Less Bivalirudin, Minimal Ultrasound: Survey Highlights Global Transradial Practice Patterns

The past 8 years have seen considerable evolution in how interventional cardiologists perform transradial angiography and interventions, but there remains a wide variation in exactly how these radial-access procedures are performed across the globe.

In a new survey, investigators found that a relatively large proportion of operators, including those inside and outside the United States, do not adhere to “best practices.” For example, nearly 30% of clinicians do not routinely assess for radial artery patency after achieving hemostasis and just 63.2% of physicians checked for patency at the time of discharge. Additionally, there has been a shift toward greater use of heparin over bivalirudin, but many physicians give less than the required dose (5,000 units) needed to reduce the risk of radial artery occlusion, say researchers.   

“This is information that is difficult to get from randomized trials and even from registries,” lead investigator Adhir Shroff, MD (University of Illinois, Chicago), told TCTMD. “We wanted to gain some insight into what people do procedurally, but it’s hard to understand those technical aspects of a procedure-related field, to see how practitioners actually do things. We have learned, certainly in radial, that there are certain aspects studied in randomized trials where we found one method is better than another method, or one practice is better than another practice. There should be some convergence in terms of doing things in the best or safest way.”  

Shroff acknowledged that “best” is a loaded word and emphasized that the purpose of the survey was not to make value judgements. “It’s more from an outcomes’ perspective—there are certain practices that have less complications and a lot of what has driven radial access is the reduced risk of complications,” he said.

Greater US Participation in Second Survey

The international transradial survey, which was published November 19, 2018, in Catheterization and Cardiovascular Interventions, is the second survey conducted in the field. The first was published in 2010, a time when transradial access for angiography and PCI was still in its infancy in the US. In that first survey, fewer than 10% of operators surveyed performed procedures in the US, whereas in the latest survey nearly 40% of respondents practice stateside.  

Overall, there were 425 US operators who completed the survey and 640 from outside the US. Slightly more than 60% said they’d been in practice less than 15 years, including 22.4% who had fewer than 5 years in practice. Approximately 70% of all operators began performing transradial procedures between 2007 and 2015, more than half had done more than 250 diagnostic catheterizations in the past 12 months, and nearly 60% performed more than 101 interventional procedures in the past year.

In terms of some of the notable findings, investigators found that only a minority of operators perform routine noninvasive testing for dual circulation, although US operators were more likely to test compared with non-US physicians. To TCTMD, Shroff noted that testing for dual circulation has not been shown to predict the risk of future complications.  

“It’s an evolution,” said Shroff. “On average, in the US, physicians are earlier in their experience with radial access compared with those outside the US. So, in general, they tend to be more conservative. They might do things that other communities don’t do, such as Allen testing or Barbeau testing or noninvasive testing, before doing the radial procedure.”

That said, Shroff believes that a lot of radial-access operators, whether it’s with better technology or in response to newly published studies, are early adopters. “Obviously that’s a huge generalization, but I think it’s one of the reasons we see the changes in practice more quickly in this community. People seem to be more open to change,” he said.

Notable Changes Since 2010

Compared with 2010 practice patterns, one noticeable change includes the increased use of hydrophilic sheaths for the prevention radial artery occlusion. Another includes more operators using the contralateral radial artery rather than transitioning to the femoral artery if their initial access attempt fails. Additionally, the use of bivalirudin has declined. The overall use of bivalirudin was up—mainly because of the greater number of US respondents—but when analyzed separately, use of bivalirudin for both elective and urgent/emergent PCI procedures declined among US physicians from 2010.

“It’s interesting to see the changes in anticoagulation,” said Shroff. “It’s not all that unexpected, but based on some of the data that has come out showing that when you use radial access the choice of anticoagulation is not as important as when you use femoral access. We can see that adoption as physicians move away from a bivalirudin-based anticoagulation strategy and using more unfractionated heparin.”

The use of ultrasound—which can be used to increase “first pass” radial-access rates—was infrequent, with large differences between US and other operators. In the United States, 48.8% reported not using ultrasound guidance compared with 92.6% of non-US cardiologists.

Sheath selection also varied between US and global operators, but most chose 6-Fr catheter compatible sheaths for diagnostic and PCI procedures. The researchers note there is an underutilization of smaller sheaths (< 6-Fr) for diagnostic catheters and that larger catheters increase the risk of radial artery occlusion. Worries about exchanging sheaths if PCI is needed, which can lead to higher costs, might explain the use of the 6-Fr systems, they suggest.

To TCTMD, Shroff said the present survey sheds light on how interventional cardiologists are practicing medicine, and that he hopes the present study motivates and encourages operators to pay attention to best practices. The goal, as a physician and as a field, he said, is to keep evolving and to be “always trying to approach the optimal way to practice.”