|Year : 2019 | Volume
| Issue : 2 | Page : 47-52
Predictors of failure of retrograde approach for percutaneous intervention of coronary chronic total occlusion: A single-center experience
Jianying Ma1, Shufu Chang1, Jing Xie2, Qing Qin1, Rende Xu1, Kang Yao1, Dong Huang1, Feng Zhang1, Lei Ge1, Juying Qian1, Junbo Ge1
1 Department of Cardiology, Shanghai Institute of Cardiovascular Disease, Zhongshan Hospital, Fudan University, Shanghai, China
2 Department of Cardiology, Second Hospital of Kashi City, Xinjiang, China
|Date of Submission||21-Jan-2019|
|Date of Acceptance||21-Jan-2019|
|Date of Web Publication||26-Jun-2019|
Department of Cardiology, Shanghai Institute of Cardiovascular Disease, Zhongshan Hospital, Fudan University, Shanghai 200032
Source of Support: None, Conflict of Interest: None
Objective: The aim of the study is to assess the predictors of failure of percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) lesions using a retrograde approach. Methods: The present study retrospectively enrolled all 211 patients who underwent retrograde CTO PCI from January 2009 to December 2015 at Shanghai Institute of Cardiovascular Disease. Multivariate Cox regression analysis was used to assess potential predictors of retrograde CTO PCI failure including sex, vascular access site, sheath size, prior PCI, prior coronary artery bypass grafting, history of myocardial infarction, target vessel of CTO, J-CTO score, retrograde wire crossing collaterals, and reverse controlled antegrade and retrograde subintimal tracking (CART) use. Results: Of the 211 patients studied, retrograde CTO PCI was successful in 115 (54.5%) patients, and in an additional 46 (21.8%) with an antegrade approach after retrograde failure. For the 50 (23.7%) patients who failed both retrograde and antegrade approaches, the most common (50% [25/50]) reason was inability to cross collaterals with the retrograde wire. This group of patients had fewer instances of a prior PCI (P < 0.05). Retrograde CTO PCI failure rate was lower with increasing sheath size and with either radial-only or one radial and one femoral access versus femoral-only access (P < 0.05). A multivariate Cox regression analysis showed that the inability to cross collaterals with the retrograde wire (hazard ratio, 5.52 [95% confidence interval, 2.08–12.81];P < 0.001), no prior PCI (3.27 [1.24–8.58];P = 0.01), and no reverse CART use (4.19 [1.33–13.19];P = 0.03) were an independent predictors of retrograde CTO PCI failure. Conclusion: Independent predictors of retrograde CTO PCI failure were the inability to cross collaterals with the retrograde wire, no prior PCI, and no reverse CART use. Vascular access site and sheath size do not have effect on the success of the retrograde approach.
Keywords: Chronic total occlusions, coronary artery, radial, retrograde approach intervention, sheath
|How to cite this article:|
Ma J, Chang S, Xie J, Qin Q, Xu R, Yao K, Huang D, Zhang F, Ge L, Qian J, Ge J. Predictors of failure of retrograde approach for percutaneous intervention of coronary chronic total occlusion: A single-center experience. Cardiol Plus 2019;4:47-52
|How to cite this URL:|
Ma J, Chang S, Xie J, Qin Q, Xu R, Yao K, Huang D, Zhang F, Ge L, Qian J, Ge J. Predictors of failure of retrograde approach for percutaneous intervention of coronary chronic total occlusion: A single-center experience. Cardiol Plus [serial online] 2019 [cited 2019 Aug 21];4:47-52. Available from: http://www.cardiologyplus.org/text.asp?2019/4/2/47/261434
Authors Jianying Ma, Shufu Chang, Jing Xie contributed equally to this paper.
| Introduction|| |
Although chronic total occlusion (CTO) lesions have been reported in 18.4%–26.4% of patients with obstructive coronary artery disease,, their recanalization was attempted in only 2.4%–15% of cases with percutaneous coronary intervention (PCI),,, with most cases treated with coronary artery bypass grafting (CABG) or medical therapy.
