Transradial Coronary Artery Procedures: Tips for Success

Login or register to view PDF.
Abstract

Historically, the majority of coronary procedures have been performed via the femoral artery. However, since the inception of the transradial approach, a number of studies have confirmed that this technique is associated with a significant reduction in vascular complications, equivalent procedure times and radiation exposure to femoral procedures, the ability to perform complex coronary interventions, early ambulation and patient preference. Over the last decade, this has led to an exponential rise in the use of the transradial access site, with several potential technical challenges becoming increasingly recognised. However, with greater experience and technological advancement these potential obstacles may be overcome. The following review highlights the potential challenges and suggests several tips to assist transradial operators with recognising and overcoming these challenges.

Disclosure
The authors have no conflicts of interest to declare.
Correspondence
Kully Sandhu, Cardiology Registrar, Cardiology Department, Royal Stoke University Hospital, University Hospitals of North Midlands, Stoke-on-Trent, ST4 6QG, UK. E: ksandhu@hotmail.com
Received date
25 October 2016
Accepted date
10 April 2017
Citation
Interventional Cardiology Review 2017;12(1):18–24
DOI
https://doi.org/10.15420/icr.2017:2:2

Percutaneous revascularisation has become the cornerstone of ischaemic heart disease management.1,2 Historically, coronary angiography and intervention was predominantly performed via the common femoral artery.3 However, this procedure has an associated 1.5–9.0 % risk of complications, most of which are related to bleeding at the femoral access site.4 Despite a significant reduction in the incidence of major femoral bleeding complications during 1994 to 2005 from 8.4 % to 3.5 %, respectively,5 related to technological advancement (including a reduction in size of interventional devices and, controversially, the introduction of vascular closure devices), these major complications remain important.6–9 Multiple large studies have demonstrated a two- to eightfold increase in mortality rate in patients with acute coronary syndrome (ACS) who experienced major bleeding following percutaneous coronary intervention (PCI).5,10–13

Campeau reported the first contemporary use of transradial access for diagnostic procedures in 1989;14 this was shortly followed by reports of the first transradial angioplasty.15,16 Several early studies reported a significant reduction in vascular complications for transradial procedures compared with the transfemoral approach.17–19 These early studies raised interest in the transradial access site as a viable and attractive alternative to femoral access.20–22 There followed larger, multicentre, prospective, randomised trials designed to overcome any potential bias of earlier single-centre trials and retrospective meta-analyses.

The Radial Versus Femoral Access for Coronary Angiography and Intervention in Patients with Acute Coronary Syndromes (RIVAL) study set out to determine whether radial access was superior to femoral access in patients with ACS undergoing coronary angiography and angioplasty.23 This large randomised, worldwide multicentre trial of 7,021 patients demonstrated that transradial procedures were associated with a 60 % reduction in vascular complications when compared with the femoral approach, but no significance difference in rates of death, MI, stroke or major bleed. However, the RIVAL primary PCI (PPCI) in ST elevation MI (STEMI) sub-analysis found that the radial artery approach was associated with a significant reduction in the rate of 30-day all-cause mortality.24

These findings led to the Minimizing Adverse Haemorrhagic Events by Transradial Access Site and Systemic Implementation of AngioX (MATRIX) trial, a large randomised, multicentre, superiority trial comparing transradial versus transfemoral approach in 8404 patients with ACS.27 The study found no reduction in the rate of MI, stroke, or non-coronary artery bypass graft-related major bleeding at 30 days, but a 63 % reduction in the risk of vascular-access complications was seen in the transradial group. The transradial approach was also found to reduce net adverse clinical events, and all-cause mortality and major bleeding rates. This reduction in the rates of allcause mortality and bleeding occurred in all patients with ACS and was not limited to patients with STEMI, as in the aforementioned RIVAL study.

Several early studies reported a reduction in mortality rates in patients undergoing transradial access for STEMI.28–31 These studies paved the way for the Radial Verses Femoral Randomized Investigation in ST elevation Acute Coronary Syndrome (RIFLE-STEACS) trial.

This prospective, randomised study evaluated transradial versus transfemoral arterial access in patients with STEMI. The study enrolled 1,001 patients across four Italian centres and found not only a 47 % reduction in the rate of access-site-related bleeding complications, but also a reduction in the rate of cardiac death and hospital stay with transradial procedure.25 These findings were verified by a meta-analysis of 12 studies including 5,055 patients recommended radial approach for patients with STEMI undergoing PPCI.26

The reduction in vascular complications has also been highlighted in other potential high-risk groups including obese patients,32 octogenarians33,34 and female patients.35

Further advantages of a transradial approach include immediate ambulation, as opposed to bed rest after femoral procedures. Reduced post-procedure nursing care, reduced hospital stay and, therefore, cost, with an overwhelming patient preference for transradial angiography are all well-described additional advantages.36–42

Findings from these studies have led to the recommendation for use of the radial artery approach in both patients with STEMI43 and non-STEMI.44

Opponents of radial access have cited an associated learning curve45 with adopting the transradial approach resulting in longer procedural time and increased radiation exposure.46 However, a meta-analysis found the difference in radiation exposure between transradial and transfemoral approaches to decrease by >75 % over a 20-year period, and that the clinical benefits of transradial access outweighed any small observed difference in radiation exposure.47 In addition, higher-volume radial operators were shown to have shorter procedural and fluoroscopy times. Lower-volume operators achieve a reduction in procedural and fluoroscopy times as their procedural experience increases.48 Similarly, a sub-analysis of the multicenter RIVAL study found no significant differences in radiation exposure between either femoral or radial access for the entire cohort. However, a modest, but significant, increase in fluoroscopy time in radial cases performed in a low- to intermediate-volume center, but not in high-volume centers. Furthermore, a sub-analysis and multivariate analysis found the highest radial volume centres and operators had the lowest radiation exposure.49

