The Radial Revolution

Physicians are finding radial the access of choice in most cardiac cath cases.

Illustration © Lisa Clark

Radial artery access for diagnostic coronary angiography and PCI as an alternative to femoral artery access has been used internationally for 2 decades and may be gaining momentum in the United States. Mounting evidence supporting benefits, such as reductions in bleeding complications and mortality, is driving many physicians worldwide to predominantly use the radial access approach and to adopt the idea that radial access should become the standard of care and first-line approach in most cases.

“The data support a ‘radial first’ approach in most patients,” said Sunil V. Rao, MD, associate professor of medicine at Duke University Medical Center, Durham, N.C. “If there are two therapeutic approaches (eg, radial and femoral) and one is associated with lower rates of complications, then it should become the default strategy. Radial is such a strategy.”

Rao began using the radial artery access approach about 7 years ago due to a case where a patient’s aorta was occluded. He was forced to perform the case using the radial approach with very little experience and later resolved to do at least one radial case per day.

In the time since, he said, “Our cardiology fellows quickly realized the benefits as they could go home earlier since the radial sheath is removed at the end of case unlike femoral sheaths that had to stay in for a few hours then be removed. We are now using [the] radial approach in more than 90% of cases.”

Gilles Montalescot, MD, PhD, professor, Institut de Cardiologie, Hôpital la Pitié-Salpêtrière, Paris, also primarily uses the radial approach.

“This is my preferred access, which I use in more than 95% of elective cases and more than 90% of primary PCI patients,” Montalescot said. “It is more comfortable for patients, physicians and nurses.”

Similarly, Morton J. Kern, MD, professor of medicine, chief of cardiology, Long Beach Veterans Administration Hospital and associate chief of cardiology, University of California, Irvine, Irvine Medical Center, said that at both of his institutions, radial access is used in 80% or more of the cases. The fellows he works with are also embracing the new technology.

“The new fellows who are coming out of training will distinguish themselves through their ability to perform both methodologies and provide better outcomes of care for patients undergoing cardiac catheterization with the radial approach,” Kern said.

“I use radial access as my default approach, and patients request it. I use radial access during primary PCI for STEMI, but I would only recommend this in operators experienced with radial access,” said Sanjit S. Jolly, MD, assistant professor, interventional cardiologist, Hamilton Health Sciences, McMaster University, Hamilton, Ontario, Canada. “It is interesting that our cardiology trainees are now much more comfortable puncturing the radial artery than the femoral.”

Olivier F. Bertrand, MD, PhD, interventional cardiologist, Quebec Heart-Lung Institute, Quebec City, and associate professor, Laval University, said he has been working for the past 10 years toward the goal of seeing the radial approach become the standard of care. “For 12 years, I have been using the radial artery as the default access in more than 99% of cases,” Bertrand said.

Bertrand was traveling in China to increase the use of radial access there when reached for this interview.

Use of the radial approach is already the standard of care in many centers in Europe, Asia and Canada. This technique deserves more teachers, especially in countries with limited penetration, Montalescot said.

The Learning Curve

One of the challenges the interventional cardiology community in the United States and elsewhere faces is learning the procedural differences between transradial and transfemoral catheterization techniques and gaining experience in clinical practice.

“When starting a radial program, all cath lab staff should be on board and educated about all of the advantages,” said Nader Elgharib, MD, assistant professor of medicine at the University of Vermont, and interventional cardiologist at the affiliated hospital Fletcher Allen Health Care.

“I’ve been using the radial approach as my primary access for more than 3 years now,” Elgharib said. “I started the radial program at our institution, and our overall volume has increased dramatically from less than 1% to more than 20% in fewer than 3 years. Most of my colleagues have been enthusiastic about this approach. The nursing staff and the patients like it as well.”

However, there are important differences in practice with the transradial approach compared with the transfemoral.

“There are anatomical anomalies such as loops that occasionally need to be dealt with,” Rao said. “In addition, subclavian tortuosity can present a challenge. With respect to engaging the coronary arteries, the bulk of the challenge lies with engaging the left coronary. Most of the catheters that are available today for angiography and intervention are designed for the femoral approach. Universal radial curves are now available, and these can often facilitate radial procedures.”

There are additional differences that explain the learning curve.

“The biggest difference in technique begins with the access of the radial artery,” Kern said. The radial artery is only about 2 mm to 3 mm in diameter compared with the femoral artery that is about 6 mm to 8 mm in diameter, which is easily palpable and accessed with a needle. This is a difference in technique that can be overcome with experience, Kern said. “We are training our fellows to use ultrasound-guided radial access, and they are meeting with great success in making this procedure very acceptable and easy.”

The second major difference Kern mentioned is in the negotiation of catheters around the shoulder, into the brachiocephalic trunk and into the ascending aorta. This catheter manipulation is not necessary with femoral access, but it is a technique that has to be appreciated with the radial approach, and often the use of a deep breath is all that is required to get the catheter to go into the central position.