Studies have demonstrated that successful percutaneous recanalization of CTO is associated with reduction of symptoms, improvement of left ventricular function and a reduction of CABG,,,, and even mortality. However, the success rate of CTO PCI, even with retrograde approach, remains low compared with that of non-CTO PCI.,,,,,,, Our and others' previous studies have documented that inability to cross collaterals with the retrograde wire is a significant contributor in the failure of retrograde technique., The access site may also influence the failure rate of retrograde CTO PCI, being lower with the femoral route; however, few studies have analyzed the effect of access site on the success rate of retrograde CTO PCI.,
The present study aimed to determine the independent predictors of retrograde CTO PCI failure in a high volume, single center.
| Methods|| |
The present study retrospectively enrolled all 211 patients in whom PCI for a coronary CTO was attempted with retrograde approach between January 2009 and December 2015 at Shanghai Institute of Cardiovascular Disease. All patients in this study had at least one CTO lesion and exercise-induced angina, but no previous PCI attempt with retrograde approach. No clinical exclusion criteria were applied. The study complied with the Declaration of Helsinki and was approved by the Institutional Ethics Review Board. All patients provided general informed consent.
A CTO lesion was defined as thrombolysis in myocardial infarction (TIMI) 0 flow in the target vessel lasting for over 3 months. Duration of occlusion was determined by the interval from the last episode of acute coronary syndrome based on clinical symptoms or proven by the previous angiography. When the duration was unclear, the angiographic image was reviewed by two experienced operators to decide whether it was a CTO or not.
Exclusion criteria based on CTO lesions were: (1) the target CTO vessel was related to a myocardial infarction (MI) <3 months prior; (2) a CTO duration of <3 months even without a history of MI; (3) concomitant conditions, such as valve disease, requiring cardiac surgical treatment; (4) severe health conditions that rendered retrograde CTO PCI intolerable; and (5) nonretrograde CTO PCI.
Angiographic assessment of collateral connections (CC) was based on Werner's classification: CC0 – no continuous connection between donor and recipient artery; CC1 – continuous, thread-like connection; and CC2 – continuous, small side branch-like size of the collateral throughout its course.
Major adverse cardiac events were a composite of cardiac death, MI, and target vessel revascularization (TVR), either percutaneous or surgical. All deaths were considered cardiac unless otherwise documented.
A non-Q-wave, PCI-related MI was defined as the elevation of cTn values (>5 × 99th percentile upper reference limit http://www.cardiologyplus.org/article.asp?issn=2470-7511;year=2019;volume=4;issue=2;spage=47;epage=52;aulast=Ma) in patients with normal baseline values (≤99th percentile URL) or a rise of cTn values >20% if baseline values were elevated and stable or falling. When there were new pathological Q-waves in the electrocardiogram in addition to enzyme elevation, the event was defined as a Q-wave MI. TVR was defined as repeat revascularization within the treated vessel. Angiographic success was defined as restoration of TIMI flow Grade 3 with stent implantation in the occluded segments and residual stenosis <20% by visual estimate.
Techniques for retrograde approach have been described in detail in previous studies by our center.,
Continuous variables are presented as mean ± standard deviation and were compared using the Fisher exact test and if normally distributed, with a two-tailed independent samples t-test. Categorical variables were represented as numbers and percentages and were compared using a Chi-square test. A two-tailed P < 0.05 was considered statistically significance. Multivariate Cox regression analysis was used to assess potential predictors of retrograde CTO PCI failure including sex, vascular access site, sheath size, prior PCI, prior CABG, history of MI, target vessel of CTO, Japan-CTO (J-CTO) score, retrograde wire crossing collaterals, and reverse controlled antegrade and retrograde subintimal tracking (CART) use. Statistical analyses were performed using SPSS 15.0 statistical software package (SPSS Inc., Chicago, IL, USA)
| Results|| |
Baseline patient and lesion characteristics
Of the 211 patients studied, retrograde CTO PCI was successful in 115 (54.5%) patients, and in an additional 46 (21.8%) with antegrade approach after retrograde failure. Among patients who failed both retrograde and antegrade approaches, the mean age was greater than in patients with successful retrograde CTO PCI, and frequency of prior PCI was lower than in patients with successful retrograde or retrograde-antegrade CTO PCI [P < 0.05; [Table 1].
