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Cardiac catheterisation: radiation for radialists
Comment
Cardiac catheterisation: radiation for radialists product, was non-significantly higher for the radial access site with coronary angiography (1·72 Gy·cm² [95% CI –0·10 to 3·55]; p=0·06), and significantly higher with PCI (0·55 Gy·cm²; [0·08–1·02]; p=0·02). These results were similar for observational studies included in the analysis. Although Plourde and colleagues’ study7 provides important information on increased fluoroscopy times and patients’ radiation exposure for the radial access site, it does not give a definite answer on whether actual radiation exposure is higher for the interventionalists. Only four studies included in the meta-analysis assessed radiation exposure according to badge dosimeters of the operators. Although a linear relation exists between operator exposure and patient exposure irrespective of the number of radial or femoral procedures done by individual operators,8 a randomised controlled trial comparing radial and femoral access sites while assessing interventionalist radiation exposure using badge dosimeters is necessary to draw final conclusions on this issue. The results of one such trial—the Randomized Evaluation of Vascular Entry site and Radiation Exposure (REVERE) trial have been published.9 In this trial with 1493 patients, left radial, right radial, and femoral access sites are compared with primary radiation exposure endpoints, including operator radiation exposure assessed by a personal dosimeter worn outside the lead apron on the vest pocket. Radiation exposure was similar during diagnostic coronary angiography in all groups.
www.thelancet.com Published online September 25, 2015 http://dx.doi.org/10.1016/S0140-6736(15)00306-2
Published Online September 25, 2015 http://dx.doi.org/10.1016/ S0140-6736(15)00306-2 See Online/Articles http://dx.doi.org/10.1016/ S0140-6736(15)00305-0
Ria Novosti/Science Photo Library
Since the introduction of radial artery access for cardiac catheterisation in the early 1990s by Campeau and Kiemeneij,1,2 more than 20 years have passed before it has been acknowledged as the preferred technique for coronary angiograms and percutaneous coronary intervention (PCI). A published trial and subsequent meta-analysis of all randomised trials published since the RadIal Versus femorAL (RIVAL) study3 comparing radial artery with femoral artery access site in patients with acute coronary syndromes showed that the radial artery route resulted in a reduction in major bleeding and all-cause mortality.4 Moreover, patients’ comfort is also higher with the radial approach.5 For these reasons, many interventionalists are nowadays more familiar and comfortable with the radial access site, whereas the femoral route is often restricted to patients with contraindications to use of the radial artery or during bailout situations. This is true not only in Europe and Japan, but also in the USA where use of radial access is rapidly growing.6 However, concerns exist with regard to the radiation exposure for the interventionalists in view of the growing number of radial procedures. During interventional procedures done via the radial route, the operator is in closer vicinity to the x-ray source than with the femoral route, which hypothetically could result in a higher intensity of scattered radiation. Procedural times might also be longer, especially when operators have little experience with radial access. Additionally, the complexity of procedures done via the radial route is increasing. Therefore, radiation exposure is an important safety issue for interventionalists and nursing staff who often spend decades of their careers in a cardiac catheterisation laboratory. In The Lancet, Guillaume Plourde and colleagues7 report a thorough and robust meta-analysis of all available radiation data from 24 randomised controlled trials for 19 328 patients who underwent coronary angiograms or PCI, stratified by the two different access-site routes. The investigators conclude that radial access site is associated with a small but significant increase in fluoroscopy time during both coronary angiography (weighted mean difference fixed effect 1·04 min [95% CI 0·84–1·24]) and PCI (1·15 min [0·96–1·33]). Radiation exposure, as measured by kerma-area
1
Comment
