Following the initial studies of radial access in coronary angiography, the cardiology literature has experienced significant growth in contemporary evidence suggesting that radial access is associated with more favorable outcomes compared to femoral access in coronary intervention.1-20 Percutaneous coronary intervention (PCI) procedures undertaken through the transradial approach are associated with significant reductions in mortality, major bleeding, and major vascular access site complications in high-risk patient groups.1-20 They have also been shown to be cost effective21-23 and associated with better quality of life for the patient.24 The benefits of a radial access strategy are particularly evident in individuals at high risk for bleeding complications,25 elderly patients,1 STEMI patients,1,7,26 those with acute coronary syndromes,4,26,27 women,17,28-31 and hemodynamically unstable patients18 (particularly those in cardiogenic shock).16,18,32 Nevertheless, radial access can be technically challenging in these individuals, the learning curve can take longer to master,33-36 and uptake has not been universal.

THE DATA AND THE DEBATE

Recently, the influence of center and operator volume in interventional cardiology has been a matter of debate and controversy.37-42 Some studies have suggested that low operator/institutional volume may be related to increased rates of adverse events.43-45 These data have led the Society for Cardiovascular Angiography and Interventions46 and the British Cardiovascular Interventional Society to issue guidelines47 advocating a minimum prerequisite of 50 and 150 procedures, respectively, over 2 years to maintain proficiency to perform PCI. A meta-analysis48 of approximately 16,000 operators who had performed more than 200,000 PCIs suggested that the incidence of major adverse cardiac events (MACE) was inversely related to operator volume, with an odds ratio (OR) of 0.62 (95% CI [confidence interval], 0.4–0.97).

Badheka et al40 performed the largest analysis, which encompassed 457,498 PCIs. The operator volumes were classified into four quartiles: the first quartile had performed ≤ 15 PCIs per year, the second had 16 to 44 PCIs per year, the third had 45 to 100 PCIs per year, and the fourth had > 100 PCIs per year. After adjusting for covariates, it was observed that improved in-hospital mortality outcomes were associated with high operator volumes: the second quartile had an OR of 0.8 (0.74–0.87; P < .001), the third quartile’s OR was 0.81 (0.74–0.89; P < .001), and the fourth quartile’s OR was 0.65 (0.58–0.73; P < .001) compared to the first quartile. A further meta-analysis49 comprising more than a million individuals that compared outcomes in patients undergoing PCI at high- and low-volume centers suggested a mortality benefit with an OR of 0.87 (95% CI, 0.83–0.91) for patients treated at high-volume centers.

However, the evidence thus far has various limitations because there were different definitions of high- and low-volume operators, accounting for significant heterogeneity.37,50,51 For instance, Vakili et al51 compared outcomes in ≥ 11 versus one to two procedures per year, whereas Madan et al52 compared ≥ 100 with < 100 procedures per year. In addition, many studies did not adjust for various confounding factors,44,53 and most often, operator volume was a categorical variable rather than a continuous variable.40 Because of these highlighted issues, the evidence should be interpreted with caution.

The operator/institutional volume appears to be more important in primary percutaneous coronary intervention (PPCI) outcomes.51,53,54 Studies from New York51,54 showed a significant reduced mortality risk associated with high-volume operators (defined as ≥ 10 PPCIs/y54 and ≥ 11 PPCIs/y).51 Similarly, Srinivas et al54 observed a reduced risk of mortality in high-volume hospitals (≥ 50 PPCIs/y), with an OR of 0.58 (95% CI, 0.39–0.86). However, this benefit was not observed in low-volume hospitals (< 50 PPCIs/y), with an OR of 1.44 (95% CI, 0.68–3.03). On the other hand, Politi et al53 suggested that there was no relationship between PPCI outcomes and operator volume.