Finally, Burzotta et al. found that the case volume required to overcome the learning curve was relatively short – 50–80 transradial procedures.50 As a result of these studies, operators in the UK are increasingly adopting radial access (see Figure 1).22

Tips for Successful Transradial Coronary Artery Procedures

Know Your Patient

The first tip begins outside the catheter laboratory. A full and detailed explanation of the procedure should be provided not only as a consenting exercise, but also to decrease patient anxiety. It is important to obtain details of any significant patient comorbidity, allergies, previous coronary artery bypass grafts and or PCI. In patients with previous PCI, it is important to determine which arterial access approach was used, and if any difficulties were encountered including switching access site or post-procedural bleeding. Previous angiographic images should be reviewed, if possible, to identify any pre-existing coronary artery disease or procedural difficulties encountered, and to ascertain the presence of patent grafts and any vascular abnormalities or tortuous vasculature. Relevant blood tests including haemoglobin, renal function and troponin levels should also be reviewed. The Allen’s test, once thought to be pivotal in the assessment of patiens suitability for radial angiography, is now recognised to be of little value due to ulnar–palmer collateralisation.51 Therefore, the routine use of Allen’s test is no longer recommended within the author’s institute.

Figure 1: Percentage Increase in the Use of Transradial Access Approach for Coronary Intervention by Year

Open in new tab
Open ppt

Venous Access

All patients should have intravenous access, preferably in the contralateral arm to the side of transradial approach, allowing administration of medication including intravenous saline or sedatives. Radial artery spasm has become an increasingly recognisable phenomena52 seen in 10–15 % of reported cases of transradial procedures.53,54 Catecholamine release due to anxiety increases risk of radial artery spasm; therefore, the patient should be as relaxed as possible. Sedation has often been used in attempt to prevent radial artery spasm. A study of 2,013 patients who were randomised to receive fentanyl plus midazolam or no sedation found a significant reduction in spasm, and the number needed to treat to avoid one case of radial artery spasm was 18.55 The crossover rate to femoral artery was 34 % lower in the group given fentanyl and midazolam. The results of this study supported the use of pre-procedural sedation. However, the study was criticised for incomplete reporting.56 A large multicentre and worldwide study found not only a wide geographic variation in the use of sedation, but also that 58.3 % of operators did not routinely use sedation.21 At present, there are insufficient data to recommend routine use of sedation.

Left or Right Radial Artery Access

Transradial angiography and PCI are predominantly performed from the right radial artery due to cardiac catheter laboratory set, operator comfort and preferences.

Traditionally, there had been concerns about radiation dose and success rates of the left radial approach. However, the (Randomized Evaluation of Vascular Entry Site and Radiation Exposure) REVERE trial found no significant difference in radiation dose in 1,500 patients undergoing either femoral, right or left radial artery approaches.57 The study also found a reduction in radiation dose in experienced radial and femoral operators.58,59 These studies also found no difference in contrast load, number of catheters used or success rates.58,59 Major adverse cardiac and cerebrovascular event rates have also been found to be similar.58,59 Norgaz et al. attributed shorter fluoroscopy times from left radial artery approach to a threefold higher incidence of subclavian tortuosity, as well as a higher incidence of radial loops with right radial access.59

Table 1: Classification and Rate of Radial Artery Anomaly and Associated Rates of Procedural Failure65

Open in new tab
Open ppt

Further advantages of using the left radial artery approach include significantly shorter learning curve and progressive reduction in fluoroscopic and arterial cannulation times when compared with right radial artery approach.60 Therefore, the left radial approach is both feasible and safe in clinical practice.

The left radial artery approach may also be used post coronary artery bypass graft if patients have had a left internal mammary artery (LIMA) graft to the left anterior descending (LAD) artery. This is because cannulation of the LIMA to LAD graft has been associated with a failure in 27 % of cases if performed from the right radial artery.61 The presence of a retro-oesophageal origin may either preclude or render more complex cannulation of the coronary arteries from the right radial artery, whereas a left radial approach may prove to be easier and more successful. The patients arm may be placed on an arm board anchored under the patient either at 80° or alongside the patient depending on operator preference. A folded bed sheet or specialised arm board devices placed under the wrist allows hyperextension of the wrist. This allows not only increased support, but also exposure of the radial artery. The wrist is then cleaned, draped and infiltrated with local anaesthesia.