However, the left radial artery access site was associated with significantly higher operator radiation exposure compared with the femoral and right radial artery access site.9 These results have to be confirmed in larger trials. In the meantime, should we reconsider access site options and move away from the radial access route? Although we should not put aside Plourde and colleagues’ data7 showing that radiation exposure slightly increases with the radial route, several arguments indicate that the clock should not be turned back. From a stochastic point of view, the annual or even lifelong exposure rather than the exposure per procedure is most relevant for a health worker’s safety. These annual doses can be reduced by several precautions, such as lowering the equipment’s pulse rate during fluoroscopy or decreasing the cine time. From a patient’s perspective, the small increase in radiation exposure will probably not outweigh the benefits of radial access. Moreover, Plourde and colleagues also show that differences in radiation exposure diminished over time (eg, the overall difference in fluoroscopy time between radial and femoral access has reduced by 75% during the past 20 years, from 2 min in 1996 to about 30 s in 2014). This finding shows that, with increasing experience of the radial versus femoral access site, differences in radiation exposure are vanishing. We can only speculate on how this difference in radiation exposure will affect cardiac catheterisation procedures 20 years from now, when the fellows-intraining of today (with little experience of the femoral access site) will be leaders of the catheterisation laboratories of tomorrow. In the meantime, awareness of radiation exposure during diagnostic or interventional procedures is of utmost importance. The radiation exposure is highly variable per operator, even when corrected for the complexity of the procedure.10
2
Moreover, with each study that assesses radiation exposure, the actual exposure decreases because of the increasing awareness of radiation. It is important that this awareness is conveyed to future interventionalists and nursing staff to improve safety for both patients and health workers during such procedures. *Ronak Delewi, Jan J Piek Heart Center, Academic Medical Center–University of Amsterdam, 1105 AZ Amsterdam, Netherlands [email protected] RD has received research funding from AstraZeneca, Svelte Medical, Osprey Medical, and Guerbet. JJP has received grants and personal fees from Miracor and Abbott Vascular. 1
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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. Campeau L. Percutaneous radial artery approach for coronary angiography. Cathet Cardiovasc Diagn 1989; 16: 3–7. Jolly SS, Yusuf S, Cairns J, et al, for the RIVAL trial group. 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. Valgimigli M, Gagnor A, Calabró P, et al, for the MATRIX Investigators. Radial versus femoral access in patients with acute coronary syndromes undergoing invasive management: a randomised multicentre trial. Lancet 2015; 385: 2465–76. 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: 430–36. Feldman DN, Swaminathan RV, Kaltenbach LA, et al. Adoption of radial access and comparison of outcomes to femoral access in percutaneous coronary intervention. Circulation 2013; 127: 2295–306. 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; published online Sept 25. http://dx.doi.org/10.1016/S01406736(15)00305-0. Kuipers G, Delewi R, Velders XL, et al. Exposure of cardiologists from interventional procedures. Radiat Prot Dosimetry 2010; 140: 259–65. Pancholy SB, Joshi P, Shah S, Rao SV, Bertrand OF, Patel TM. 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; 9: 1189–96. Delewi R, Hoebers LP, Råmunddal T, et al. Clinical and procedural characteristics associated with higher radiation exposure during percutaneous coronary interventions and coronary angiography. Circ Cardiovasc Interv 2013; 5: 501–06.
www.thelancet.com Published online September 25, 2015 http://dx.doi.org/10.1016/S0140-6736(15)00306-2
Cardiac catheterisation: radiation for radialists product, was non-significantly higher for the radial access site with coronary angiography (1·72 Gy·cm² [95% CI –0·10 to 3·55]; p=0·06), and significantly higher with PCI (0·55 Gy·cm²; [0·08–1·02]; p=0·02). These results were similar for observational studies included in the analysis. Although Plourde and colleagues’ study7 provides important information on increased fluoroscopy times and patients’ radiation exposure for the radial access site, it does not give a definite answer on whether actual radiation exposure is higher for the interventionalists. Only four studies included in the meta-analysis assessed radiation exposure according to badge dosimeters of the operators. Although a linear relation exists between operator exposure and patient exposure irrespective of the number of radial or femoral procedures done by individual operators,8 a randomised controlled trial comparing radial and femoral access sites while assessing interventionalist radiation exposure using badge dosimeters is necessary to draw final conclusions on this issue. The results of one such trial—the Randomized Evaluation of Vascular Entry site and Radiation Exposure (REVERE) trial have been published.9 In this trial with 1493 patients, left radial, right radial, and femoral access sites are compared with primary radiation exposure endpoints, including operator radiation exposure assessed by a personal dosimeter worn outside the lead apron on the vest pocket. Radiation exposure was similar during diagnostic coronary angiography in all groups.
