, followed by development of a complication.2 Significant progress has, however, been made over time with 85% or higher procedural success rates currently being achieved at experienced centers around the world with low rates of major periprocedural complications.3-5
Can these favorable outcomes be achieved at less experienced centers? Unfortunately, not yet: procedural success between 2009 and 2013 in the National Cardiovascular Data Registry was 59%, significantly lower than the 96% procedural success achieved in non-CTO lesions during elective percutaneous coronary intervention (PCI).6 Moreover, major adverse cardiac events occurred twice as often (1.6% vs 0.8%; P<.001).6 Procedural efficiency also remains an issue: CTO-PCI still often requires long procedure and fluoroscopy times and high radiation doses for both the patient and the operator.3,7 Bridging the gap in success between experienced and less experienced centers and improving efficiency remain top priorities for CTO-PCI in 2016. How can these goals be achieved?
First, by intensive CTO-PCI education, both didactic and hands on.8,9 Second, by standardization and optimization of CTO-PCI approaches and techniques among various geographies and operators. Several procedural techniques are maturing to the point that they can be codified and standardized, such as the subintimal transcatheter withdrawal (STRAW) technique10 and the double-blind stick and swap technique11 for antegrade dissection and reentry. Moreover, multiple similarities are emerging between approaches used at different locations; for example, between the hybrid algorithm12 and the Asian-Pacific CTO Club algorithm.
Third, with new technology. For example, novel x-ray systems can significantly reduce radiation dose and could have a transformative impact on success rates by allowing repeated CTO crossing attempts (although this is not going to help with the efficiency of the procedure!).13 Unfortunately, few CTO devices have been successfully implemented in daily workflow – mainly the BridgePoint dissection and reentry system14 and novel microcatheters and guidewires.15-17 A new category of devices was recently introduced for CTO-PCI, ie, devices that improve guide catheter and guidewire support. Four such devices (Figure 1) are currently available in the United States: the MultiCross and CenterCross (Roxwood Medical)18 and the Prodigy and CrossLock (Radius Medical).19 The MultiCross and CenterCross have a stabilizing self-expanding scaffold that is deployed proximal to the target lesion. The MultiCross contains 3 microcatheters within the scaffold, each located 120° apart.18 The CenterCross has a single, large central lumen that can accommodate a microcatheter. The Prodigy and CrossLock are over-the-wire catheters with a distal elastomeric balloon (5 mm long; 6 mm diameter for the Prodigy and 8 mm for the CrossBoss) that centers the catheter in the blood vessel. The balloon is inflated at low pressure (1 atm) and the catheters have a short tip (<2 mm in length), allowing placement close to the occlusion. All these devices not only increase guidewire support, but may also assist with centering the wire, hence minimizing the risk for subintimal guidewire entry.
In this issue of the Journal of Invasive Cardiology, Walsh et al describe their initial clinical experience with a novel catheter designed to provide enhanced support for antegrade CTO-PCI, the NovaCross (Nitiloop, Ltd).20 The NovaCross has a flexible nitinol element at its distal tip with several helical struts that curve outward, providing support to the guidewire. It also has a 0.6 mm-diameter inner portion that can be extended distally up to 5 cm. In this first-in-man study, the NovaCross was studied in 24 patients at four centers in Europe and Israel to treat challenging lesions (80% with J-CTO score ≥3). In 2 patients, the device could not be used due to lack of appropriate landing zone. In the remaining 22 patients, technical success was achieved in 18 lesions (81.8%), whereas an adverse event occurred in 4 patients (16.7%). None of the adverse events were considered to be related to use of the device and none resulted in clinical sequelae for the patients.
The NovaCross first-in-man study results are encouraging, but given the small number of patients studied, additional investigation is warranted. Several questions remain: How many CTOs can be approached with the NovaCross or other similar devices? How many patients lack an appropriate landing zone or have proximal cap ambiguity precluding their use? Which coronary artery is best suited for these devices? Are the devices deliverable through tortuosity and do they preserve side branches? Does the device’s profile allow use of the trapping technique for equipment exchanges? Could the extra support provided by the devices increase the risk of guidewire perforation? Can the devices be effectively and safely used by less experienced operators than the expert operators participating in the pivotal study? Can those devices decrease the need for the retrograde approach and do they decrease the likelihood of subintimal guidewire crossing?
Additional studies and clinical experience with these devices will likely provide answers to the above questions, but at present they appear to be best suited for relatively short CTOs with a clear proximal cap and large, non-diseased, and non-tortuous proximal vessel that provides a welcoming landing zone for these devices.
Given the wide anatomic variability of CTOs, use of the NovaCross and other related devices is unlikely to be a “panacea” – it will likely greatly facilitate some procedures, yet be of limited utility in others. These devices are not a substitute for carefully studying the angiogram and devising a sequential procedural plan. They also do not obviate the need for learning and using other crossing devices and technique, as they are unlikely to be successful in all cases. They may, however, provide innovative solutions to various technical challenges, such as facilitating reverse controlled antegrade and retrograde tracking and dissection (reverse CART).
Despite their limitations, the NovaCross and other similar devices are a welcome addition to our armamentarium and can help us improve the success, safety, and efficiency of CTO-PCI, hopefully extending the benefits of revascularization to many more patients in need.21,22
References
1. Galassi A, Grantham A, Kandzari D, et al. Percutaneous treatment of coronary chronic total occlusion. Part 2: technical approach. Interv Cardiol Rev. 2014;9:201-207.
2. Sapontis J, Christopoulos G, Grantham JA, et al. Procedural failure of chronic total occlusion percutaneous coronary intervention: insights from a multicenter US registry. Catheter Cardiovasc Interv. 2015;85:1115-1122.
