Comparison Between Traditional and Guide-Catheter Extension Reverse Controlled Antegrade Dissection and Retrograde Tracking: Insights From the PROGRESS-CTO Registry

Abstract: Objectives. The most common re-entry technique during retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is reverse controlled antegrade and retrograde tracking (rCART). The use of guide-catheter extensions can facilitate rCART, but has received limited study. Methods. We compared the clinical and procedural characteristics and outcomes of traditional rCART vs guide-catheter extension rCART vs cases in which both techniques were used (combined rCART) in patients with successful retrograde CTO crossing in a contemporary multicenter CTO-PCI registry. Results. Between 2012 and 2018, rCART was used in 467 of 1336 retrograde CTO-PCI cases. Guide-catheter extension rCART was used in 60/467 cases (13%; use increased from 0% in 2012 to 26% in 2017). The traditional rCART group, guide-catheter extension rCART group, and combined rCART group had similar target lesion J-CTO scores (3.3 ± 1.1 vs 3.2 ± 1.2 vs 3.6 ± 0.8, respectively; P=.28), technical success rates (99% vs 100% vs 96.4%, respectively; P=.36), procedural success rates (93.2% vs 93.8% vs 96.3%, respectively; P=.82), and major in-hospital adverse cardiac event (MACE) rates (6.4% vs 9.4% vs 3.6%, respectively; P=.66). Total procedural time was longer in the combined rCART group (196 min [IQR, 146-256 min] vs 200 min [IQR, 164-293 min] vs 255 min  [IQR, 195-280 min], respectively; P<.01), with a trend for lower patient air kerma radiation dose in the guide-catheter extension groups (4.11 Gray [IQR, 2.49-5.77 Gray] vs 3.19 Gray [IQR, 1.29-4.74 Gray] vs 3.47 Gray [IQR, 2.89-5.56 Gray]; P=.07). Conclusions. Guide-catheter extension rCART is increasingly being used for retrograde CTO crossing and is associated with similar success and MACE rates as traditional rCART.

J INVASIVE CARDIOL 2019;31(1):27-34. (Epub 2018 November 11).

Key words: chronic total occlusion, percutaneous coronary intervention, retrograde approach, reverse controlled antegrade and retrograde tracking, guide-catheter extension

The retrograde approach is commonly utilized in contemporary chronic total occlusion (CTO) percutaneous coronary interventions (PCI); it was used in 39% of cases in the PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention, NCT02061436) registry. Retrograde crossing involves advancement of a guidewire through a collateral vessel or a bypass graft distal to the occlusion, followed by crossing against the former direction of blood flow.^1-6 Septal collaterals are the most commonly used and safest conduits (together with patent saphenous vein grafts) for retrograde CTO-PCI. Epicardial collaterals can be challenging to cross due to tortuosity and carry higher risk for tamponade in case of perforation.⁷ In patients with prior coronary artery bypass graft (CABG) surgery, arterial or saphenous vein grafts (SVGs) or left internal mammary artery (LIMA) grafts can also be used as retrograde conduits.^8,9

During the retrograde approach, guidewire crossing can occur from the distal to the proximal true lumen (true-to-true retrograde wire crossing) or from the proximal to the distal true lumen (“just marker” technique, in which the retrograde guidewire serves as a marker of the distal true lumen position, helping to direct antegrade guidewire crossing). In most cases, however, either the antegrade or the retrograde guidewire enter the subintimal space, requiring re-entry into the true lumen, which is most commonly achieved by inflating a balloon over the antegrade guidewire, followed by advancement of a retrograde guidewire into the proximal true lumen (the reverse controlled antegrade and retrograde tracking [rCART] technique).^4,10-12 A modification of the rCART technique is use of a guide-catheter extension through the antegrade guide catheter that serves as a target for the retrograde guidewire.^13,14 This technique is illustrated in Figure 1. We used a contemporary multicenter CTO-PCI registry to determine the frequency and outcomes of guide-catheter extension rCART.

