Is Radial Artery Catheterization a Tempest in a Teapot?

Several timely articles in leading newspapers across the country are spotlighting the recent surge in radial artery cardiac catheterization. For example, Suzanne Hoholik wrote the article “Some surgeons inserting stents through the wrist” for the Columbus Dispatch (Sunday, January 30, 2011), and Ron Winslow wrote the article “Wrist May Be Route To Safer Heart Treatment” in the Wall Street Journal (February 8, 2011), providing the lay audience with the reasons why the radial approach in the United States is growing. Although there is a groundswell of favorable commentary and numerous recent publications in peer-review journals, some physicians say they don’t see the benefits of going through the wrist. Dr. Steven Nissen, chairman of cardiovascular medicine at the Cleveland Clinic, is quoted in the Columbus Dispatch article, noting, “…patients could lose the pulse in their wrist from the procedure or from scar tissue. My own view is, it’s a niche procedure; it’s just not important.” He continues, “Of all the things in medicine that are going on and innovative, it’s not in the top 100. The standard procedure works very well, and it’s safe, and we have excellent outcomes.” It is precisely this conventional wisdom (CW — and by the definition of CW, meaning often erroneous or outdated) that requires those of us who know the data and are garnering experience to continue to educate the cath lab physicians and staff about the clinical benefit of any new approach to a common practice. Still, it is fair to ask, “Is the interest in radial artery catheterization unimportant? Just a passing phase? Just a tempest in a teapot?” I don’t think so, and here’s why.

Conventional Wisdom is Wrong

The WSJ reported that “…cardiac catheterization is getting a makeover in the U.S., with a new approach (radial access) that proponents say is safer and more comfortable for patients and potentially cheaper.” That concisely sums it up and is why radial access is not just a fad. Numerous, well-done, recent studies such as those by Wu et al¹, Rao et al², Mann et al³, Kiemeneij et al⁴, and many others demonstrate superior outcomes for transradial compared to transfemoral percutaneous coronary intervention (PCI). In a specific, recent example, Wu et al1 reported their transradial and transfemoral outcomes for PCI. In 1,113 patients, they found that the transradial approach was associated with significantly reduced bleeding complications (12 vs. 38, p=0.002, with 0 vs. 7 at the access site, 1 vs. 16 for bleeding at access and other sites, p=0.03) and zero vascular complications. There was a trend for a lower observed in-hospital mortality rate with the transradial approach (0.87% vs. 2.24%, p=0.38). Same-day discharges were more common in the transradial patients (14.2% vs. 2.2%, pWhy Radial Cath is Difficult and What to Do About It On a personal note, I understand the reticence of many of my colleagues who share the opinion of Dr. Nissen, a non-invasive cardiologist, on the radial approach. Despite the data, they are committed transfemoraIists. In the 2 years since we began our transradial program, the feedback from patients and staff alike surprised us with overwhelmingly favorable responses. Most of the negative experience came from our own failures and from some of our colleagues, struggling to reconcile the procedural challenges with their daily, straightforward transfemoral practice. Despite the abundant and accumulating data indicating superior outcomes, like Dr. Nissen, they too were unimpressed. They discounted the bleeding issue that is mostly, if not exclusively, confined to the access site complications. Bleeding after cath should not be minimized. There is an important relationship between bleeding and mortality in PCI studies, especially evident in those addressing potent new anti-thrombin and anti-platelet agents. Our collegial transfemoraIists continue to point to their large and safe experience with thousands of cases over many years, conveniently forgetting the fortunately few patients that had a retroperitoneal hematoma and near-death experience. Every PCI physician has had to deal with a patient with a bleeding problem and wishes he didn’t. It is worth repeating that the common vascular complications related to high or low puncture sites, dissections, vascular closure device failure, and leg and back discomfort are not seen with radial access (use one grain of salt here). In defense of the traditional approach, the benefits of being a quick, easy and ‘safe’ method are mostly true, but this approach is inferior with regard to safety. While the transfemoralist would like to continue without change, the data speak about a better way. In all of medicine and especially cardiology, personal inconvenience should not trump better patient results. I understand the discomfort of learning a new approach. It is painful, but certainly worth it. I sympathize and recognize that beginning a new method of catheterization is associated with frustration, failure, and humility, but finally, success. I appreciate that the busy private practitioner, harried under the pressure of doing case after case, will not want to slow down and devote time and energy to becoming a skillful transradialist.

