ORIGINAL CONTRIBUTIONS

Low Rate of Conversion to Transfemoral Approach When Attempting Both Radial Arteries for Coronary Angiography (FULL TITLE BELOW

Antoine Guédès, MD*, Vincent Dangoisse, MD*, Laurence Gabriel, MD, Jacques Jamart, MD, Patrick Chenu, MD, Baudouin Marchandise, MD, Erwin Schroeder, MD
Antoine Guédès, MD*, Vincent Dangoisse, MD*, Laurence Gabriel, MD, Jacques Jamart, MD, Patrick Chenu, MD, Baudouin Marchandise, MD, Erwin Schroeder, MD

FULL TITLE: Low Rate of Conversion to Transfemoral Approach When Attempting Both Radial Arteries for Coronary Angiography and Percutaneous Coronary Intervention: A Study of 1,826 Consecutive Procedures


ABSTRACT: Aims. Despite a proven safety profile, the transradial approach (TRA) for coronary procedures is regarded by many as complicated and the second-choice arterial access, with a high conversion rate to transfemoral access (TFA). This study reports causes of failure and the contemporary success rate of TRA when both radial arteries are attempted first before converting to TFA. Methods. This prospective, single-center study included 1,826 consecutive patients referred for cardiac catheterization, which was performed by two trained operators between January 2005 and June 2007. Procedural data were reported in a specific database. Results. The procedural success rate through TRA (attempting one or both radial arteries) was 98.8%. One hundred and thirty-five radial attempts failed. Inability to puncture or to wire the artery accounted for 52.6% of failures, inability to reach coronary or graft ostia accounted for 20.7% and the remaining failures were related to the inability to reach a contralateral mammary graft. By multivariate analysis, the best predictors for failures were peripheral artery disease (PAD) (odds ratio [OR] 1.8, 95% confidence interval [CI] 1.1–2.8; p = 0.016), bedside clinical assessment of either a “small radial artery” size (OR 2.6, 95% CI 1.4 to 5.0; p = 0.003) or a “difficult access” (OR 2.5, 95% CI 1.3–4.9; p = 0.006). The number of failed attempts regresses annually by about 40% (OR 0.6, 95% CI 0.4–0.8; p

J INVASIVE CARDIOL 2010;22:391–397

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The femoral artery is by far the most commonly used vascular entry site. Coronary interventions for acute coronary syndromes are performed in a “therapeutic” milieu marked by a combination of potent anticoagulant drugs. Not surprisingly, hemorrhagic complications related to the arterial access site have recently emerged as a significant prognostic factor of a worse outcome.1–4 This major problem can be addressed at the source of the problem: the puncture site. Since the demonstration by Lucien Campeau in 1989 of the feasibility and safety of gaining access to the coronary arteries through a percutaneous transradial access (TRA),5 and after Kiemeneij’s original work,6,7 the approach has been adopted by an increasingly large number of centers and operators for both diagnostic and interventional procedures.8 This arterial access is proposed as a bleeding-free access.9–13 The femoral artery is, nevertheless, the first-line vascular approach used due to known fast access allowing immediate intra-aortic balloon support, a large choice of catheter sizes, stronger support for coronary interventions and an easily learned technique. Vascular closure devices permit rapid mobilization and thus more comfort; their use reduces the time required to achieve hemostasis, but they have not been convincingly demonstrated as effective in reducing the rate of bleeding and vascular complications.14–19 In contrast, there are certain beliefs held about the TRA: it is a difficult and time-consuming vascular access with a long learning curve, large catheter sizes cannot be utilized and therefore operators have to deal with less support for interventions, compromising their percutaneous coronary intervention (PCI) success rate; this ultimately results in conversion to a transfemoral access (TFA) or “access failure,” reported to be as high as 7.2%.8,20 With regard to this last argument, we advance the hypothesis that applying the same general strategy as used for TFA (namely, attempting the left femoral artery in the case of a right femoral failed attempt) would equalize the success rate of both techniques. Therefore, we conducted a prospective study offering TRA systematically and for all patients, with the intention to attempt both radial arteries before making a conversion to TFA. We paid particular attention to the causes of each failed attempt.