Radial Artery Puncture Kits and Spasmolytics

A number of radial access kits are currently commercially available, including the bare-metal Micropuncture® system (Cook Medical) and a Glidesheath Slender hydrophilic-coated introducer sheath (Terumo). The choice of puncture kit is at the discretion of the operator; however, familiarity of both kits is advisable. Irrespective of the puncture system used, the radial artery should be punctured at 30–45° to the horizontal and 2 cm proximal to the radial styloid process, to minimise the risk of introducing the sheath into a smaller diameter distal radial artery. A small skin incision may be performed while the guide wire is in situ, allowing easier introduction of the sheath and further reducing any distress or pain experienced by the patient. Once the radial sheath has been introduced spasmolytics are often administered to try to prevent radial artery spasm.62 A meta-analysis found that 5 mg of verapamil or verapamil in combination with nitroglycine had the lowest rates of radial artery spasm.54 In a survey across 75 countries, the majority (85.9 %) of operators used vasodilators prophylactically with verapamil being the most commonly used agent (75.3 %), either alone or in combination with a number of other agents.21

The use of prophylactic vasodilator anti-spasmolytic cocktails is largely operator preference based on the operator’s own common practice rather than based on rigorous placebo-based clinical trials. The rate of radial artery spasm varies widely in different trial and this may be attributed due to a lack of consensus of the definition of radial artery spasm. This, in turn, limits inter-trial comparisons and, therefore, any meta-analysis. However the use of anti-spasmolytic agents have been questioned. Technical advancements such as a reduction in the diameter and the addition of hydrophilic coating of radial introducer sheaths both reducing risk of radial artery spasm. Geographic variation of the use of anti-spasmolytics has been observed, and up to 72.2 % of Japanese operators do not use anti-spasmolytics.21 The study results indicate that the preventative use of anti-spasmolytics may not be as important as once thought.

Radial artery spasm has been found to be a rare event after a learning curve (1.7 %) and use of verapamil 5 mg showed no significant difference in investigated endpoints, including access site conversion, radial artery spasm or subjective pain, compared with placebo.63 These findings led to further questioning of the use of verapamil in high-volume operators. The authors concluded that prophylactic vasodilators showed no advantage.63 The omission of vasodilators may be clinically relevant by avoiding adverse effects and not precluding radial angiography in patients with known contraindications to vasodilators.64

Radial Artery Anomalies and Tortuosity

A landmark study of 1,540 consecutive patients found that radial artery anatomy anomalies are a relatively common finding occurring in 13.8 % (n=212) of patients undergoing transradial coronary procedures.65 Radial artery anomalies were associated with a significant incidence of procedural failure (14.2 versus 0.9 % in non-anomalous radial arteries; see Table 1). Despite this, the overall procedural success was found to be 96.8 %, with only 1 % (n=5) having vascular complications, all managed conservatively without any ischaemic sequelae. The authors, therefore, recommended imaging of the radial artery after introducing sheath insertion.

Certain radial artery anomalies (such as large-diameter radial loops) may be difficult to overcome and an alternative vascular access may be required. However, there are several available techniques for overcoming simpler anomalies such as radial tortuosity. Balloonassisted tracking is a technique that may be used to overcome radial tortuosity, spasm or loops.66,67 A regular 0.014” hydrophilic coronary angioplasty wire is passed through the difficult area under fluoroscopy. Then a diagnostic or guide catheter is loaded with a standard non-compliant balloon positioned half protruding beyond the tip of the catheter. A 5 Fr catheter will accommodate a 2.0 mm balloon, whereas a 6 Fr guide may require a 2.5 mm diameter balloon. Once correctly positioned, the balloon is inflated to 8–10 atmospheres. The catheter–balloon delivery system is then loaded onto and passed along the 0.014” hydrophilic coronary angioplasty wire. The balloon– catheter delivery system creates a soft tapered edge straightening the radial tortuosity and facilitating catheter passage through the loops or areas of spasm, limiting further radial trauma and pain. This manoeuvre is performed under fluoroscopic guidance (see Figure 2). Once the catheter has reached the ascending aorta the 0.014” hydrophilic coronary angioplasty wire and balloon catheter may be changed to a standard 0.035” guide wire, providing greater support to position the catheter into the aorta root. An exchange length J-tip (260 cm) guidewire is then used to exchange catheters to avoid loss of radial access.

Figure 2: Balloon-Assisted Tracking

Open in new tab
Open ppt

A simpler method is passing a regular 0.014” hydrophilic coronary angioplasty wire cautiously along the tortuosity and secured within the subclavian artery. This often straightens out the radial artery. A 5 Fr diagnostic multipurpose catheter is then loaded onto the proximately positioned wire. The multipurpose catheter decreases the risk of the radial artery wall shearing and the damage that occurs with more angulated catheters such as the Judkins or Amplatzer® catheters. Cautious advancement under fluoroscopic guidance is mandatory. First, to avoid engagement into small branches and to ensure the catheter is smoothly traversing to the head and neck vessels and, second, to prevent catheter kinking within the radial artery causing intense spasm and pain to the patient (see Figure 3A–D). Once the catheter has reached the subclavian artery just proximal to the end of the regular 0.014” hydrophilic coronary angioplasty wire, the coronary angioplasty wire is then exchanged with a standard J-tip (260 cm) exchange wire. The exchanged wire provides greater support for the catheter. The multipurpose catheter is then withdrawn ensuring the exchange length (260 cm) guidewire remains positioned within the subclavian artery. A standard diagnostic or guide catheter may then be loaded onto the J-tip exchange length (260 cm) guidewire, and both passed under fluoroscopic guidance to the aortic root in standard manner. The coronary arteries are then cannulated. All subsequent catheter changes are performed via the J-tip (260 cm) guidewire avoiding the need to re-cross areas of difficult anatomy.