Similarly, recent studies have suggested a relationship between center and operator volume and clinical outcomes associated with radial access site practice. A large study55 from the Veterans Affairs health care system in North America between 2007 and 2010 reported outcomes from 24,143 patients. In this study, a high-volume center was defined as one that performs more than 50 radial PCIs per year. In a propensity-matched analysis, a reduced incidence of blood transfusion after PCI was demonstrated among the high-volume centers (hazard ratio [HR], 0.4; 95% CI, 0.3–0.7); however, no survival benefit was established. Similarly, a multicenter study of 10,000 patients with non–ST-segment elevation myocardial infarction56 confirmed a mortality benefit at 1 year with radial access (compared to femoral access) in high-volume institutions with an HR of 0.7 (95% CI, 0.51–0.97), whereas no mortality benefit was observed among the low-volume institutions (HR, 0.8; 95% CI, 0.47–1.38).

The RIVAL trial26,57-59 is a randomized, controlled, multicenter trial of 7,021 patients with acute coronary syndromes who were randomized to radial versus femoral access for PCI. Although the composite endpoint of death, myocardial infarction (MI), stroke, or major bleeding unrelated to coronary artery bypass grafting was similar in the radial and femoral arms (HR, 0.92; 95% CI, 0.72–1.17), a subgroup analysis suggested superior outcomes in high-volume radial centers. The centers in the trial were classified into low (≤ 60 radial PCIs/y per operator), intermediate (61–146 radial PCIs/y per operator), and high-volume (> 146 radial PCIs/y per operator).58 Operator volume was classified into low (≤ 70 radial PCIs/y per operator), intermediate (71–142 radial PCIs/y per operator), and high (> 142 radial PCIs/y per operator).58 Transradial access at high-volume radial centers was associated with a significant reduction in the primary endpoint compared to femoral access (HR, 0.49; 95% CI, 0.28–0.87). However, the statistically significant reduction in the primary endpoint in the radial access arm was not observed in the intermediate- or low-volume centers, and there was no link between individual operator radial volume and the primary endpoint.58

The MATRIX trial27 included 8,404 patients with acute coronary syndromes and is the largest trial to date comparing radial and femoral access in this context. The investigators classified contributing institutions’ percentages of radial PCIs as low (14.9%–64.4%), intermediate (65.4%–79%), and high (80%–98%). Both MACE and net clinical adverse events (NACE) associated with radial access were significantly lower (compared to femoral access) in the high-volume radial centers, with HRs of 0.64. The improved MACE and NACE outcomes associated with radial access were not observed in low-volume radial centers, with HRs for MACE and NACE of 1.04 (95% CI, 0.79–1.36) and 1.01 (95% CI, 0.79–1.29), respectively. However, some have suggested that this could merely be a reflection of higher femoral events in the high-volume radial centers because of heterogeneity in access site expertise, leading to possible bias.60-62 This is unlikely because the worst crude femoral outcomes observed in the high-proportion radial centers were also accompanied by greater crude event rates in the radial arms, suggesting that the case mix in these centers was more complex. The authors of the MATRIX trial discarded this hypothesis by demonstrating that there was no heterogeneity in their meta-analysis, which included the RIVAL and MATRIX trials.63

The literature16,55,56,58,64 prior to the MATRIX trial27 only reflected outcomes with respect to radial total volumes and neglected the proportion of procedures done radially, which is an important variable. Table 1 illustrates the key studies assessing the relationship between radial volume and clinical outcomes. Much of the previous literature that has reported volume outcome relationships with transradial access is derived from North American centers where ≥ 50 radial procedures per year yields a definition as a high-volume radial center.26 In many European countries, this volume of radial procedures would be considered extremely low.

Radial volume at both the operator and institutional level are not a true reflection of radial proficiency. Low-proportion radial operators/institutions with high total procedural volumes (radial + femoral) would have been considered high-volume radial operators/centers in the earlier studies.16,55,56,58,64 High-proportion radial operators are more likely to be experienced and proficient in the transradial approach and would be more likely to utilize this approach in high-risk individuals who have the most to benefit from a radial approach.25

The British Cardiovascular Intervention Society (BCIS) registry18 was the largest study to systematically evaluate operator radial proportion and its relationship with outcomes. This analysis of 164,395 PCIs strongly supports the use of a radial approach, with a 39% decrease in mortality (OR, 0.61; 95% CI, 0.55–0.68). The magnitude of this benefit is further amplified with increases in radial proportion and total procedural volume at the operator level. Reductions in the risk of 30-day mortality by 11% per 100 additional procedures (95% CI, 3%–19%) and a 6% per 10 percentage point increase in radial proportion (95% CI, 1%–11%) was reported in this large-scale analysis. Interestingly, once other measures of experience were adjusted for, operator radial volume, center total volume, center radial volume, and center radial proportion were not independently associated with improved 30-day mortality outcomes. The authors performed a sensitivity analysis after excluding patients with cardiogenic shock from the analysis and found that the mortality benefit with high-proportion radial operators was maintained.