|Table 1: Baseline characteristics of patients undergoing retrograde chronic total occlusion percutaneous coronary intervention|
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Target vessel and history of percutaneous coronary intervention
Failure rate of previous target CTO PCI was similarly distributed among the three groups (P > 0.05). Right coronary artery (RCA) and left anterior descending (LAD) were more common than the left circumflex as the target CTO vessel, which was similarly distributed among the three groups (P > 0.05) [Table 2]. Seven patients had an in-stent occlusion, two with LAD CTO, and five with RCA CTO.
|Table 2: Previous percutaneous coronary intervention history and target vessel for chronic total occlusion|
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Annual number and success rate of retrograde chronic total occlusion percutaneous coronary intervention
The number and success rate of retrograde CTO PCI were: 12 and 91.7% (11/12) in 2009; 13 and 100% (13/13) in 2010; 15 and 60% (9/15) in 2011; 15 and 86.7% (13/15) in 2012; 32 and 84.4% (27/32) in 2013; 58 and 79.3% (46/58) in 2014; and 66 and 63.6% (42/66) in 2015, respectively [Figure 1].
Effect of vascular access site and sheath size on success rate of retrograde chronic total occlusion percutaneous coronary intervention
Retrograde CTO PCI was performed using radial-only access in 70 patients, one radial and one femoral in 74, and femoral only in 67 patients, with success rate of 70% (49/70), 71.6% (53/74), and 88.1% (59/67), respectively (P < 0.05). Failure rate decreased with increasing sheath size (P < 0.05). However, J-CTO score did not differ significantly among access sites or sheath sizes, and the latter did not differ significantly among J-CTO score groups (P > 0.05) [Table 3] and [Table 4].
|Table 3: Association of access site and sheath size on success rate of retrograde chronic total occlusion percutaneous coronary intervention|
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|Table 4: Access site of retrograde chronic total occlusion percutaneous coronary intervention according to J chronic total occlusion score|
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Techniques for retrograde approach
Retrograde approach as the first choice was performed in 11.8% (25/211) of patients with 92% (23/25) success, with antegrade technique yielding success in the remaining 2. Retrograde technique was used immediately after the failure of antegrade technique in 33.2% (70/211) of patients with 100% success. Switching between retrograde and antegrade techniques several times was done in 30.8% (65/211) of patients, with 67.7% (44/65) success for retrograde and 32.3% (21/65) for antegrade technique.
Among retrograde approach techniques, reverse CART was used in 33.6% (71/211), retrograde wire crossing in 12.3% (26/211), and kissing microcatheter (Rendezvous) in 10.9% (23/211) of patients.
Reasons for failure of retrograde chronic total occlusion percutaneous coronary intervention
The most common reason for failure of both the retrograde and antegrade approaches was inability to cross collaterals with retrograde wire in 50% (25/50), followed by inability to cross CTO lesion with retrograde wire in 22% (11/50) of patients. In 12% (6/50) of patients, the reason was inability to cross the collaterals with microcatheter. Other reasons included damage of collateral (4% [2/50]) and the patient's intolerance 6% (3/50). Among the latter 3, the retrograde wire advanced into the coronary sinus in one patient; a second patient experienced acute donor artery occlusion and a stent was implanted immediately in the donor artery and retrograde technique discontinued; and in the third patient, a large hematoma formed at the femoral puncture site with hypotension.