Similarly, the above techniques may also be applied in the presence of tortuous brachial or subclavian arteries. Deep inspiration with breath holding may allow further negotiation of subclavian artery tortuosity by modifying the angulation of the brachiocephalic trunk. The optimal view for assessing the ascending aorta is in the left anterior oblique projection at 30°. This projection limits superposition of different segments of the aorta and opens out the aortic arch. Recognition of the position of the guidewire in either ascending or descending aorta is then made possible. If the guidewire repeatedly enters the descending rather than ascending aorta a diagnostic 5 Fr or 6 Fr JR4 catheter may be advanced with great care not to extend beyond the guidewire. On reaching the aorto– brachiocephalic or aorto–subclavian junction for right and left radial artery access, respectively, the catheter can be angulated towards the ascending aorta facilitating wire access. An exchange length (260 cm) guidewire should be used if further catheter exchanges are required.

Figure 3: Use of a Regular 0.014” Hydrophilic Coronary Angioplasty Wire to Straighten a Radial Loop

Open in new tab
Open ppt

Finally, all catheters should always be withdrawn over a 0.035” guidewire even in non-tortuous radial arteries. This manouvre avoids any forceful manipulation or catheter tip induced trauma that may cause catheter kinking and radial artery spasm or avulsion.68,69

Radial Artery Diameter

Radial artery diameter may potentially limit the maximum size of radial artery introducer sheath, especially as the external diameter of the introducing sheath is 2 Fr larger than its internal diameter.70 The ideal ratio of inner diameter of radial artery to sheath outer diameter has been found to be 0.9.71 Operators should avoid using sheath diameters greater than the radial artery diameter.72 The smaller-diameter hydrophilic introducer sheaths are associated with a reduction in both incidence of radial artery spasm73,74 and pain experienced by patients.71 Therefore, radial artery access had been thought to preclude larger-bore guide catheters required for more complex lesions.

There are several approaches that may overcome this potential technical challenge. The first is the use of the Glidesheath Slender® (Terumo) introducer sheath, which has a thin wall providing an inner diameter compatible with 6 Fr catheters and an outer diameter corresponding to 5 Fr sheath, allowing passage of large-bore guide catheters. These introducer sheaths have been reported to have high success rates with a significant reduction in radial artery occlusion and radial artery spasm.75,76

Sheathless guide catheters negate the use of radial introducer sheaths. This technique has been shown to be both safe and effective in both elective and primary PCI for patients with STEMI.77 However, the main advantage is the ability to allow transradial passage of the large-bore 7 or 8 Fr guide catheters that may be required for complex coronary interventions.70 The radial artery is cannulated with a standard 5 or 6 Fr radial artery sheath. Diagnostic coronary angiography may be performed in the usual maner with either 5 or 6 Fr diagnostic catheters. If diagnostic images indicate that coronary intervention is required with a large-bore guide catheter then the 5 or 6 Fr diagnostic catheter is removed over a J-tip (260 cm) guidewire positioned and secured in the ascending aorta. The introducer sheath is then also removed cautiously over the J-tip (260 cm) guidewire. Pressure is then applied onto the radial artery access site once the introducer sheath is removed. A 7 or 8 Fr standard guide catheter with a 5 Fr multipurpose catheter extending beyond the tip provides a smooth transition from wire to catheter, and is loaded on to the J-tip (260 cm) guidewire. This delivery system is then passed into the ascending aorta under fluoroscopic guidance. The inner 5 Fr multipurpose catheter is then removed leaving the 7 or 8 Fr guide within the ascending aorta ready to be manoeuvred in the standard way to cannulate the coronary artery. On completion of the intervention, the guide catheter is taken out using the standard over-the-wire technique and a haemostatic compression device is placed.78

A modified version adopts the balloon-assisted technique described above for tortuous radial artery. A regular 0.014” hydrophilic coronary angioplasty wire is passed under fluoroscopic guidance through a standard 5 or 6 Fr radial introducer sheath to the ascending aorta. The introducer sheath is removed over the hydrophilic coronary angioplasty wire. A 7 Fr introducer without the sheath is loaded and passed along the coronary angioplasty wire to ensure a passage has been made into the radial artery. The delivery system is then loaded onto and passed along the hydrophilic coronary angioplasty wire to the ascending aorta. The delivery system consists of a largebore guide catheter with a balloon catheter positioned so that it protrudes partially outside the guide catheter. The balloon is then inflated to low pressure, 6–8 atmospheres. The delivery system creates a soft tapered edge that passes within the radial artery. Once the delivery system has reached the ascending aorta the balloon is deflated and, along with the 0.014” hydrophilic coronary angioplasty wire, may be changed to a standard 0.035” guidewire providing greater support. The coronary artery is then cannulated the standard way.

Radial artery occlusion

One of the advantages of the radial artery is its superficial location, which allows safe and effective haemostasis by compression. This has led to many haemostatic compression devices becoming available, including TR Band ® (Terumo), RadiStop™ (St. Jude Medical), RADstat® (Merit Medical Systems) and Helix® band (Vascular Perspectives). The most frequent complication of radial procedures is radial artery occlusion (RAO). The technique of patent haemostasis has been shown to significantly reduce radial artery occlusion at 30 days and, in the opinion of the authors, should be standard practice.79,80 RAO is usually asymptomatic due to ulnar–palmar collateralisation vascular blood supply of the hand. However, RAO precludes the use of radial artery access in any future coronary interventions. Procedural duration, arterial diameter-to-sheath ratio, compression time and pressure all have been shown to be risk factors for RAO.80 Heparin has been shown to significantly reduce rates of RAO, with a linear relationship observed between heparin dose and rate of RAO.81 This has led to most operators administering 5,000 IU of heparin or 70 IU/kg intra-arterial via the radial sheath. Heparin may also be given intravenously, with no difference in RAO whether given intra-arterially or intravenously.82 However, there are no current recommendations on heparin dose in patients taking oral anticoagulation or receiving platelet glycoprotein IIb/IIIa inhibitors (abciximab, eptifibatide, tirofiban) or direct thrombin inhibitor use (bivalirubin).