Another global difference is in the closure method, in which a small radial band can be put on at the end of the procedure as opposed to using manual compression of the groin or a femoral closure device in the groin, requiring the patient to lay flat, Kern said.

Elgharib also discussed the differences in the puncture site and catheters used.

“In contrast to the femoral approach, the radial artery can be punctured using a single anterior wall or double wall stick (posterior wall),” he said. “The radial artery is then cannulated with the Seldinger technique. Catheters are advanced similar to the femoral approach over a 0.035” guidewire. Because of the nature of the aortic curvature, left radial catheters should be downgraded by 0.5 (eg, using JL3.5 instead of JL4 used for left coronary cannulation). For the right coronary artery, that is not necessary most of the time and JR4 or modified AR can do the job. Specialized catheters can be used to cannulate both the right and left coronary arteries and are helpful to avoid frequent catheter exchanges. For coronary interventions, most of the standard catheters used from the femoral approach can be used and provide adequate support to successfully perform the interventions in the vast majority of cases.”

The Realization of Radial Approach Benefits

Studies have consistently shown that radial approach is associated with fewer vascular complications, lower access site bleeding and greater patient satisfaction, Rao said. “The studies also suggest that there is a mortality benefit in high-risk patients such as those with STEMI. Finally, this reduction in complications has translated into cost savings in some studies,” he said.

Specifically, in a systematic review of randomized trials comparing radial with femoral access published in June by Circulation: Cardiovascular Quality and Outcomes, researchers found that radial catheterization was associated with a $275 reduction in costs per patient from the hospital perspective, while it also reduced major complications, major bleeding and hematoma compared with femoral catheterization.

According to Kern, the greatest advantage is in the control of bleeding access site problems followed by patient comfort due to the ability to ambulate early and sit up, reducing problems related to being confined following a femoral approach.

In a late-breaking trial presentation at Transcathether Cardiovascular Therapeutics 2011, researchers presented data on the prospective, multicenter RIFLE-STEACS study. Lead author, Enrico Romagnoli, MD, PhD, of Policlinico Casilino, Rome, and colleagues found reduced bleeding complications and lower mortality in the treatment of patients with STEMI when radial access was used compared with the femoral approach.

In the RIVAL study, an international, multicenter trial, Jolly and colleagues found similar rates of the primary outcome, a composite of death, MI, stroke or non-CABG-related major bleeding at 30 days, between both approaches in patients with ACS (radial, 3.7% vs. femoral, 4%; P=.50). However, radial access was superior in reducing major vascular access site complications, which included large hematomas at the access site, pseudoaneurysms, arteriovenous fistulas and other vascular site surgical repairs (radial, 1.4% vs. femoral, 3.7%; P<.001).

“With regards to RIVAL, it is important to mention that we observed a particular benefit in high-volume radial centers with radial compared with femoral access for the primary outcome. This is an important message — that with a procedural innovation, volume is likely important (ie, the more you do, the better you get),” Jolly said.

The currently under way SAFE-PCI for Women trial is a multicenter investigation, which is being coordinated by the Duke Clinical Research Institute. It is comparing the transradial approach with the transfemoral approach in PCI among women, a population at increased risk of bleeding from femoral access and reduced procedural success from the radial approach.

“The radial approach offers multiple advantages; the main advantage is virtually eliminating access site bleeding. Some data suggest that lower bleeding complications might lead to a decrease in mortality, mainly in women,” Elgharib said.

Potential Complications

The radial approach remains an invasive technique, therefore traditional complications might still occur, Bertrand said.

However, radial access is resulting in fewer complications, according to the physicians interviewed. Complications noted as rare and easily managed involve hematoma, radial artery spasm, pseudoaneurysms and fistulas. A catheter can be tied into a knot and get stuck in the arm or the leg. Some patients can have a gastrointestinal bleed from anticoagulation, which can also happen with either the radial or femoral approach. “Compartment syndrome in the arm may be the worst possible and rarest complication that can occur,” Kern said.

Another specific issue, and perhaps the most common, is radial artery occlusion post-catheterization. “This occurs in about 5% of patients and is usually asymptomatic,” Bertrand said.

“By using best practices, the rate of radial artery occlusion can be decreased to less than 1%,” Rao added.

A study conducted by Ivo Bernat, MD, and colleagues evaluated the safety and efficacy of transient ulnar artery compression in patients with acute radial artery occlusion (RAO) after transradial artery catheterization. Although usually an asymptomatic complication, RAO can prevent additional radial access for staged or repeat procedures, researchers wrote. The study concluded that after transradial catheterization, acute RAO can be recannalized by early 1-hour homolateral ulnar artery compression. Transient ulnar artery compression was found to be safe and effective in patients taking very-low- and low-dose heparin. The incidence of final RAO remained significantly lower after a higher anticoagulation level, the researchers wrote.