The mechanisms that explain the magnitude of the mortality benefit observed with high-proportion radial operators are likely to be increasing proficiency and the utilization of this procedure in critically ill individuals who are at highest risk for bleeding complications and therefore have the most to benefit from transradial access.25 Initially, during the learning phase of radial procedures, low-proportion radial operators are more likely to utilize radial access in elective, stable cases with a lower bleeding risk in which the benefit of transradial access is less.

SUMMARY

The transradial approach has gained popularity, and as a result, a 13-fold increase in adoption of radial angioplasty has been observed across the United States.65 In most European centers, radial access has become the default approach and the new gold standard. This practice is strongly supported by the European Society of Cardiology guidelines,20 which provided a level IA recommendation for the transradial approach in managing patients with acute coronary syndromes soon after the publication of the MATRIX trial.27 The BCIS registry data add robust evidence to the existing literature by providing key insights regarding the complex relationship between volume and access site–related outcomes.18 The results from this large cohort demonstrate that further significant survival benefit can be achieved in the hands of high-proportion radial operators and that the ­mortality benefit achieved by the transradial approach is not related to total volume or radial volume at the center level after adjusting for confounding factors. Currently, the European Association of Percutaneous Cardiovascular Intervention66 recommends performing > 50% of all diagnostic angiography and angioplasty procedures radially, with a minimum of 80 procedures/annum per operator.

The future of coronary intervention via radial access is bright, and the results of the BCIS registry have implications for interventional cardiologists and cardiac catheterization labs globally. Some suggest that the transradial approach could be the next quality metric67 and would set new standards for the proportion of angioplasties performed via the radial artery.

1. Cantor WJ, Mehta SR, Yuan F, et al. Radial versus femoral access for elderly patients with acute coronary syndrome undergoing coronary angiography and intervention: insights from the RIVAL trial. Am Heart J. 2015;170:880-886.

2. Vorobcsuk A, Konyi A, Aradi D, et al. Transradial versus transfemoral percutaneous coronary intervention in acute myocardial infarction: systematic overview and meta-analysis. Am Heart J. 2009;158:814-821.

3. Singh PP, Singh M, Khosla N, et al. Safety and efficacy of transradial versus transfemoral percutaneous coronary intervention in acute myocardial infarction: a meta-analysis of randomized trials. Coron Artery Dis. 2012;23:284-293.

4. Piccolo R, Galasso G, Capuano E, et al. Transradial versus transfemoral approach in patients undergoing percutaneous coronary intervention for acute coronary syndrome: a meta-analysis and trial sequential analysis of randomized controlled trials. PLoS One. 2014;9:e96127.

5. Patel VG, Brayton KM, Kumbhani DJ, et al. Meta-analysis of stroke after transradial versus transfemoral artery catheterization. Int J Cardiol. 2013;168:5234-5238.

6. Mamas MA, Ratib K, Routledge H, et al. Influence of access site selection on PCI-related adverse events in patients with STEMI: meta-analysis of randomised controlled trials. Heart. 2012;98:303-311.

7. 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;6:814-823.

8. Joyal D, Bertrand OF, Rinfret S, et al. Meta-analysis of ten trials on the effectiveness of the radial versus the femoral approach in primary percutaneous coronary intervention. Am J Cardiol. 2012;109:813-818.

9. 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;157:132-140.

10. Jang JS, Jin HY, Seo JS, et al. The transradial versus the transfemoral approach for primary percutaneous coronary intervention in patients with acute myocardial infarction: a systematic review and meta-analysis. EuroIntervention. 2012;8:501-510.