How to Start Learning Radial Cath

Given the situation of the busy practitioner, how should one start to learn radial access? Here was our experience. We began slowly, one case a day. Initially, we selected ‘easy’ patients, usually men with large radial arteries. We talked about the protocols and what we needed to do. We allocated a set amount of time to access, to crossing the tortuous aorta and to coronary cannulation. We failed in several of our first 10 cases due to problems we now know how to overcome. We accepted the fact that converting to the femoral approach was going to be part of the learning curve. While converting to femoral access is not a truly failed catheterization procedure, since we did complete the angiograms or PCI, we accepted the bruises to our egos. But for best patient care, we persisted. The arm set up became routine, access became easier, negotiating the shoulder, arch, and coronary seating became familiar and more successful. Use of the left radial helped for our coronary artery bypass graft patient studies. Our procedure failure dropped to 1 in 10. We learned what we could and could not do in the arm without harming the patient. Our default approach is now ‘radial first’ while keeping the femoral area prepared in case we needed to convert.

One Radiologist’s View of Radial Cath

For an unusual comment on radial cath, I ran across a blog statement on theheart.org from a radiologist. He wrote, “In over thirty years I performed over 1500 angiograms (arteriograms). I used the femoral artery location and never [his emphasis] experienced a significant hematoma or bleeding episode! Why? — Simple. During and after removal of the catheter I maintained and carefully monitored a graded amount of pressure directly over and slightly above the puncture access site, while checking status of the leg circulation. This required staying with the patient for 15 to 20 minutes. The patient was advised to stay horizontal for the next few hours and [was] advised to gradually resume activity over the following week.” He goes on, “Unfortunately, [in] today’s practice by physicians [they] just will not spend the time with the patient and use instead nurses without adequate experience, commercial pressure devices or simply walk away too soon without waiting, careful monitoring, etc. [There is] NO need for MDs to try the smaller more difficult to catheterize radial artery!” I was impressed when I read this. First, I have never met an invasive cardiologist who has never had a complication. Maybe this never happens to radiologists who do 50 arteriograms/year. Second, most of us know that bleeding does occur even when you spend considerable time with patients, and in spite of well-trained nurses and accurately placed closure devices. I must disagree with his last comment as well, for the many reasons above. Transradial cath has been neglected for too long in the world’s largest catheterization arena. While Dr. Nissen and many others fail to appreciate or outright ignore the data, ultimately it will be the informed and conscientious physician who will accept a superior technique with its forerunner taking up a secondary, but still important position, in the cath lab.

References

1. Wu C, et al. Transradial approach is associated with lower risk of adverse outcomes following percutaneous coronary intervention: a single-center experience. J Intervent Cardiol, in press, 2011.
2. Rao SV, Ou FS, Wang TY, et al. Trends in the prevalence and outcomes of radial and femoral approaches to percutaneous coronary intervention: a report from the National Cardiovascular Data Registry. JACC Cardiovasc Interv 2008 Aug;1(4):379-386.
3. 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;32:572-576.
4. 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;29:1269-1275.

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Article Update

Re: “How Should We Manage Nickel Allergy in Patients Needing Coronary Stents?” (Editor’s Corner, January 2011) Near the end of this January 2011 article, Dr. Kern reports being asked if one stent contains a greater amount of nickel than another. He responds, “When we asked the companies, it seemed that the bare metal stent from Medtronic contained less nickel than the [Abbott] Vision stent.” The Medtronic website offers a downloadable PDF called “Advantages of Cobalt Alloy for Coronary Stents” (Available at https://wwwp.medtronic.com/newsroom/content/1110132739468.pdf), which states that the chemical composition for the alloy in the Medtronic Driver stent (which is the same alloy used for Medtronic’s Integrity stent) has 35% nickel content. In comparison, the alloy used in the Abbott Vision stent has approximately 10% nickel content. For additional information on the metal composition of Abbott stents, please visit the Abbott Vascular website: (https://www.abbottvascular.com/static/cms_workspace/pdf/ coronary_intervention/xience/CoCr_Memo.pdf). Disclosure: Dr. Kern reports that he is a speaker for Volcano Therapeutics and St. Jude Medical, and is a consultant for Merit Medical and InfraReDx, Inc. Check out Dr. Kern’s latest book, “Notes from the Editor’s Corner of Cath Lab Digest” at www.mortonkernmd.com. Only $29.95!