Methods

Between January 2012 and May 2018, a total of 1336 retrograde CTO-PCI cases were performed at 20 centers in the United States, Europe, and Russia and were included in the PROGRESS-CTO registry. The reverse CART technique was used in 476 CTO-PCI cases. All cases included in the current analysis had successful retrograde crossing. Cases in which >1 CTO lesion was attempted during the same procedure were excluded, leaving 467 CTO-PCIs for analysis. We compared the clinical, angiographic, and procedural characteristics, as well as outcomes of traditional rCART vs guide-catheter extension rCART vs cases where both traditional rCART and guide-catheter extension rCART (combined rCART) were used. The study was approved by the institutional review board of each center. 

Definitions. Coronary CTOs were defined as coronary lesions with Thrombolysis in Myocardial Infarction (TIMI) grade 0 flow of at least 3-month duration. Estimation of the duration of occlusion was clinical, based on the first onset of angina, prior history of myocardial infarction in the target-vessel territory, or comparison with a prior angiogram. Calcification was assessed by angiography as mild (spots), moderate (involving ≤50% of the reference lesion diameter), and severe (involving >50% of the reference lesion diameter). Moderate proximal vessel tortuosity was defined as the presence of at least 2 bends >70° or 1 bend >90° and severe tortuosity as 2 bends >90° or 1 bend >120° in the CTO vessel. Blunt or no stump was defined as lack of tapering or lack of a funnel shape at the proximal cap. Interventional collaterals were defined as collaterals considered amenable to crossing by a guidewire and a microcatheter by the operator. A retrograde procedure was defined as an attempt to cross the lesion through a collateral vessel or bypass graft supplying the target vessel distal to the lesion. The just marker technique was defined as use of the retrograde guidewire as a marker for the antegrade guidewire crossing. Antegrade dissection/re-entry was defined as antegrade PCI during which a guidewire was intentionally introduced into the subintimal space proximal to the lesion, or re-entry into the distal true lumen was attempted following intentional or inadvertent subintimal guidewire or device crossing. 

Reverse CART performed without use of a guide-catheter extension was termed traditional rCART, whereas reverse CART performed with a guide-catheter extension was termed guide-catheter extension rCART. We defined cases of reverse CART in which both traditional rCART and guide-catheter extension rCART as combined rCART. Moreover, according to a recent consensus report on reverse CART terminology, the following definitions were used: (1) conventional rCART, which usually involves use of large balloons on the antegrade wire to achieve re-entry within the CTO segment; and (2) directed rCART, which is characterized by small antegrade balloon size and more active, intentional vessel tracking and penetration with a controllable retrograde wire, still within the CTO segment.¹² 

Technical success was defined as successful CTO revascularization with achievement of <30% residual diameter stenosis within the treated segment and restoration of TIMI grade 3 antegrade flow. Procedural success was defined as the achievement of technical success without any in-hospital major adverse cardiac event (MACE). In-hospital MACE included any of the following adverse events prior to hospital discharge: death, myocardial infarction, recurrent symptoms requiring urgent repeat target-vessel revascularization with PCI or CABG, tamponade requiring either pericardiocentesis or surgery, and stroke. Myocardial infarction (MI) was defined using the Third Universal Definition of Myocardial Infarction (type 4 MI).¹⁵ The J-CTO score was calculated as described by Morino et al,¹⁶ the PROGRESS-CTO score as described by Christopoulos et al,¹⁷ and the PROGRESS-CTO Complications score as described by Danek et al.¹⁸

Statistical analysis. Categorical variables were expressed as percentages and were compared using Pearson’s Chi-square test. Continuous variables were presented as mean ± standard deviation or median (interquartile range [IQR]) unless otherwise specified and were compared using the ANOVA or Kruskal-Wallis test, as appropriate. All statistical analyses were performed with JMP 14.0 (SAS Institute). A two-sided P-value of .05 was considered statistically significant.