3. Christopoulos G, Karmpaliotis D, Alaswad K, et al. Application and outcomes of a hybrid approach to chronic total occlusion percutaneous coronary intervention in a contemporary multicenter US registry. Int J Cardiol. 2015;198:222-228.
4. Kandzari DE, Kini AS, Karmpaliotis D, et al. Safety and effectiveness of everolimus-eluting stents in chronic total coronary occlusion revascularization: results from the EXPERT CTO multicenter trial (Evaluation of the XIENCE Coronary Stent, Performance, and Technique in Chronic Total Occlusions). JACC Cardiovasc Interv. 2015;8:761-769.
5. Morino Y, Kimura T, Hayashi Y, et al. In-hospital outcomes of contemporary percutaneous coronary intervention in patients with chronic total occlusion insights from the J-CTO registry (Multicenter CTO Registry in Japan). JACC Cardiovasc Interv. 2010;3:143-151.
6. Brilakis ES, Banerjee S, Karmpaliotis D, et al. Procedural outcomes of chronic total occlusion percutaneous coronary intervention: a report from the NCDR (National Cardiovascular Data Registry). JACC Cardiovasc Interv. 2015;8:245-253.
7. Christopoulos G, Papayannis AC, Alomar M, et al. Effect of a real-time radiation monitoring device on operator radiation exposure during cardiac catheterization: the radiation reduction during cardiac catheterization using real-time monitoring study. Circ Cardiovasc Interv. 2014;7:744-750.
8. Sharma V, Jadhav ST, Harcombe AA, et al. Impact of proctoring on success rates for percutaneous revascularisation of coronary chronic total occlusions. Open Heart. 2015;2:e000228.
9. Stojkovic S, Sianos G, Katoh O, et al. Efficiency, safety, and long-term follow-up of retrograde approach for CTO recanalization: initial (Belgrade) experience with international proctorship. J Interv Cardiol. 2012;25:540-548.
10. Smith EJ, Di Mario C, Spratt JC, et al. Subintimal TRAnscatheter Withdrawal (STRAW) of hematomas compressing the distal true lumen: a novel technique to facilitate distal reentry during recanalization of chronic total occlusion (CTO). J Invasive Cardiol. 2015;27:E1-E4.
11. Christopoulos G, Kotsia AP, Brilakis ES. The double-blind stick-and-swap technique for true lumen reentry after subintimal crossing of coronary chronic total occlusions. J Invasive Cardiol. 2015;27:E199-E202.
12. Brilakis ES, Grantham JA, Rinfret S, et al. A percutaneous treatment algorithm for crossing coronary chronic total occlusions. JACC Cardiovasc Interv. 2012;5:367-379.
13. Christopoulos G, Christakopoulos GE, Rangan BV, et al. Comparison of radiation dose between different fluoroscopy systems in the modern catheterization laboratory: results from bench testing using an anthropomorphic phantom. Catheter Cardiovasc Interv. 2015;86:927-932.
14. Wosik J, Shorrock D, Christopoulos G, et al. Systematic review of the BridgePoint system for crossing coronary and peripheral chronic total occlusions. J Invasive Cardiol. 2015;27:269-276.
15. Khalili H, Vo M, Brilakis ES. Initial experience with the Gaia composite core guidewires in coronary chronic total occlusion crossing. J Invasive Cardiol 2016;28:E22-E25.
16. Brilakis ES, ed. Manual of Coronary Chronic Total Occlusion Interventions. A Step-By-Step Approach. Waltham, MA: Elsevier; 2013.
17. Galassi AR, Ganyukov V, Tomasello SD, Haes B, Leonid B. Successful antegrade revascularization by the innovation of composite core dual coil in a three-vessel total occlusive disease for cardiac arrest patient using extracorporeal membrane oxygenation. Eur Heart J. 2014;35:2009.
18. Mitsutake Y, Ebner A, Yeung AC, Taber MD, Davidson CJ, Ikeno F. Efficacy and safety of novel multi-lumen catheter for chronic total occlusions: from preclinical study to first-in-man experience. Catheter Cardiovasc Interv. 2015;85:E70-E75.
19. Moualla SK, Khan S, Heuser RR. Anchoring improved: introduction of a new over-the-wire support balloon. J Invasive Cardiol. 2014;26:E130-E132.
20. Walsh S, Dudek D, Bryniarski L, et al. Efficacy and safety of novel NovaCross microcatheter for chronic total occlusions: first-in-human study. J Invasive Cardiol. 2016;28:88-91.
21. Galassi AR, Brilakis ES, Boukhris M, et al. Appropriateness of percutaneous revascularization of coronary chronic total occlusions: an overview. Eur Heart J. 2015.
22. Christakopoulos GE, Christopoulos G, Carlino M, et al. Meta-analysis of clinical outcomes of patients who underwent percutaneous coronary interventions for chronic total occlusions. Am J Cardiol. 2015;115:1367-1375.
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From the 1VA North Texas Healthcare System and University of Texas Southwestern Medical Center, Dallas, Texas; 2Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy; and 3Department of Cardiology, University Hospital of Zurich, Zurich, Switzerland.
Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Brilakis reports consulting/speaker honoraria from Abbott Vascular, Asahi Intecc, Boston Scientific, Elsevier, Somahlution, St Jude Medical, and Terumo; research support from InfraRedx; spouse is employee of Medtronic. Dr Galassi reports no conflicts of interest regarding the content herein.
Address for correspondence: Emmanouil S. Brilakis, MD, PhD, Dallas VA Medical Center (111A), 4500 South Lancaster Road, Dallas, TX 75216. Email: esbrilakis@gmail.com