Methods

From January 2005, every single consecutive patient presenting for left-heart cardiac catheterization, either diagnostic or interventional, elective or urgent, was entered into a prospective study of radial access feasibility by two of the interventionists at our catheterization laboratory (AG/VD). Both operators were already familiar with the TRA. All the procedural features related to the radial attempt were immediately reported within a specifically designed database. The present analysis includes patients and procedures until the end of June 2007. Following protocol, if unable to catheterize by one radial artery, the contralateral radial artery had to be attempted first before moving to a TFA. The contraindications to a radial approach were the absence of pulse or an abnormal Allen’s test at both sides (Barbeau type D)21 and patient refusal. In the case of cardiogenic shock, intra-aortic balloon counterpulsation was initiated before the radial cannulation attempt. By default, the right radial artery was attempted first, but the choice of site was left to the discretion of the operators themselves. For post coronary artery bypass graft (CABG) surgery patients, if a unique mammary artery was used, the ipsilateral radial artery was attempted first; if both needed to be assessed, the patient was informed of the possibility of a bilateral radial approach. In such cases, starting from the right side offered a better chance to reach the left internal mammary artery (LIMA) graft because of anatomical considerations and dedicated catheter availability (4 Fr Outlook IM Catheter, Terumo Corp., Tokyo, Japan). For occasional gastro-epiploic artery graft assessment, the left radial artery approach was initially selected due to the limited length of standard diagnostic catheters. A longer catheter (125 cm) was thereafter available, which meant the celiac truncus could be reached from either the left or right radial artery. Both operators used the same standardized protocol. For artery puncture, the operators’ first intention is to use an over-the-needle technique. For difficult cases, a 0.021 inch nitinol specific wire is preferred, but hydrophilic 0.018 inch or 0.014 inch PCI wires are sometimes helpful. Specific hydrophilic transradial introducers in 4, 5 or 6 French (Fr) sizes are used. Immediately after sheath insertion, intra-arterial heparin (4,000–5,000 I.U.) and 2.5 mg of verapamil are administered. For ad hoc angioplasty, additional heparin is provided. The ascending aorta is first wired with a standard 0.035 inch PTFE wire, but in the case of resistance (most often at elbow level), the wire is quickly exchanged for a 0.035 inch hydrophilic wire, which, in many cases and without fluoroscopy guidance, crosses the corresponding loop at the brachial-radial artery junction. In cases of resistance of the hydrophilic wire, X-ray assistance and dye injection are systematically utilized in order to identify and report the anatomical problem (essentially, large loops and/or small recurrent arteries). For diagnostic coronary angiography, systematic use of the Radial Tig™ 5 Fr catheter (Terumo Corporation, Tokyo, Japan) allows for injection of both arteries as well as eventual saphenous vein grafts and sometimes the ipsilateral mammary artery. When the Radial Tig fails, JR and JL catheters are the second choice. For left coronary artery PCI attempts, extra back-up 3.5 guiding catheters are used (6 Fr for all bifurcation cases requiring kissing balloon). For right coronary artery PCI or saphenous vein graft PCI, specific radial shapes are utilized. The sheath is removed immediately after the procedure, be it diagnostic or interventional: an easy-to-manage compression with the TR-Band™ device (Terumo Corp.) is used in every case, allowing for immediate mobilization. The device does not impede the flow of the ulnar artery, or the hand’s venous return, making the compression very well tolerated. The hand’s arterial supply is again checked by plethysmography before the patient leaves the operating room. The TR-Band is removed when hemostasis is complete, usually after 4–6 hours. Post catheterization, any sudden “bump” or evident hematoma occurring at the forearm level is immediately and vigorously bound. A specific form is completed at the bedside to report vital signs, patient complaints and hemostasis progress. Right-heart catheterization, when requested, is performed through a femoral vein and mobilization is delayed by 3 hours. Following protocol, for each radial artery attempt, the operator must report the following procedural information:
1) Precatheterization radial examination - Modified Allen’s test results (done with plethysmography and saturometer) as described by Barbeau;21 - Evaluation of pulse (“strong,” “normal” or “weak”) and artery size (“large,” “normal” or “small”); - Opinion of the operator about ease of puncture (“easy,” “normal” or “difficult”). 2) Puncture’s technical points - Success of artery puncture (puncture itself and wiring through the needle/cannula (use of special wire or PCI wire is recorded as well); - Success of sheath insertion; - Time to complete the radial access (time to sheath insertion): ≤ 5 minutes; - Ease of puncture: global grade on a scale of 100 (100 being the best). 3) Wires, diagnostic and guiding catheters - Success in reaching coronary or graft ostia, as well as reporting the degree of manipulations required (“easy”, “a few manipulations”, “difficult” or “failed”) and localization of any problems from the radial artery to the coronary or graft ostia; - Occurrence of spasm; - Ease of catheter manipulation: global grade on a scale of 100 (100 being the best); - Number of catheters required. 4) Sheath removal - Ease of removal: global grade on a scale of 100 (100 being the best). 5) Final evaluation: definitions Completing the intended cardiac procedure by radial approach, be it through one or both sides, is defined as a “successful procedure.” In the case of conversion to a TFA, the procedure is defined as an “unsuccessful procedure.” The term “pseudo radial failure” is used if the operator fails to opacify the contralateral mammary artery graft, thus requiring cannulation of the other radial artery for that specific purpose. 6) Post-catheterization follow up.
All events occurring during the hospital stay and related to the vascular site (any hemorrhagic event, hematoma, blood transfusion, vascular surgery, need for additional compression, occurrence of pain, swelling or loss of pulse), and any neurological events are reported independently of operators. Statistical analysis. Categorical and numerical variables were compared between patients by the chi-square test and the Wilcoxon rank sum test, respectively. Logistic regression was performed to study the simultaneous influence of independent variables on radial attempt failure as an outcome using generalized estimating equations (GEE) to take into account the possible number of attempts per patient. A similar logistic regression analysis of the factors related to “hematoma” combined with “ecchymosis” and “redo or prolonged compression” as outcome, with backward selection of variables by the likelihood ratio test was conducted. All statistical tests are two-tailed and a two-sided. A p-value Results Procedural data. From January 2005 to June 2007, 1,826 patients underwent cardiac catheterization starting from a radial access (Table 1). To achieve a 98.8% success rate, 1,939 radial arteries had to be tried: “procedural success” (i.e., no need for conversion to TFA) was obtained for 1,804 patients. The failure rate at the first attempt was 6.8% (124/1,826) for the entire population and 4.9% (80/1,639) when the post-CABG surgery patients were excluded. Figure 1 depicts the ratio of the number of radial arteries to be attempted by patient for the total population and certain prespecified groups. Of the procedures, 1,095 (60%) were only diagnostic, 586 (32%) were ad hoc PCIs and 145 (8%) were elective PCIs. One hundred and eighty-seven (10%) post-CABG surgery patients (at least one mammary artery graft for 177 and both for 73) were studied, with a TRA success rate of 97.9%. Of the 1,939 radial attempts, the right accounted for 1,442 (first radial attempt at the right site for 1,407; 77%) and the left for 497. Table 2 details the distribution of failed radial attempts versus procedural success: access to both radial arteries was necessary in 102 “successful” patients and aborted in 11 “unsuccessful” patients (124 failed attempts). Eleven other “failed” attempts were only unilateral (orthopedic problems precluding use of the contralateral radial artery [n = 1], clinical instability [n = 1], mismatched side of the radial and mammary/gastroepiploic grafts [n = 2], absence of contralateral radial pulse [n = 4], no reported reasons and thus protocol violation [n = 3]). The Allen’s test was abnormal (Barbeau types C and D) for 22 right and 11 left hands, respectively (both sides for only 2 patients), but the use of Barbeau type C radial arteries in 21 attempts was uncomplicated. Among these patients, 4 transradial attempts failed. During the study period, but not included in this analysis, the two operators performed 33 additional PCIs by the TFA: patients arrived with the femoral sheath still in place after their angiogram had been done in another hospital. In the case of two post-CABG patients, TFA was done in early 2005 with no clear justification for not attempting the TRA (protocol violation). Due to planned surgery for an arteriovenous fistula, TRA was not offered to 1 renal failure patient. The operators