Results

Clinical and angiographic characteristics. Among CTO-PCI rCART cases with successful retrograde crossing included in the registry, the traditional rCART technique was used in 407 (87.2%), guide-catheter extension rCART was used in 32 cases (6.8%), and combined rCART was used in 28 cases (6.0%). The use of guide-catheter extension rCART increased over time (from 0.0% in 2012 to 26.0% in 2017). The baseline clinical and angiographic characteristics of the study patients and lesions are summarized in Table 1 and Table 2. Patient age was similar between the three groups, but the guide-catheter extension rCART group included fewer men (89.2% in the traditional rCART group vs 68.8% in the guide-catheter extension group vs 89.3% in the combined rCART group; P<.01). 

The right coronary artery was the most common CTO target vessel for all groups (75.3% vs 81.2% vs 92.6%; P=.06). There was no difference in CTO length (40 mm [IQR, 28-60 mm] vs 40 mm [IQR, 26-60 mm] vs 40 mm [IQR, 40-50 mm]; P=.41), prevalence of moderate or severe tortuosity (52.6% vs 37.5% vs 67.9%; P=.06), and proximal cap ambiguity (52.0% vs 46.9% vs 46.4%; P=.75), but the target-vessel diameter was larger in the traditional rCART group (3.08 ± 0.54 mm vs 2.80 ± 0.34 mm vs 2.99 ± 0.49 mm; P=.02) while moderate or severe calcification was more common in the combined rCART group (73.2% vs 53.1% vs 89.3%; P<.01). There was no difference in J-CTO score (3.3 ± 1.1 vs 3.2 ± 1.2 vs 3.6 ± 0.8; P=.28), PROGRESS-CTO score (1.3 ± 0.9 vs 1.0 ± 1.0 vs 1.2 ± 0.9; P=.41) and PROGRESS-CTO Complications score (4.1 ± 1.8 vs 3.8 ± 1.6 vs 4.5 ± 1.7; P=.30).

Interventional techniques. CTO-PCI techniques and outcomes are described in Table 3 and Table 4. The frequency of use of septal collaterals (63.9% vs 68.8% vs 75.0%; P=.44) and epicardial collaterals (31.2% vs 18.8% vs 21.4%; P=.20) was similar in the three groups. The combined rCART group had more stents implanted (3.2 ± 1.0 vs 3.1 ± 1.0 vs 3.7 ± 1.1; P=.02) but had lower utilization of intravascular ultrasound for crossing (11.0% vs 17.2% vs 0.0%; P=.03).

In the traditional rCART group, conventional rCART was the most common technique leading to successful crossing (94.3%), followed by retrograde true to true puncture (3.2%), and directed rCART (1.6%). In the guide-catheter extension rCART group, the technique that led to successful crossing was the guide-catheter extension rCART (100%) in all cases, while in the combined rCART group, guide-catheter extension rCART was the successful crossing technique in 67.9% and the conventional rCART was successful in 32.1% (P<.001 for all comparisons).

Procedural outcomes and complications. Procedural outcomes and complications are outlined in Table 5. There was no difference between groups in technical success (99.0% vs 100% vs 96.4%; P=.36), procedural success (93.2% vs 93.8% vs 96.3%; P =.82), and MACE (6.4% vs 9.4% vs 3.6%; P=.66) (Figure 2). Strokes occurred only in the guide-catheter extension rCART group (0.0% vs 6.2% vs 0.0%; P<.001) which also had more vascular access complications (1.7% vs 9.4% vs 7.1%; P<.01).

Procedural time was significantly longer for the combined rCART group compared with the other two groups (196 min [IQR, 146-256 min] vs 200 min [IQR, 164-293] vs 255 min [IQR, 195-280 min]; P<.01). However, there was a trend for lower air kerma radiation dose in the guide-catheter extension rCART group (3.19 Gray [IQR, 1.29-4.74 Gray]) compared with the combined rCART group (3.47 Gray [IQR, 2.89-5.56 Gray]) and traditional rCART group (4.11 Gray [IQR, 2.49-5.77 Gray]) (P=.07). The volume of contrast used was similar in the 3 groups (275 mL [IQR, 201-375 mL] vs 280 mL [IQR, 200-375 mL] vs 233 mL [170-328 mL]; P=.22). 