Finally, radial artery spasm has also been identified as a potential risk factor for RAO.73 However, a meta-analysis found no data to assess any link between pharmacological prevention of RAS and prevention of RAO, further highlighting the importance of preventing RAS.54

Conclusion

There has been an exponential growth in the use of transradial coronary artery procedures over the last two decades. This increased use of transradial procedures has led to a number of potential technical challenges becoming recognised. However, with increasing experience many new approaches are now becoming available to overcome these potential challenges to transradial coronary procedures.

References
  1. Levine GN, Bates ER, Blankenship JC, et al. 2015 ACC/AHA/ SCAI focused update on primary percutaneous coronary intervention for patients with ST-elevation myocardial infarction: an update of the 2011 ACCF/AHA/SCAI guideline for percutaneous coronary intervention and the 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction. J Am Coll Cardiol 2016;67:1235–50.
    Crossref | PubMed
  2. Amsterdam EA, Wenger NK, Brindis RG, et al. 2014 AHA/ ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2014;64:e139–228. 
    Crossref | PubMed
  3. Moscucci M. Grossman & Baim’s Cardiac Catheterization, Angiography, and Intervention. 8th edition. Philadelphia: Lippincott Williams and Wilkins, 2013.
  4. Nasser TK, Mohler ER 3rd, Wilensky RL, et al. Peripheral vascular complications following coronary interventional procedures. Clin Cardiol 1995;18:609–14.
    Crossref | PubMed
  5. Doyle BJ, Ting HH, Bell MR, et al. Major femoral bleeding complications after percutaneous coronary intervention: incidence, predictors, and impact on long-term survival among 17,901 patients treated at the Mayo Clinic from 1994 to 2005. JACC Cardiovasc Interv 2008;1 :202–9.
    Crossref | PubMed
  6. Applegate RJ, Sacrinty MT, Kutcher MA, et al. Trends in vascular complications after diagnostic cardiac catheterization and percutaneous coronary intervention via the femoral artery, 1998 to 2007. JACC Cardiovasc Interv 2008;1:317–26.
    Crossref | PubMed
  7. Sesana M, Vaghetti M, Albiero R, et al. Effectiveness and complications of vascular access closure devices after interventional procedures. J Invasive Cardiol 2000;12:395–9.
    PubMed
  8. Dauerman HL, Rao SV, Resnic FS, et al. Bleeding avoidance strategies. Consensus and controversy. J Am Coll Cardiol 2011;58:1–10.
    Crossref | PubMed
  9. Marso SP, Amin AP, House JA, et al. Association between use of bleeding avoidance strategies and risk of periprocedural bleeding among patients undergoing percutaneous coronary intervention. JAMA 2010;303:2156–64.
    Crossref | PubMed
  10. Eikelboom JW, Mehta SR, Anand SS, et al. Adverse impact of bleeding on prognosis in patients with acute coronary syndromes. Circulation 2006;114:774–82.
    Crossref | PubMed
  11. Manoukian SV, Feit F, Mehran R, et al. Impact of major bleeding on 30-day mortality and clinical outcomes in patients with acute coronary syndromes: an analysis from the ACUITY Trial. J Am Coll Cardiol 2007;49:1362–8.
    Crossref | PubMed
  12. Yatskar L, Selzer F, Feit F, et al. Access site hematoma requiring blood transfusion predicts mortality in patients undergoing percutaneous coronary intervention: data from the National Heart, Lung, and Blood Institute Dynamic Registry. Catheter Cardiovasc Interv 2007;69:961–6.
    Crossref | PubMed
  13. Rao SV, Jollis JG, Harrington RA, et al. Relationship of blood transfusion and clinical outcomes in patients with acute coronary syndromes. JAMA 2004;292:1555–62.
    Crossref | PubMed
  14. Campeau L. Percutaneous radial artery approach for coronary angiography. Cathet Cardiovasc Diagn 1989;16:3–7.
    Crossref | PubMed
  15. Kiemeneij F, Laarman GJ. Percutaneous transradial artery approach for coronary stent implantation. Cathet Cardiovasc Diagn 1993;30:173–8.
    Crossref | PubMed
  16. Kiemeneij F, Laarman GJ. Percutaneous transradial artery approach for coronary Palmaz-Schatz stent implantation. Am Heart J 1994;128:167–74.
    Crossref | PubMed
  17. Kiemeneij F, Laarman GJ, Odekerken D, et al. A randomized comparison of percutaneous transluminal coronary angioplasty by the radial, brachial and femoral approaches: the access study. J Am Coll Cardiol 1997;29:1269–75.
    Crossref | PubMed
  18. Mann T, Cubeddu G, Bowen J, et al. Stenting in acute coronary syndromes: a comparison of radial versus femoral access sites. J Am Coll Cardiol 1998;32:572–6.
    Crossref | PubMed
  19. Jolly SS, Amlani S, Hamon M, et al. Radial versus femoral access for coronary angiography or intervention and the impact on major bleeding and ischemic events: a systematic review and meta-analysis of randomized trials. Am Heart J 2009;157:132–40.
    Crossref | PubMed