Independent predictors of failure of retrograde chronic total occlusion percutaneous coronary intervention
In a multivariate Cox regression analysis, the independent predictors of retrograde CTO PCI failure were inability to cross collaterals with retrograde wire (hazard ratio, 5.52 [95% confidence interval, 2.08–12.81]; P < 0.001), no prior PCI (3.27 [1.24–8.58]; P = 0.01), and no reverse CART use (4.19 [1.33–13.19]; P = 0.03). Other factors, such as gender, vascular access site, sheath size, prior CABG, history of MI, and vessel of CTO and J-CTO score, did not have the ability to predict failure of retrograde (P > 0.05).
Pericardial tamponade occurred in 4 (1.9%) patients, 1 in success of retrograde group and 3 in failure of retrograde and success of antegrade group. Three (1.4%) patients developed pericardial effusion not requiring treatment, one for each group. PCI-related MI occurred in 81.7% (94/115) of patients in the success of retrograde group, 82.6% (38/46) in the failure of retrograde and success of antegrade group, and 82% (41/50) in the failure of both retrograde and antegrade group (P > 0.05). Eleven patients with collateral perforation were treated with coils, including eight in success of retrograde group, one in failure of retrograde and success of antegrade group, and two in failure of both retrograde and antegrade group. In one patient, the coils were implanted into collaterals both antegradely and retrogradely. There were two patients with collateral perforation treated with fatty tissue and self-blood clot, respectively. No patient was converted to CABG. There was no death during the time of hospitalization.
| Discussion|| |
The three main findings of the present retrospective, single-center study were: (1) predictors of retrograde CTO PCI failure were inability to cross collaterals with retrograde wire (the most common reason for failure), no prior PCI, and no CART technique use; (2) J-CTO score did not influence the failure rate of retrograde CTO PCI, which was higher for the femoral approach compared with radial or one radial and one femoral or radial approach; and (3) the rates of complications of retrograde CTO PCI were low except for that of PCI-related MI.
Since first reported in 1990, PCI for CTO has gained traction over recent years due to the advent of dedicated devices and the introduction of new techniques. However, a large proportion of patients with CTOs continue to be managed by medical treatment or CABG, especially those with low J-CTO score-predicted success rate. CTO PCI is complex and time-consuming, and the retrograde approach remains technically challenging for complex CTO lesions not amenable to antegrade techniques.
One of the independent predictors of successful guide wire crossing within 30 min is a previously failed lesion. However, the latter finding was not reproduced in the present study. On the contrary, patients in whom both retrograde and antegrade approaches failed had a lower incidence of prior PCI than those in whom retrograde or antegrade approaches were successful. There are several explanations for the latter finding: (1) previous history of PCI grants operators a better chance to understand target vessel morphology and analyze the obstacles which might be encountered while carefully considering the techniques to be used in the current retrograde CTO PCI and (2) J-CTO score is used for prediction of wire passage of CTO lesion. However, in the present study, previously failed lesion or J-CTO score were not independent predictors of failure of the retrograde approach, which may be because when retrograde technique is required during CTO PCI, an attempt with antegrade is usually considered as preparation for the guidance of retrograde wire crossing the lesion or preparation of reverse CART.