11. He P, Yang Y, Hu F. Transradial versus transfemoral percutaneous coronary intervention in elderly patients: a systematic overview and meta-analysis. Chin Med J. 2014;127:1110-1117.

12. Ando G, Capodanno D. Radial versus femoral access in invasively managed patients with acute coronary syndrome: a systematic review and meta-analysis. Ann Intern Med. 2015;163:932-940.

13. Mamas MA, Ratib K, Routledge H, et al. Influence of arterial access site selection on outcomes in primary percutaneous coronary intervention: are the results of randomized trials achievable in clinical practice? JACC Cardiovasc Interv. 2013;6:698-706.

14. Mamas MA, Nolan J, de Belder MA, et al. Changes in arterial access site and association with mortality in the United Kingdom: observations from a national percutaneous coronary intervention database. Circulation. 2016;133:1655-1667.

15. Mamas MA, Fraser DG, Ratib K, et al. Minimising radial injury: prevention is better than cure. EuroIntervention. 2014;10:824-832.

16. Mamas MA, Anderson SG, Ratib K, et al. Arterial access site utilization in cardiogenic shock in the United Kingdom: is radial access feasible? Am Heart J. 2014;167:900-8.e1.

17. Kwok CS, Kontopantelis E, Kunadian V, et al. Effect of access site, gender, and indication on clinical outcomes after percutaneous coronary intervention: insights from the British Cardiovascular Intervention Society (BCIS). Am Heart J. 2015;170:164-172.

18. Hulme W, Sperrin M, Rushton H, et al. Is there a relationship of operator and center volume with access site-related outcomes? An analysis from the British Cardiovascular Intervention Society. Circ Cardiovasc Interv. 2016;9:e003333.

19. Anderson SG, Ratib K, Myint PK, et al. Impact of age on access site-related outcomes in 469,983 percutaneous coronary intervention procedures: insights from the British Cardiovascular Intervention Society. Catheter Cardiovasc Interv. 2015;86:965-972.

20. Roffi M, Patrono C, Collet J-P, 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.

21. Safley DM, Amin AP, House JA, et al. Comparison of costs between transradial and transfemoral percutaneous coronary intervention: a cohort analysis from the Premier research database. Am Heart J. 2013;165:303-309.

22. Jin C, Li W, Qiao SB, et al. Costs and benefits associated with transradial versus transfemoral percutaneous coronary intervention in China. J Am Heart Assoc. 2016;5:e002684.

23. Amin AP, House JA, Safley DM, et al. Costs of transradial percutaneous coronary intervention. JACC Cardiovasc Interv. 2013;6:827-834.

24. Koltowski L, Koltowska-Haggstrom M, Filipiak KJ, et al. Quality of life in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention—radial versus femoral access (from the OCEAN RACE trial). Am J Cardiol. 2014;114:516-521.

25. Mamas MA, Anderson SG, Carr M, et al. Baseline bleeding risk and arterial access site practice in relation to procedural outcomes after percutaneous coronary intervention. J Am Coll Cardiol. 2014;64:1554-1564.

26. 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;377:1409-1420.

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;385:2465-2476.

28. Tizon-Marcos H, Bertrand OF, Rodes-Cabau J, et al. Impact of female gender and transradial coronary stenting with maximal antiplatelet therapy on bleeding and ischemic outcomes. Am Heart J. 2009;157:740-745.

29. Jibran R, Khan JA, Hoye A. Gender disparity in patients undergoing percutaneous coronary intervention for acute coronary syndromes—does it still exist in contemporary practice? Ann Acad Med Singapore. 2010;39:173-178.

30. Huang FY, Huang BT, Wang PJ, et al. Gender disparity in the safety and efficacy of radial and femoral access for coronary intervention: a systematic review and meta-analysis [published online ahead of print December 13, 2015]. Angiology.

31. 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;8:505-512.

32. Gandhi S, Kakar R, Overgaard CB. Comparison of radial to femoral PCI in acute myocardial infarction and cardiogenic shock: a systematic review. J Thromb Thrombolysis. 2015;40:108-117.