  20. Feldman DN, Swaminathan RV, Kaltenbach LA, et al. Adoption of radial access and comparison of outcomes to femoral access in percutaneous coronary intervention: an updated report from the national cardiovascular data registry (2007-2012). Circulation 2013;127:2295–306.
    Crossref | PubMed
  21. Bertrand OF, Rao SV, Pancholy S, et al. Transradial approach for coronary angiography and interventions: results of the first international transradial practice survey. JACC Cardiovasc Interv 2010;3:1022-31.
    Crossref | PubMed
  22. Mamas MA, Fraser DG, Ratib K, et al. Minimising radial injury: prevention is better than cure. EuroIntervention 2014;10:824–32.
    Crossref | PubMed
  23. Jolly SS, Yusuf S, Cairns J, et al. Radial versus femoral access for coronary angiography and intervention in patients with acute coronary syndromes (RIVAL): a randomised, parallel group, multicentre trial. Lancet 2011;377:1409–20.
    Crossref | PubMed
  24. Mehta SR, Jolly SS, Cairns J, et al. Effects of radial versus femoral artery access in patients with acute coronary syndromes with or without ST-segment elevation. J Am Coll Cardiol 2012;60:2490–9.
    Crossref | PubMed
  25. Romagnoli E, Biondi-Zoccai G, Sciahbasi A, et al. Radial versus femoral randomized investigation in ST-segment elevation acute coronary syndrome: the RIFLE-STEACS (Radial Versus Femoral Randomized Investigation in ST-Elevation Acute Coronary Syndrome) study. J Am Coll Cardiol 2012;60:2481–9.
    Crossref | PubMed
  26. Karrowni W, Vyas A, Giacomino B, et al. Radial versus femoral access for primary percutaneous interventions in ST-segment elevation myocardial infarction patients: a meta-analysis of randomized controlled trials. JACC Cardiovasc Interv 2013;6:814–23.
    Crossref | PubMed
  27. Valgimigli M, Gagnor A, Calabro P, et al. Radial versus femoral access in patients with acute coronary syndromes undergoing invasive management: a randomised multicentre trial. Lancet 2015;385:2465–76.
    Crossref | PubMed
  28. Saito S, Tanaka S, Hiroe Y, et al. Comparative study on transradial approach vs. transfemoral approach in primary stent implantation for patients with acute myocardial infarction: results of the test for myocardial infarction by prospective unicenter randomization for access sites (TEMPURA) trial. Catheter Cardiovasc Interv 2003;59:26–33.
    Crossref | PubMed
  29. Chase AJ, Fretz EB, Warburton WP, et al. Association of the arterial access site at angioplasty with transfusion and mortality: the M.O.R.T.A.L study (Mortality benefit Of Reduced Transfusion after percutaneous coronary intervention via the Arm or Leg). Heart 2008;94:1019–25.
    Crossref | PubMed
  30. Cantor WJ, Puley G, Natarajan MK, et al. Radial versus femoral access for emergent percutaneous coronary intervention with adjunct glycoprotein IIb/IIIa inhibition in acute myocardial infarction--the RADIAL-AMI pilot randomized trial. Am Heart J 2005;150:543–9.
    Crossref | PubMed
  31. Johnman C, Pell JP, Mackay DF, et al. Clinical outcomes following radial versus femoral artery access in primary or rescue percutaneous coronary intervention in Scotland: retrospective cohort study of 4534 patients. Heart 2012;98:552–7.
    Crossref | PubMed
  32. Cox N, Resnic FS, Popma JJ, et al. Comparison of the risk of vascular complications associated with femoral and radial access coronary catheterization procedures in obese versus nonobese patients. Am J Cardiol 2004;94:1174–7.
    Crossref | PubMed
  33. Achenbach S, Ropers D, Kallert L, et al. Transradial versus transfemoral approach for coronary angiography and intervention in patients above 75 years of age. Catheter Cardiovasc Interv 2008;72:629–35.
    Crossref | PubMed
  34. Sandhu K, Nadar SK. Percutaneous coronary intervention in the elderly. Int J Cardiol 2015;199:342–55.
    Crossref | PubMed
  35. Pandie S, Mehta SR, Cantor WJ, et al. Radial versus femoral access for coronary angiography/intervention in women with acute coronary syndromes: insights from the RIVAL trial (Radial Vs femorAL access for coronary intervention). JACC Cardiovasc Interv 2015;8:505–12.
    Crossref | PubMed
  36. Mann T, Cowper PA, Peterson ED, et al. Transradial coronary stenting: comparison with femoral access closed with an arterial suture device. Catheter Cardiovasc Interv 2000;49:150–6.
    Crossref | PubMed
  37. De Carlo M, Borelli G, Gistri R, et al. Effectiveness of the transradial approach to reduce bleedings in patients undergoing urgent coronary angioplasty with GPIIb/IIIa inhibitors for acute coronary syndromes. Catheter Cardiovasc Interv 2009;74:408–15.
    Crossref | PubMed
  38. Bertrand OF, De Larochelliere R, Rodes-Cabau J, et al. A randomized study comparing same-day home discharge and abciximab bolus only to overnight hospitalization and abciximab bolus and infusion after transradial coronary stent implantation. Circulation 2006;114:2636–43.
    Crossref | PubMed