In recent years, the use of radial approach has been increasingly favored for coronary PCI, with a significant decrease in the use of femoral artery access., Usually, after coronary angiography is done by radial access, retrograde technique is performed using bilateral radial approach or one radial and one femoral approach. It has the advantage of less discomfort compared with bilateral femoral approach. However, few studies have investigated the association between transradial or transfemoral access or sheath size and success rate of retrograde technique.,, Previous studies have shown that the procedural success rates were not statistically different for CTO PCI, and when only cases with J-CTO scores of > 3 were examined, the transradial group had a significantly lower success rate than the transfemoral group., In the present study, the success rate of retrograde CTO PCI was lower for radial, bilateral radial or one radial, and one femoral approaches than for bilateral femoral approach. However, the success rate of retrograde CTO PCI was significantly higher for one 6F and one 8F, or 7F both or larger, than for other sheath sizes. The latter results suggest that when retrograde approach is considered during CTO PCI, using femoral access and 7F or larger sheath would be preferred. It is believed that a larger sheath size has a larger inner space to hold more devices thereby providing additional support for complex CTO lesions, which might be the reason for the higher success rate. However, the present study also showed that access site and sheath size are not independent predictors of retrograde CTO PCI failure. A larger sized catheter can provide more support and hold more devices for antegrade technique, such as intravascular ultrasound (IVUS) and microcatheter together, among others. In retrograde approach, the support is easily obtained with RG3 wire externalization. When IVUS was used to localize the retrograde wire, it was unnecessary for the antegrade catheter to hold the microcatheter and IVUS simultaneously, which might be the reason why access site and sheath size were not predictors of retrograde approach failure. Attention should be paid to avoiding complications of femoral access as illustrated by the patient who developed a large hematoma at the femoral access site accompanied by hemodynamic instability which led to procedure discontinuation.
In the present study, the success rate of retrograde CTO PCI decreased after 2009. The reason might be related to the selection of much more complex cases for retrograde approach in recent years. In early years, collaterals might have been adequate for retrograde wire crossing, while later, more complex cases with harder-to-cross collaterals might have been selected.
For retrograde approach, wire passage of collaterals is the most important factor for prediction of the success rate of CTO PCI. Our previous study showed that success rate was higher after retrograde wire crossing of collaterals than for the failure group. After wire crossing collaterals, several additional techniques can be performed, such as reverse CART and kissing microcatheter, among others, to facilitate retrograde wire passage of the CTO lesion and into the antegrade catheter. If the retrograde wire fails to cross the CTO lesion, another attempt with antegrade technique can be performed immediately. Since the retrograde wire can show CTO body morphology, success can be more readily achieved with the antegrade wire in this situation. As shown in the present study, antegrade approach succeeded in 46 patients after failure of retrograde technique, which underscores the previous findings and favors immediately conversion to antegrade approach if retrograde approach fails. In the present study, the retrograde wire failed to cross the CTO lesion in 11 patients, which usually happens with long, tortuous lesions, and sometimes with calcification and is the another cause of retrograde CTO PCI failure. The third reason for failure of retrograde is inability of the microcatheter to cross the collateral, which was more common during the early years of CTO PCI practice, but may still happen occasionally, particularly, when the collaterals are severely tortuous or have a large angle, among other circumstances. New microcatheters, such as Caravel, Finecross GT, and Corsair Pro, are still unavailable in China.
Rates of complications for retrograde technique were low except for PCI-related MI. In the present study, PCI-related MI was evaluated by troponin T which is more sensitive to detect myocardial damage after CTO PCI, which probably explains why PCI-related MI rate was higher than in the previous studies. Pericardial tamponade developed in 1.9% of patients. No patient was transferred to emergency CABG. Injury of collateral is common during retrograde approach; however, immediate treatment with a coil can prevent pericardial effusion and transfer to CABG. Sometimes, the coil should be implanted into the collateral both antegradely and retrogradely to prevent pericardial tamponade.
The present study has several limitations. First, because of its retrospective observational design with enrolment over 7 years, there is heterogeneity in techniques and devices used for CTO PCI during the study, such as more recent use of a hybrid approach and availability of devices, such as Gaia series wires. Furthermore, the volume of retrograde approach for each operator was not high enough at the beginning of retrograde approach use. However, because all operators in this study are high-volume CTO operators and basic retrograde approach technique did not change much from 2009 to 2015, the results of the present study are of significance for future management of CTO PCI. Second, although retrograde CTO PCI usually is performed after failure of antegrade approach, retrograde approach can be the first choice, especially when the collaterals are clearly seen and not tortuous. Moreover, because switching between retrograde and antegrade techniques can be carried out several times, some cases cannot be simply considered as failure of retrograde and success of antegrade approach. However, the aim of the present study was to evaluate predictors of failure of retrograde CTO PCI, and therefore it does not affect the study results. Finally, because there were seven groups of sheath sizes, selection bias for this parameter cannot be ruled out, warranting further study with more cases.