Discussion

To the best of our knowledge, this is the first systematic study of guide-catheter extension rCART, demonstrating increasing use over time and outcomes similar to traditional rCART.

Reverse CART is the dominant strategy for retrograde dissection and re-entry,^19,20 especially for complex CTOs.²¹ Guide-catheter extension rCART can facilitate retrograde guidewire crossing in several ways.²² First, this technique decreases the distance that needs to be traversed by the retrograde guidewire before entering the antegrade guide catheter, which can be critical when traversing long collaterals or when regular-length guide catheters are used. Second, this technique prevents tissue recoil in areas of dissection, hence enlarging the target area for the retrograde guidewire to enter. Third, this technique prevents injury of the proximal vessel by ensuring that re-entry occurs more distally in the vessel, which is of particular importance in patients with CTOs in the left anterior descending  artery and the circumflex artery. Use of guide-catheter extensions in this setting can prevent inadvertent left main dissection and possibly occlusion of a major branch, which can lead to severe ischemia and hemodynamic collapse.²³ Fourth, this technique facilitates delivery of an antegrade balloon. There are several guide-catheter extension sizes (5.5 Fr, 6 Fr, 7 Fr, and 8 Fr). Larger ones facilitate re-entry, but are often more challenging to deliver to the re-entry zone.

Study limitations. Our study did not show improved safety or efficiency with guide-catheter extension rCART (with the exception of higher stroke rate, which is most likely a play of chance), but this was not a randomized comparison and only successful retrograde crossing CTO cases were included. When guide-catheter extension rCART was used either as the only technique or in combination with traditional rCART, it was associated with higher procedural time, but also with a trend for lower air kerma radiation and use of fewer stents. The number of patients included was relatively small and long-term follow-up was not available. Moreover, treatment of non-CTO lesions during CTO-PCI was more common in the traditional rCART group than in the other two groups, which could have affected procedural time, air kerma dose, and contrast volume. Additional limitations were lack of core laboratory assessment of the study angiograms or clinical events committee adjudication. Finally, the procedures were performed by experienced CTO operators in dedicated, high-volume centers, limiting extrapolation to less experienced operators and centers.

Conclusion

Guide-catheter extension rCART is a novel technique that may facilitate retrograde CTO crossing. 

Acknowledgments. Study data were collected and managed using Research Electronic Data Capture (REDCap) electronic data capture tools hosted at the Minneapolis Heart Institute Foundation (MHIF) in Minneapolis, Minnesota. REDCap is a secure, web-based application designed to support data capture for research studies, providing: (1) an intuitive interface for validated data entry; (2) audit trails for tracking data manipulation and export procedures; (3) automated export procedures for seamless data downloads to common statistical packages; and (4) procedures for importing data from external sources.

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From the ¹Minneapolis Heart Institute, Abbott Northwestern Hospital, Minneapolis, Minnesota; ²Columbia University, New York, New York; ³Henry Ford Hospital, Detroit, Michigan; ⁴Massachusetts General Hospital, Boston, Massachusetts; ⁵Beth Israel Deaconess Medical Center, Boston, Massachusetts; ⁶VA San Diego Healthcare System and University of California San Diego, La Jolla, California; ⁷Baylor Heart and Vascular Hospital, Dallas, Texas; ⁸Medical Center of the Rockies, Loveland, Colorado; ⁹University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; ¹⁰VA Central Arkansas Healthcare System, Little Rock, Arkansas; ¹¹Meshalkin Novosibrisk Research Institute, Novosibirsk, Russia; ¹²The Heart Hospital Baylor Plano, Plano, Texas; ¹³Torrance Memorial Medical Center, Torrance, California; ¹⁴Piedmont Heart Institute, Atlanta, Georgia; ¹⁵VA Minneapolis Healthcare System and University of Minnesota, Minneapolis, Minnesota; ¹⁶Red Cross Hospital of Athens, Athens, Greece; ¹⁷Emory University Hospital Midtown, Atlanta, Georgia; ¹⁸University of Szeged, Division of Invasive Cardiology, Second Department of Internal Medicine and Cardiology Center, Szeged, Hungary; and ¹⁹VA North Texas Health Care System and University of Texas Southwestern Medical Center, Dallas, Texas.