33. Hess CN, Peterson ED, Neely ML, et al. Response to letter regarding article, “The learning curve for transradial percutaneous coronary intervention among operators in the United States: a study from the National Cardiovascular Data Registry.” Circulation. 2015;131:e358.

34. Hess CN, Peterson ED, Neely ML, et al. The learning curve for transradial percutaneous coronary intervention among operators in the United States: a study from the National Cardiovascular Data Registry. Circulation. 2014;129:2277-2286.

35. Ball WT, Sharieff W, Jolly SS, et al. Characterization of operator learning curve for transradial coronary interventions. Circ Cardiovasc Interv. 2011;4:336-341.

36. Barbash IM, Minha S, Gallino R, et al. Operator learning curve for transradial percutaneous coronary interventions: implications for the initiation of a transradial access program in contemporary US practice. Cardiovasc Revasc Med. 2014;15:195-199.

37. Rashid M, Sperrin M, Ludman PF, et al. Impact of operator volume for percutaneous coronary intervention on clinical outcomes: what do the numbers say? Eur Heart J Qual Care Clin Outcomes. 2016;2:16-22.

38. Badheka AO, Panaich SS, Arora S, et al. Percutaneous coronary intervention: relationship between procedural volume and outcomes. Curr Cardiol Rep. 2016;18:39.

39. Badheka AO, Patel NJ, Grover P, et al. Response to letter regarding article “Impact of annual operator and institutional volume on percutaneous coronary intervention outcomes: a 5-year United States experience (2005-2009).” Circulation. 2015;132:e36-37.

40. Badheka AO, Patel NJ, Grover P, et al. Impact of annual operator and institutional volume on percutaneous coronary intervention outcomes: a 5-year United States experience (2005-2009). Circulation. 2014;130:1392-1406.

41. Khera R, Cram P, Girotra S. Letter by Khera et al regarding article, “Impact of annual operator and institutional volume on percutaneous coronary intervention outcomes: a 5-year United States experience (2005-2009).” Circulation 2015;132:e35.

42. Badheka AO, Patel NJ, Panaich SS, et al. Effect of hospital volume on outcomes of transcatheter aortic valve implantation. Am J Cardiol. 2015;116:587-594.

43. Jollis JG, Peterson ED, DeLong ER, et al. The relation between the volume of coronary angioplasty procedures at hospitals treating Medicare beneficiaries and short-term mortality. N Engl J Med. 1994;331:1625-1629.

44. Hannan EL, Racz M, Ryan TJ, et al. Coronary angioplasty volume-outcome relationships for hospitals and cardiologists. JAMA. 1997;277:892-898.

45. McGrath PD, Wennberg DE, Malenka DJ, et al. Operator volume and outcomes in 12,998 percutaneous coronary interventions. Northern New England Cardiovascular Disease Study Group. J Am Coll Cardiol. 1998;31:570-576.

46. Harold JG, Bass TA, Bashore TM, et al. ACCF/AHA/SCAI 2013 Update of the Clinical Competence Statement on Coronary Artery Interventional Procedures: a Report of the American College of Cardiology Foundation/American Heart Association/American College of Physicians Task Force on Clinical Competence and Training (Writing Committee to Revise the 2007 Clinical Competence Statement on Cardiac Interventional Procedures). Catheter Cardiovasc Interv. 2013;82:E69-111.

47. Banning AP, Baumbach A, Blackman D, et al. Percutaneous coronary intervention in the UK: recommendations for good practice 2015. Heart. 2015;101:1-13.

48. Strom JB, Wimmer NJ, Wasfy JH, et al. Association between operator procedure volume and patient outcomes in percutaneous coronary intervention: a systematic review and meta-analysis. Circ Cardiovasc Qual Outcomes. 2014;7:560-566.

49. Post PN, Kuijpers M, Ebels T, Zijlstra F. The relation between volume and outcome of coronary interventions: a systematic review and meta-analysis. Eur Heart J. 2010;31:1985-1992.

50. Shook TL, Sun GW, Burstein S, et al. Comparison of percutaneous transluminal coronary angioplasty outcome and hospital costs for low-volume and high-volume operators. Am J Cardiol. 1996;77:331-336.