| Conclusion|| |
In the present retrospective, single-center experience, the inability to cross collaterals with retrograde wire, no prior PCI, and lack of use of reverse CART were independent predictors of retrograde CTO PCI failure. These predictors would suggest that the future of retrograde CTO PCI should be focused on how to improve the success rate of retrograde wire crossing collaterals. Vascular access site and sheath size do not have effect on the success of retrograde approach.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Fefer P, Knudtson ML, Cheema AN, Galbraith PD, Osherov AB, Yalonetsky S, et al.
Current perspectives on coronary chronic total occlusions: The Canadian multicenter chronic total occlusions registry. J Am Coll Cardiol 2012;59:991-7.
Tsai TT, Stanislawski MA, Shunk KA, Armstrong EJ, Grunwald GK, Schob AH, et al.
Contemporary incidence, management, and long-term outcomes of percutaneous coronary interventions for chronic coronary artery total occlusions: Insights from the VA CART Program. JACC Cardiovasc Interv 2017;10:866-75.
Grantham JA, Marso SP, Spertus J, House J, Holmes DR Jr., Rutherford BD. Chronic total occlusion angioplasty in the United States. JACC Cardiovasc Interv 2009;2:479-86.
Abbott JD, Kip KE, Vlachos HA, Sawhney N, Srinivas VS, Jacobs AK, et al.
Recent trends in the percutaneous treatment of chronic total coronary occlusions. Am J Cardiol 2006;97:1691-6.
Trivax JE, Safian RD. PCI of CTOs: Hope or hype? Catheter Cardiovasc Interv 2015;85:795-6.
Sapontis J, Salisbury AC, Yeh RW, Cohen DJ, Hirai T, Lombardi W, et al.
Early procedural and health status outcomes after chronic total occlusion angioplasty: A report from the OPEN-CTO registry (outcomes, patient health status, and efficiency in chronic total occlusion hybrid procedures). JACC Cardiovasc Interv 2017;10:1523-34.
Mitomo S, Naganuma T, Jabbour RJ, Sato K, Takebayashi H, Kobayashi T, et al.
Impact of target vessel on long-term cardiac mortality after successful chronic total occlusion percutaneous coronary intervention: Insights from a Japanese multicenter registry. Int J Cardiol 2017;245:77-82.
Elias J, van Dongen IM, Hoebers LP, Ouweneel DM, Claessen BE, Råmunddal T, et al.
Improved recovery of regional left ventricular function after PCI of chronic total occlusion in STEMI patients: A cardiovascular magnetic resonance study of the randomized controlled EXPLORE trial. J Cardiovasc Magn Reson 2017;19:53.
Azzalini L, Agostoni P, Benincasa S, Knaapen P, Schumacher SP, Dens J, et al.
Retrograde chronic total occlusion percutaneous coronary intervention through ipsilateral collateral channels: A multicenter registry. JACC Cardiovasc Interv 2017;10:1489-97.
Suzuki Y, Muto M, Yamane M, Muramatsu T, Okamura A, Igarashi Y, et al.
Independent predictors of retrograde failure in CTO-PCI after successful collateral channel crossing. Catheter Cardiovasc Interv 2017;90:E11-8.
Galassi AR, Sianos G, Werner GS, Escaned J, Tomasello SD, Boukhris M, et al.
Retrograde recanalization of chronic total occlusions in Europe: Procedural, in-hospital, and long-term outcomes from the multicenter ERCTO registry. J Am Coll Cardiol 2015;65:2388-400.
Maeremans J, Walsh S, Knaapen P, Spratt JC, Avran A, Hanratty CG, et al.