Funding: The Progress CTO registry has received support from the Abbott Northwestern Hospital Foundation.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Karmpaliotis reports speaker honoraria from Abbott Vascular, Boston Scientific, Medtronic, and Vascular Solutions. Dr Alaswad reports consulting fees from Terumo and Boston Scientific; consultant, non-financial, for Abbott Laboratories. Dr Jaffer reports consultant income from Abbott Vascular, Boston Scientific, and Siemens; research grants from Canon, Siemens, and the National Institutes of Health. Dr Yeh reports the Career Development Award (1K23HL118138) from the National Heart, Lung, and Blood Institute. Dr. Patel reports speakers’ bureau income from Astra Zeneca. Dr Mahmud reports consulting fees from Medtronic and Corindus; speaker honoraria from Medtronic, Corindus, and Abbott Vascular; educational program fees from Abbott Vascular; and clinical events committee fees from St. Jude. Dr Burke reports consulting and speaker honoraria from Abbott Vascular and Boston Scientific. Dr Wyman reports speakers’ bureau income from Boston Scientific, Abbott Vascular, and Asahi Intecc; honoraria from Boston Scientific, Abbott Vascular, and Asahi Intecc; consultant/advisory board income from Boston Scientific, Abbott Vascular, and Asahi Intecc. Dr Kandzari reports research grants from Boston Scientific, Medtronic Cardiovascular, and Abbott; consultant/advisory board income from Boston Scientific and Medtronic Cardiovascular. Drs Garcia, Koutouzis, Tsiafoutis, Jaber, and Samady report consulting fees from Medtronic. Dr Moses reports consultant income from Boston Scientific and Abiomed. Dr Lembo reports speakers’ bureau income from Medtronic; consultant/advisory board income from Abbott Vascular and Medtronic. Dr Parikh reports speakers’ bureau income from Abbott Vascular, Medtronic, CSI, Boston Scientific, and Trireme; advisory board income from Medtronic, Abbott Vascular, and Philips. Dr Kirtane reports institutional research grants to Columbia University from Boston Scientific, Medtronic, Abbott Vascular, Abiomed, St. Jude Medical, Vascular Dynamics, Glaxo SmithKline, and Eli Lilly. Dr Ali reports consultant fees/honoraria from St. Jude Medical and AstraZeneca Pharmaceuticals; ownership interest/partnership/principal in Shockwave Medical and VitaBx; research grants from Medtronic and St. Jude Medical. Dr Rangan reports research grants from InfraReDx and The Spectranetics Corporation. Dr Banerjee reports research grants from Gilead and The Medicines Company; consultant/speaker honoraria from Covidien and Medtronic; ownership in MDCare Global (spouse); intellectual property in HygeiaTel. Dr. Brilakis reports consulting/speaker honoraria from Abbott Vascular, ACIST, American Heart Association (associate editor Circulation), Amgen, Asahi Intecc, Cardiovascular Innovations Foundation (Board of Directors), CSI, Elsevier, GE Healthcare, and Medtronic; research support from Boston Scientific, Siemens, Regeneron, and Osprey; shareholder in MHI Ventures; Board of Trustees for the Society of Cardiovascular Angiography and Interventions. The remaining authors report no conflicts of interest regarding the content herein.

Manuscript submitted August 14, 2018, final version accepted August 27, 2018.

Address for correspondence: Emmanouil S. Brilakis, MD, PhD, Minneapolis Heart Institute, 920 E. 28th Street #300, Minneapolis, MN 55407. Email: esbrilakis@gmail.com