51. Vakili BA, Kaplan R, Brown DL. Volume-outcome relation for physicians and hospitals performing angioplasty for acute myocardial infarction in New York state. Circulation. 2001;104:2171-2176.

52. Madan M, Nikhil J, Hellkamp AS, et al. Effect of operator and institutional volume on clinical outcomes after percutaneous coronary interventions performed in Canada and the United States: a brief report from the Enhanced Suppression of the Platelet Glycoprotein IIb/IIIa Receptor With Integrilin Therapy (ESPRIT) study. Can J Cardiol. 2009;25:e269-272.

53. Politi A, Galli M, Zerboni S, et al. Operator volume and outcomes of primary angioplasty for acute myocardial infarction in a single high-volume centre. J Cardiovasc Med (Hagerstown). 2006;7:761-767.

54. Srinivas VS, Hailpern SM, Koss E, et al. Effect of physician volume on the relationship between hospital volume and mortality during primary angioplasty. J Am Coll Cardiol. 2009;53:574-579.

55. Gutierrez A, Tsai TT, Stanislawski MA, et al. Adoption of transradial percutaneous coronary intervention and outcomes according to center radial volume in the Veterans Affairs Healthcare system: insights from the Veterans Affairs clinical assessment, reporting, and tracking (CART) program. Circ Cardiovasc Interv. 2013;6:336-346.

56. Iqbal MB, Arujuna A, Ilsley C, et al. Radial versus femoral access is associated with reduced complications and mortality in patients with non-ST-segment-elevation myocardial infarction: an observational cohort study of 10,095 patients. Circ Cardiovasc Interv. 2014;7:456-464.

57. Jolly SS, Niemela K, Xavier D, et al. Design and rationale of the radial versus femoral access for coronary intervention (RIVAL) trial: a randomized comparison of radial versus femoral access for coronary angiography or intervention in patients with acute coronary syndromes. Am Heart J. 2011;161:254-260.

58. Jolly SS, Cairns J, Yusuf S, et al. Procedural volume and outcomes with radial or femoral access for coronary angiography and intervention. J Am Coll Cardiol. 2014;63:954-963.

59. 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;60:2490-2499.

60. Dowling C, Rao S, Kerr N, Muller D. Radial versus femoral access for cardiac catheterisation. Lancet. 2015;386:2392.

61. Brieger D, Yong A. Radial versus femoral access for cardiac catheterisation. Lancet. 2015;386:2393-2394.

62. Shah R, Gardner JD. Radial versus femoral access for cardiac catheterisation. Lancet. 2015;386:2392-2393.

63. Valgimigli M, Gargiulo G, Juni P. Radial versus femoral access for cardiac catheterisation–authors’ reply. Lancet. 2015;386:2394.

64. 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;6:258-266.

65. 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;127:2295-2306.

66. Hamon M, Pristipino C, Di Mario C, et al. Consensus document on the radial approach in percutaneous cardiovascular interventions: position paper by the European Association of Percutaneous Cardiovascular Interventions and Working Groups on Acute Cardiac Care and Thrombosis of the European Society of Cardiology. EuroIntervention. 2013;8:1242-1251.

67. Cavender MA, Kaul P. Is it time for radial access to become a quality metric for percutaneous coronary intervention? Circ Cardiovasc Interv. 2016;9:e003881.

Vinayak Nagaraja, MBBS, MS
Department of Cardiology
Prince of Wales Hospital
Sydney, New South Wales, Australia
Disclosures: None.

Jim Nolan, MBChB, MD, FRCP
Royal Stoke University Hospital
University Hospitals of North Midlands
Keele Cardiovascular Research Group
Institute of Science and Technology in Medicine
University of Keele, Stoke-on-Trent, United Kingdom
Disclosures: None.

Mamas A. Mamas, BM BCh, MA, DPhil, MRCP
Royal Stoke University Hospital
University Hospitals of North Midlands
Keele Cardiovascular Research Group
Institute of Science and Technology in Medicine
University of Keele, Stoke-on-Trent, United Kingdom
mamasmamas1@yahoo.co.uk
Disclosures: None.