The hybrid algorithm for treating chronic total occlusions in Europe: The RECHARGE registry. J Am Coll Cardiol 2016;68:1958-70.
Karmpaliotis D, Michael TT, Brilakis ES, Papayannis AC, Tran DL, Kirkland BL, et al.
Retrograde coronary chronic total occlusion revascularization: Procedural and in-hospital outcomes from a multicenter registry in the United States. JACC Cardiovasc Interv 2012;5:1273-9.
Thompson CA, Jayne JE, Robb JF, Friedman BJ, Kaplan AV, Hettleman BD, et al.
Retrograde techniques and the impact of operator volume on percutaneous intervention for coronary chronic total occlusions an early U.S. Experience. JACC Cardiovasc Interv 2009;2:834-42.
Ma JY, Qian JY, Ge L, Fan B, Wang QB, Yan Y, et al.
Retrograde approach for the recanalization of coronary chronic total occlusion: Collateral selection and collateral related complication. Chin Med J (Engl) 2013;126:1086-91.
Ge L, Qian JY, Liu XB, Qin Q, Cui SJ, Yao K, et al.
Retrograde approach for the recanalization of coronary chronic total occlusion: Preliminary experience of a single center. Chin Med J (Engl) 2010;123:857-63.
Kinnaird T, Anderson R, Ossei-Gerning N, Gallagher S, Large A, Strange J, et al.
Vascular access site and outcomes among 26,807 chronic total coronary occlusion angioplasty cases from the British Cardiovascular Interventions Society National Database. JACC Cardiovasc Interv 2017;10:635-44.
Murakami T, Masuda N, Torii S, Ijichi T, Natsumeda M, Fujii T, et al.
The efficacy and feasibility of chronic total occlusion by transradial intervention: A Japanese single-center retrospective study. J Invasive Cardiol 2015;27:E177-81.
Bakker EJ, Maeremans J, Zivelonghi C, Faurie B, Avran A, Walsh S, et al.
Fully transradial versus transfemoral approach for percutaneous intervention of coronary chronic total occlusions applying the hybrid algorithm: Insights from RECHARGE registry. Circ Cardiovasc Interv 2017;10. pii: e005255.
Werner GS, Ferrari M, Heinke S, Kuethe F, Surber R, Richartz BM, et al.
Angiographic assessment of collateral connections in comparison with invasively determined collateral function in chronic coronary occlusions. Circulation 2003;107:1972-7.
Thygesen K, Alpert JS, Jaffe AS, Simoons ML, Chaitman BR, White HD. Third universal definition of myocardial infarction. Eur Heart J 2012;33:2551-67.
Kahn JK, Hartzler GO. Retrograde coronary angioplasty of isolated arterial segments through saphenous vein bypass grafts. Cathet Cardiovasc Diagn 1990;20:88-93.
Morino Y, Abe M, Morimoto T, Kimura T, Hayashi Y, Muramatsu T, et al.
Predicting successful guidewire crossing through chronic total occlusion of native coronary lesions within 30 minutes: The J-CTO (Multicenter CTO registry in Japan) score as a difficulty grading and time assessment tool. JACC Cardiovasc Interv 2011;4:213-21.
Zheng X, Curtis JP, Hu S, Wang Y, Yang Y, Masoudi FA, et al.
Coronary catheterization and percutaneous coronary intervention in China: 10-year results from the China PEACE-retrospective CathPCI study. JAMA Intern Med 2016;176:512-21.
Tanaka Y, Moriyama N, Ochiai T, Takada T, Tobita K, Shishido K, et al.
Transradial coronary interventions for complex chronic total occlusions. JACC Cardiovasc Interv 2017;10:235-43.
Tsuchikane E, Yamane M, Mutoh M, Matsubara T, Fujita T, Nakamura S, et al.
Japanese multicenter registry evaluating the retrograde approach for chronic coronary total occlusion. Catheter Cardiovasc Interv 2013;82:E654-61.
[Table 1], [Table 2], [Table 3], [Table 4]