www.thelancet.com Published online September 25, 2015 http://dx.doi.org/10.1016/S0140-6736(15)00306-2
Published Online September 25, 2015 http://dx.doi.org/10.1016/ S0140-6736(15)00306-2 See Online/Articles http://dx.doi.org/10.1016/ S0140-6736(15)00305-0
Ria Novosti/Science Photo Library
Since the introduction of radial artery access for cardiac catheterisation in the early 1990s by Campeau and Kiemeneij,1,2 more than 20 years have passed before it has been acknowledged as the preferred technique for coronary angiograms and percutaneous coronary intervention (PCI). A published trial and subsequent meta-analysis of all randomised trials published since the RadIal Versus femorAL (RIVAL) study3 comparing radial artery with femoral artery access site in patients with acute coronary syndromes showed that the radial artery route resulted in a reduction in major bleeding and all-cause mortality.4 Moreover, patients’ comfort is also higher with the radial approach.5 For these reasons, many interventionalists are nowadays more familiar and comfortable with the radial access site, whereas the femoral route is often restricted to patients with contraindications to use of the radial artery or during bailout situations. This is true not only in Europe and Japan, but also in the USA where use of radial access is rapidly growing.6 However, concerns exist with regard to the radiation exposure for the interventionalists in view of the growing number of radial procedures. During interventional procedures done via the radial route, the operator is in closer vicinity to the x-ray source than with the femoral route, which hypothetically could result in a higher intensity of scattered radiation. Procedural times might also be longer, especially when operators have little experience with radial access. Additionally, the complexity of procedures done via the radial route is increasing. Therefore, radiation exposure is an important safety issue for interventionalists and nursing staff who often spend decades of their careers in a cardiac catheterisation laboratory. In The Lancet, Guillaume Plourde and colleagues7 report a thorough and robust meta-analysis of all available radiation data from 24 randomised controlled trials for 19 328 patients who underwent coronary angiograms or PCI, stratified by the two different access-site routes. The investigators conclude that radial access site is associated with a small but significant increase in fluoroscopy time during both coronary angiography (weighted mean difference fixed effect 1·04 min [95% CI 0·84–1·24]) and PCI (1·15 min [0·96–1·33]). Radiation exposure, as measured by kerma-area
1
Comment
However, the left radial artery access site was associated with significantly higher operator radiation exposure compared with the femoral and right radial artery access site.9 These results have to be confirmed in larger trials. In the meantime, should we reconsider access site options and move away from the radial access route? Although we should not put aside Plourde and colleagues’ data7 showing that radiation exposure slightly increases with the radial route, several arguments indicate that the clock should not be turned back. From a stochastic point of view, the annual or even lifelong exposure rather than the exposure per procedure is most relevant for a health worker’s safety. These annual doses can be reduced by several precautions, such as lowering the equipment’s pulse rate during fluoroscopy or decreasing the cine time. From a patient’s perspective, the small increase in radiation exposure will probably not outweigh the benefits of radial access. Moreover, Plourde and colleagues also show that differences in radiation exposure diminished over time (eg, the overall difference in fluoroscopy time between radial and femoral access has reduced by 75% during the past 20 years, from 2 min in 1996 to about 30 s in 2014). This finding shows that, with increasing experience of the radial versus femoral access site, differences in radiation exposure are vanishing. We can only speculate on how this difference in radiation exposure will affect cardiac catheterisation procedures 20 years from now, when the fellows-intraining of today (with little experience of the femoral access site) will be leaders of the catheterisation laboratories of tomorrow. In the meantime, awareness of radiation exposure during diagnostic or interventional procedures is of utmost importance. The radiation exposure is highly variable per operator, even when corrected for the complexity of the procedure.10
2
Moreover, with each study that assesses radiation exposure, the actual exposure decreases because of the increasing awareness of radiation. It is important that this awareness is conveyed to future interventionalists and nursing staff to improve safety for both patients and health workers during such procedures. *Ronak Delewi, Jan J Piek Heart Center, Academic Medical Center–University of Amsterdam, 1105 AZ Amsterdam, Netherlands [email protected] RD has received research funding from AstraZeneca, Svelte Medical, Osprey Medical, and Guerbet. JJP has received grants and personal fees from Miracor and Abbott Vascular. 1
2 3
4
5
6
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8 9
10
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. Campeau L. Percutaneous radial artery approach for coronary angiography. Cathet Cardiovasc Diagn 1989; 16: 3–7. Jolly SS, Yusuf S, Cairns J, et al, for the RIVAL trial group. 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. Valgimigli M, Gagnor A, Calabró P, et al, for the MATRIX Investigators. Radial versus femoral access in patients with acute coronary syndromes undergoing invasive management: a randomised multicentre trial. Lancet 2015; 385: 2465–76. 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: 430–36. Feldman DN, Swaminathan RV, Kaltenbach LA, et al. Adoption of radial access and comparison of outcomes to femoral access in percutaneous coronary intervention. Circulation 2013; 127: 2295–306. 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; published online Sept 25. http://dx.doi.org/10.1016/S01406736(15)00305-0. Kuipers G, Delewi R, Velders XL, et al. Exposure of cardiologists from interventional procedures. Radiat Prot Dosimetry 2010; 140: 259–65. Pancholy SB, Joshi P, Shah S, Rao SV, Bertrand OF, Patel TM. 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; 9: 1189–96. Delewi R, Hoebers LP, Råmunddal T, et al. Clinical and procedural characteristics associated with higher radiation exposure during percutaneous coronary interventions and coronary angiography. Circ Cardiovasc Interv 2013; 5: 501–06.
www.thelancet.com Published online September 25, 2015 http://dx.doi.org/10.1016/S0140-6736(15)00306-2