had to handle 4 cases of bilateral absence of a radial pulse, of which two were managed by TFA. The remaining 2 had severe peripheral artery disease, no femoral pulses and were first managed by TRA, with success in 1 case (“protocol violation” too, in some way). The remaining patient was finally catheterized via the transbrachial artery after failure of both radial attempts. These 2 patients are included in the present analysis. Bedside clinical evaluation identified the radial access of 253 patients (13.8%) as “difficult” due to a weak pulse, “small vessel” size, or both. This assessment was more frequent for females (28.3 versus 7.6%; p Causes of failed radial attempts. Causes can be categorized into four groups (Figure 2): - inability to puncture the artery itself (n = 17, right 12), inability to advance the wire through the needle (n = 48, right 32) or inability to place the sheath over the wire (n = 6); these causes account for 52.6% of failures; - inability to advance the wire or catheter through the brachial (n = 11), the axillary (n = 3) or the innominate artery (n = 1) accounted for 11.1% of failures; • inability to reach coronary or graft ostia (n = 13) after reaching the ascending aorta accounted for 9.6% of failures; • inability to cannulate the contralateral mammary artery (n = 36) accounted for 26.7% of failed approaches. Operator 1 performed 20 cases of combined LIMA/RIMA (right internal mammary artery) in CABG patients compared with 53 for Operator 2; “pseudo-radial failure” was 50% for both operators. During the first year of the study (2005), 54 of 656 attempts failed (7.6%), but this rate dropped to 29 of 763 (3.7%) in 2006 and to only 14 of 425 (3.2%) in 2007. By univariate analysis of the prespecified clinical characteristics, only gender was predictive of the need for a non-radial access (procedural failure) (female, 2.1% versus 0.9%; p = 0.036); diabetes was of borderline significance (p = 0.099). Table 3 shows the results of the first step of the regression analysis performed. The failed attempts were analyzed, taking into account, or not, the failed attempts due to an unreached contralateral mammary artery. After the exclusion of such “pseudo-radial failure”, the four main variables linked to a failed radial attempt are: the year of procedure (operator experience) (p Complications. For the 1,826 patients, complications (excluding the major cardiac events which were not prespecified endpoints) were limited and most were benign apart from 1 definite stroke: 38 ecchymosis (2.08%),26 small hematoma (1.42%),51 hematoma (2.79%),29 prolonged compression (1.59%),29 local swelling (1.59%)26 and local pain (1.42%). Four possible and 2 definite transient ischemic attacks (TIAs) (0.1%) were also reported, and the only vascular surgery addressed a femoral pseudoaneurysm (unsuccessful radial procedure); a second case of femoral pseudoaneurysm was treated with thrombin injection. Only one transfusion was recorded as being procedure-related. No hand ischemia occurred. A logistic regression analysis performed for “hematoma” combined with “swelling” (70 occurrences, 3.8%) with the same variables and the variable “use of inhibitors of glycoprotein IIb/IIIa receptors” identified female gender (OR 2.4, 95% CI 1.4–3.9; p = 0.001) and age (> 80 years) (OR 1.9, 95% CI 1.0–3.7; p = 0.040) as predisposing factors for such outcomes. Grouping ecchymosis, hematoma and prolonged compression (n = 117, 6.4%) sorted out female gender (p Discussion A TRA procedural success rate as high as 98.8% can be expected when applying the same strategy as for femoral access, namely systematic use of the contralateral radial artery in the case of failure on the initial side. When there is failure on one side, there is a 78% chance of success through the other. This global TRA success rate is at least equivalent to the rate observed by the femoral route. Thus, this finding of a very low conversion rate to TFA confirms our principal hypothesis. Difficult cases caused by puncture problems account for only 8.4% of procedures, and only 6.1% of procedures were recorded as difficult due to catheter manipulation. It is interesting to note that such a success rate is obtained despite anticipated difficulty (preprocedure evaluation) for 13.8% of the global population and for 28% of females. In our study, the bedside clinician’s evaluation (access looked “difficult” and/or size of the radial artery looked “small”), combined with the history of PAD, allowed prediction of difficult cases. The study also shows that failures are mainly related to puncture (52.6%). It is easy to relate the negative predictive factor “small artery” with the fact that in the series of 1,939 radial attempts, 52.6% of failures were related to the two initial steps: puncture or, more frequently, wiring the