  39. Jabara R, Gadesam R, Pendyala L, et al. Ambulatory discharge after transradial coronary intervention: Preliminary US single-center experience (Same-day TransRadial Intervention and Discharge Evaluation, the STRIDE Study). Am Heart J 2008;156:1141–6.
    Crossref | PubMed
  40. Mitchell MD, Hong JA, Lee BY, et al. Systematic review and cost-benefit analysis of radial artery access for coronary angiography and intervention. Circ Cardiovasc Qual Outcomes 2012;5:454–62.
    Crossref | PubMed
  41. Cooper CJ, El-Shiekh RA, Cohen DJ, et al. Effect of transradial access on quality of life and cost of cardiac catheterization: A randomized comparison. Am Heart J 1999;138:430–6.
    Crossref | PubMed
  42. Amoroso G, Sarti M, Bellucci R, et al. Clinical and procedural predictors of nurse workload during and after invasive coronary procedures: the potential benefit of a systematic radial access. Eur J Cardiovasc Nurs 2005;4:234–41.
    Crossref | PubMed
  43. Authors/Task Force members, Windecker S, Kolh P, et al. 2014 ESC/EACTS Guidelines on myocardial revascularization: The Task Force on Myocardial Revascularization of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS)Developed with the special contribution of the European Association of Percutaneous Cardiovascular Interventions (EAPCI). Eur Heart J 2014;35:2541–619.
    Crossref | PubMed
  44. Roffi M, Patrono C, Collet JP, et al. 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation: Task Force for the Management of Acute Coronary Syndromes in Patients Presenting without Persistent ST-Segment Elevation of the European Society of Cardiology (ESC). Eur Heart J 2016;37:267–315.
    Crossref | PubMed
  45. Looi JL, Cave A, El-Jack S. Learning curve in transradial coronary angiography. Am J Cardiol 2011;108:1092–5.
    Crossref | PubMed
  46. Brueck M, Bandorski D, Kramer W, et al. A randomized comparison of transradial versus transfemoral approach for coronary angiography and angioplasty. JACC Cardiovasc Interv 2009;2:1047–54.
    Crossref | PubMed
  47. Plourde G, Pancholy SB, Nolan J, et al. Radiation exposure in relation to the arterial access site used for diagnostic coronary angiography and percutaneous coronary intervention: a systematic review and meta-analysis. Lancet 2015;386:2192–203.
    Crossref | PubMed
  48. Kasasbeh ES, Parvez B, Huang RL, et al. Learning curve in transradial cardiac catheterization: procedure-related parameters stratified by operators’ transradial volume. J Invasive Cardiol 2012;24:599–604.
    PubMed
  49. Pancholy SB, Joshi P, Shah S, et al. Effect of Vascular Access Site Choice on Radiation Exposure During Coronary Angiography: The REVERE Trial (Randomized Evaluation of Vascular Entry Site and Radiation Exposure). JACC Cardiovasc Interv 2015;8:1189–96.
    Crossref | PubMed
  50. Burzotta F, Trani C, Mazzari MA, et al. Vascular complications and access crossover in 10,676 transradial percutaneous coronary procedures. Am Heart J 2012;163:230–8.
    Crossref | PubMed
  51. Valgimigli M, Campo G, Penzo C, et al. Transradial coronary catheterization and intervention across the whole spectrum of Allen test results. J Am Coll Cardiol 2014;63:1833–41.
    Crossref | PubMed
  52. Kiemeneij F, Vajifdar BU, Eccleshall SC, et al. Measurement of radial artery spasm using an automatic pullback device. Catheter Cardiovasc Interv 2001;54:437–41.
    Crossref | PubMed
  53. Kristic I, Lukenda J. Radial artery spasm during transradial coronary procedures. J Invasive Cardiol 2011;23:527–31.
    PubMed
  54. Kwok CS, Rashid M, Fraser D, et al. Intra-arterial vasodilators to prevent radial artery spasm: a systematic review and pooled analysis of clinical studies. Cardiovasc Revasc Med 2015;16:484–90.
    Crossref | PubMed
  55. Deftereos S, Giannopoulos G, Raisakis K, et al. Moderate procedural sedation and opioid analgesia during transradial coronary interventions to prevent spasm: a prospective randomized study. JACC Cardiovasc Interv 2013;6:267–73.
    Crossref | PubMed
  56. Aminian A, Lalmand J, Dolatabadi D. Prevention of radial artery spasm: importance of a multifactorial approach. JACC Cardiovasc Interv 2013;6:1214.
    Crossref | PubMed
  57. Jolly SS, Cairns J, Niemela K, et al. Effect of radial versus femoral access on radiation dose and the importance of procedural volume: a substudy of the multicenter randomized RIVAL trial. JACC Cardiovasc Interv 2013;6:258–66.
    Crossref | PubMed
  58. Dominici M, Diletti R, Milici C, et al. Left radial versus right radial approach for coronary artery catheterization: a prospective comparison. J Interv Cardiol 2012;25:203–9.
    Crossref | PubMed
  59. Norgaz T, Gorgulu S, Dagdelen S. Arterial anatomic variations and its influence on transradial coronary procedural outcome. J Interv Cardiol 2012;25:418–24.
    Crossref | PubMed
  60. Sciahbasi A, Romagnoli E, Burzotta F, et al. Transradial approach (left vs right) and procedural times during percutaneous coronary procedures: TALENT study. Am Heart J 2011;161:172–9.
    Crossref | PubMed