In another study on the prevention of radial artery occlusion conducted by Samir Pancholy, MD, and colleagues, 218 patients underwent compression with documented patency of the radial artery, termed ‘‘patent hemostasis,” which was highly effective in reducing RAO after radial access. Researchers concluded that the occurrence of future RAO after radial access could be prevented with patent hemostasis and guided compression should be used to maintain radial artery patency at the time of hemostasis.

Some research has also shown that major bleeding remains significant in high-risk patients such as those with non-ST segment elevation acute coronary syndrome (non-STEACS) and STEMI.

An analysis of major bleeding complications and its association with mortality at 30 days derived from ABOARD study data concluded that major bleeding (primarily occult and gastrointestinal) remained a common complication in intermediate- to high-risk patients with non-STEACS receiving PCI and treated with triple antiplatelet therapy. The radial access approach was used in most patients (84%). Guillaume Cayla, MD, PhD, and colleagues concluded that despite significant reduction in access site bleeding with the use of radial access, the rate of major bleeding complications at 30 days remained significant.

Olivier Barthélémy, MD, and colleagues studied bleeding complications in patients with ongoing STEMI treated with aggressive antithrombotic treatment and routine primary PCI in which radial access (88%) and abciximab (Reopro, Centocor; 78%) were the default strategies. Researchers found that clinically important bleeding complications in this high-risk population are not uncommon, and the most frequent bleeding site was gastrointestinal. In addition, radial access primary PCI was a strong independent predictor of survival at 1-year follow-up in this population (OR=0.33; 95% CI, 0.17-0.56).

Rao added that rare events such as radial artery dissections and perforations are best treated by continuing the procedure since the presence of the catheter inside the artery acts as an internal compression device. “Other complications that we are starting to see now include radial arteritis, which manifests as forearm pain with a normal pulse. Ultrasound may show sub-occlusive thrombus in the radial artery. This is usually self-limited and can be treated successfully with NSAIDs or a short course of steroids,” he said.

When to Use Femoral Access

There are instances when the femoral approach would continue to be preferred to radial. All cath lab operators have to be comfortable with both approaches, Kern said.

“Any procedure requiring large bore catheters, like transcatheter aortic valve replacement, would need a femoral approach. Another situation is when both radial arteries are occluded,” Rao said.

A patient on hemodialysis with fistulae, shock patients requiring femoral access for intra-aortic balloon pump or any other cardiac support, and a case with a need for a large catheter (7F) would still take the femoral approach, according to Montalescot.

Kern also mentioned certain select subgroups in which his program is continuing to use the femoral approach until more data are available. These include patients on dialysis who may need the other arm for access, patients with bypass surgery in whom Kern does not feel comfortable using the left radial approach and patients who have very poor circulation to the hand.

Radial approach should be avoided if the patient has a negative modified Allen’s test. Rarely, the operator may have to switch from radial to femoral approach if the patient has severe aortic arch tortuosity that precludes adequate selective engagement of the coronary ostium or if there is lack of support when performing a complex coronary intervention, Elgharib said.

The Frontier of Radial Access

For Kern, the present state of interventional cardiology represents the frontier of radial artery access.

“I am a big fan of teaching both techniques, and if you are good with the radial, you will likely be very good with the femoral,” Kern said. “This is the frontier of radial artery access: We are learning how to do it quicker, better and that the benefits are highest in STEMI patients and those with the most intense anticoagulation.” – by Suzanne Bryla

Olivier F. Bertrand, MD, PhD, can be reached at the Quebec Heart and Lung Institute, Laval University, 2725 Chemin Sainte-Foy, Quebec City, Québec, Canada G1V 4G5; email: olivier.bertrand@criucpq.ulaval.ca.

Nader Elgharib, MD, can be reached at the University of Vermont, 85 S. Prospect St., Burlington, VT 05401; email: nader.elgharib@uvm.edu.

Sanjit S. Jolly, MD, can be reached at the Division of Cardiology, McMaster University, 1280 Main St. W., Hamilton, Ontario L8S 4K1; email: jollyss@mcmaster.ca.

Morton J. Kern, MD, can be reached at Long Beach Veterans Administration Hospital, 5901 E. Seventh St., Long Beach, CA 90822; email: mkern@uci.edu.

Gilles Montalescot, MD, PhD, can be reached at the Institute of Cardiology, Hôpital Pitié - Salpêtrière, 47 Boulevard of the Hospital, 75013, Paris, France; email: gilles.montalescot@psl.aphp.fr.

Disclosure: Bertrand has received research grants from Bristol-Myers Squibb, Cordis, Eli Lilly, Eurocor, GE Healthcare and Sanofi-Aventis, and has consulted for AstraZeneca, Cordis and Opsens; Elgharib is a consultant for Terumo Corporation; Jolly has received grant support from Medtronic; Kern is a consultant for Merit Medical Systems, St. Jude Medical and Volcano Therapeutics; Montalescot reports no relevant financial disclosures; Rao is a consultant for Terumo Medical and The Medicines Company.