artery through the needle; this task is obviously more difficult for small vessels. Moreover, a history of PAD can be easily linked with the 20.7% of failures (that are not directly related to the radial artery cannulation and to the mammary graft problem): the cause here is a diseased vascular bed, with occluded or tortuous and rigid large vessels. Reaching an ipsilateral mammary artery from a TRA allows a highly selective injection of the graft and of its distal bed, thus providing valuable clinical information. Failure to reach the contralateral mammary artery (“pseudo radial failure”) is easy to understand given the anatomy of large vessels at the aortic arch level and it is, to some extent, a technical problem. In fact, new catheters with improved characteristics (coating, shape and/or torque or pushability) will some day overcome this particular challenge and shorten the time required for this particular task. In order to reduce X-ray exposure, our actual policy is to limit the fluoroscopy time allowed to 5 minutes when attempting a contralateral mammary artery. Our data confirm that overweight patients are not difficult cases when the radial approach is used; the technique performs as well as for the population in general, including an uneventful post-catheterization course. In terms of safety for patients, failed radial attempts that occur most of the time at needle level cannot lead to any serious clinical consequences. The study confirms the reality of a long learning curve: even in the case of already trained operators, the year of procedure is a strong predictive factor of radial success (p 22,23 Vascular injury is more frequently seen in an aging population, as older arteries are more “fragile.” This is not the first study to show that female vessels are more prone to vascular injury when catheterized. Thus, our study associating female gender (p = 0.001) and age > 80 years (p = 0.040) with a higher rate of hematoma should encourage very soft and gentle manipulation for both elderly patients and females. The findings that with time, there is a reduced rate of occurrence for the combination of ecchymosis, hematoma and recompression could also be viewed as the sign for the existence of a learning curve for the nursing staff taking care of patients after TRA and not only a sign of operator performance. This should mandate some teaching at this level when starting a TRA program. It is possible that a proportion of the very low rate of vascular- and bleeding-related problems are due to the specifically shaped hydrophilic radial sheaths and also to the less traumatic and very elegant compression device used in each case; this device limits the vessel’s compression both in time and in intensity. Study limitations. This large series of consecutive, non-selected patients embraces a very wide variety of cases, urgent or elective, as seen in daily practice. This study was not designed to compare in a randomized fashion and for a given population of patients the feasibility of the radial versus the femoral approach, but rather to identify problems related to the TRA. The ideal sizing of guiding catheters for coronary angioplasty is still a matter of debate. Although some radial arteries will eventually accept 7 Fr catheters or larger, in this series we never needed a lumen larger than that provided by the actual class of 6 Fr guiding catheters, including for successful CTO PCIs and for bifurcations requiring the kissing-balloon technique.

Conclusions

When applying a strategy of systematic contralateral radial artery attempt should the initial one fail, we demonstrate that any percutaneous coronary diagnostic or interventional procedure can be performed via the radial route with a high success rate and an extremely low complication rate with regard to vascular or local bleeding problems. There is no specific population of patients that is unlikely to be able to take advantage of the technique in terms of feasibility or safety. Contemporary interventional cardiology practice, which predominantly addresses acute coronary syndromes, thus requiring use of potent anti-clot medications, would happily welcome this technique.

References

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From the University of Louvain (UCL), Division of Cardiovascular Medicine, Cliniques Universitaires de Mont-Godinne, Yvoir, Belgium. *Drs. Guédès and Dangoisse contributed equally to this work. The authors report no conflicts of interest regarding the manuscript content herein. Manuscript submitted February 16, 2010, provisional acceptance given March 29, 2010, final version accepted June 2, 2010. Address for correspondence: Antoine Guédès, MD, Avenue Gaston Therasse 1, Cliniques Universitaires de Mont-Godinne, 5530 Yvoir, Belgium. E-mail: antoine.guedes@uclouvain.be