  61. Guedes A, Dangoisse V, Gabriel L, et al. 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. J Invasive Cardiol 2010;22:391–7.
    Crossref | PubMed
  62. Kiemeneij F, Vajifdar BU, Eccleshall SC, et al. Evaluation of a spasmolytic cocktail to prevent radial artery spasm during coronary procedures. Catheter Cardiovasc Interv 2003;58:281–4.
    Crossref | PubMed
  63. Hizoh I, Majoros Z, Major L, et al. Need for prophylactic application of verapamil in transradial coronary procedures: a randomized trial. The VITRIOL (is Verapamil In TransRadial Interventions OmittabLe?) trial. J Am Heart Assoc 2014;3:e000588.
    Crossref | PubMed
  64. Rosencher J, Chaib A, Barbou F, et al. How to limit radial artery spasm during percutaneous coronary interventions: The spasmolytic agents to avoid spasm during transradial percutaneous coronary interventions (SPASM3) study. Catheter Cardiovasc Interv 2014;84:766–71.
    Crossref | PubMed
  65. Lo TS, Nolan J, Fountzopoulos E, et al. Radial artery anomaly and its influence on transradial coronary procedural outcome. Heart 2009;95:410–5.
    Crossref | PubMed
  66. Verouden NJ, Kiemeneij F. Balloon-assisted tracking to overcome radial spasm during transradial coronary angiography: a case report. Case Rep Cardiol 2014;2014:214310.
    Crossref | PubMed
  67. Patel T, Shah S, Pancholy S, et al. Balloon-assisted tracking: a must-know technique to overcome difficult anatomy during transradial approach. Catheter Cardiovasc Interv 2014;83:211–20.
    Crossref | PubMed
  68. Mouawad NJ, Capers Qt, Allen C, et al. Complete “in situ” avulsion of the radial artery complicating transradial coronary rotational atherectomy. Ann Vasc Surg 2015;29:123 e7–11.
    Crossref | PubMed
  69. Alkhouli M, Cohen HA, Bashir R. Radial artery avulsion--a rare complication of transradial catheterization. Catheter Cardiovasc Interv 2015;85:E32–4.
    Crossref | PubMed
  70. From AM, Gulati R, Prasad A, et al. Sheathless transradial intervention using standard guide catheters. Catheter Cardiovasc Interv 2010;76:911–6.
    Crossref | PubMed
  71. Gwon HC, Doh JH, Choi JH, et al. A 5Fr catheter approach reduces patient discomfort during transradial coronary intervention compared with a 6Fr approach: a prospective randomized study. J Interv Cardiol 2006;19:141–7.
    Crossref | PubMed
  72. Saito S, Ikei H, Hosokawa G, et al. Influence of the ratio between radial artery inner diameter and sheath outer diameter on radial artery flow after transradial coronary intervention. Catheter Cardiovasc Interv 1999;46:173–8.
    Crossref | PubMed
  73. Rathore S, Stables RH, Pauriah M, et al. Impact of length and hydrophilic coating of the introducer sheath on radial artery spasm during transradial coronary intervention: a randomized study. JACC Cardiovasc Interv 2010;3:475–83.
    Crossref | PubMed
  74. Kiemeneij F, Fraser D, Slagboom T, et al. Hydrophilic coating aids radial sheath withdrawal and reduces patient discomfort following transradial coronary intervention: a randomized double-blind comparison of coated and uncoated sheaths. Catheter Cardiovasc Interv 2003;59:161–4.
    Crossref | PubMed
  75. Aminian A, Dolatabadi D, Lefebvre P, et al. Initial experience with the Glidesheath Slender for transradial coronary angiography and intervention: a feasibility study with prospective radial ultrasound follow-up. Catheter Cardiovasc Interv 2014;84:436–42.
    Crossref | PubMed
  76. Yoshimachi F, Kiemeneij F, Masutani M, et al. Safety and feasibility of the new 5 Fr Glidesheath Slender. Cardiovasc Interv Ther 2016;31 :38–41.
    Crossref | PubMed
  77. Miyasaka M, Tada N, Kato S, et al. Sheathless guide catheter in transradial percutaneous coronary intervention for ST-segment elevation myocardial infarction. Catheter Cardiovasc Interv 2016;87:1111–7.
    Crossref | PubMed
  78. Li Q, He Y, Jiang R, et al. Using sheathless standard guiding catheters for transradial percutaneous coronary intervention to treat bifurcation lesions. Exp Clin Cardiol 2013;18:73–6.
    PubMed
  79. Pancholy S, Coppola J, Patel T, et al. Prevention of radial artery occlusion-patent hemostasis evaluation trial (PROPHET study): a randomized comparison of traditional versus patency documented hemostasis after transradial catheterization. Catheter Cardiovasc Interv 2008;72:335–40.
    Crossref | PubMed
  80. Cubero JM, Lombardo J, Pedrosa C, et al. Radial compression guided by mean artery pressure versus standard compression with a pneumatic device (RACOMAP). Catheter Cardiovasc Interv 2009;73:467–72.
    Crossref | PubMed
  81. Spaulding C, Lefevre T, Funck F, et al. Left radial approach for coronary angiography: results of a prospective study. Cathet Cardiovasc Diagn 1996;39:365–70.
    Crossref | PubMed
  82. Pancholy SB. Comparison of the effect of intra-arterial versus intravenous heparin on radial artery occlusion after transradial catheterization. Am J Cardiol 2009;104:1083–5.
    Crossref | PubMed