High-Volume Transradial PCI Centers Do Not Lose Femoral Skills: BCIS Registry

The growing adoption of radial access for cardiac catheterization procedures has not compromised clinical outcomes when physicians opt for access via the femoral artery, new research shows.

In a large analysis of PCI procedures undertaken throughout England and Wales between 2007 and 2013, once differences in the case mix were adjusted for, investigators observed similar rates of vascular complications and 30-day mortality with transfemoral PCI at clinical centers that have shifted primarily to transradial access and those centers that have predominantly stuck with transfemoral-access PCI.

The conclusion, say researchers, is that increased use of radial artery does not lead to a loss of transfemoral proficiency.

“The sort of cases that we do femorally in centers that have transitioned to radial-artery access are usually very sick patients,” senior investigator Mamas Mamas, BMBCh (Keele University, Stoke-on-Trent, England), told TCTMD. “So, it’s not surprising that if you look at crude outcomes, the outcomes of these patients are going to be much, much worse than in centers that would normally do transfemoral PCI. The case mix is much more complex.”

In 2015, researchers at the Montreal Heart Institute published data suggesting that when interventionalists switch to the “radial first” approach, proficiency in transfemoral access declines. Compared with a historical cohort, the researchers observed a higher rate of vascular complications when they began to perform transradial PCI more frequently, a phenomenon they dubbed the Campeau radial paradox, named after Canadian transradial pioneer Lucien Campeau.

Mamas said their adjusted data, published February 14, 2017, in Circulation: Cardiovascular Interventions, should “put to bed” fears operators might lose their femoral skills when switching to transradial access. “Any way we looked at it, there was no compromise in centers that have switched to radial,” he said.

Sicker, Tougher to Treat Transfemoral Patients

In their study, Mamas along with lead author William Hulme, MSc (University of Manchester, England), and colleagues, analyzed data of 235,250 transfemoral-access PCI procedures undertaken at all 92 centers in England and Wales. During this time period, the uptake of transradial increased significantly. When stratifying clinical centers based on the volume of PCIs performed via the femoral artery, 53 were low-volume transfemoral centers (0 to 33% transfemoral cases) and 16 were high-volume transfemoral centers (> 66.7% of cases).

Any way we looked at it, there was no compromise in centers that have switched to radial. Mamas Mamas

Over time, the researchers observed that transfemoral PCI cases tended to be higher risk when undertaken at predominately transradial centers, with patients more likely to have cardiogenic shock, renal failure, previous CABG surgery, ACS, and require pre-PCI ventilation. The 30-day mortality rate with transfemoral PCI increased at the predominately transradial centers over time, but it was stable in centers that performed a high volume of transfemoral cases.

However, adjusting for the differences in case mix, there was no independent association observed between 30-day mortality rates and the recent volume of transfemoral cases per center or the proportion of cases performed via the femoral artery. Similarly, there was no significant association observed between vascular complications and proportion of transfemoral cases.

In the United Kingdom, adoption of transradial PCI has increased from approximately 14% in 2007 to more than 80% in 2015, said Mamas. If the Campeau radial paradox existed, they would have observed it in this large dataset from the British Cardiovascular Intervention Society (BCIS).

“I would advocate that people aren’t put off by individuals that perhaps would raise concerns where there isn’t one,” said Mamas. “The radial approach is supported by randomized controlled trials and by international and national best-practice guidelines. It’s a matter of patient safety. Patients should undergo the procedure through the radial approach.”

What About the Individual Operator?

In an editorial accompanying the study, Michel Le May, MD, and George Wells, PhD (University of Ottawa Heart Institute, Canada), argue that the analysis does have some limitations, specifically that no analysis was performed at the operator level. If some operators at a high-volume transradial center chose to remain transfemoral operators, then a mortality difference might not be evident at the hospital.

They also suggest the time period studied was limited and that becoming de-skilled in transfemoral access PCI might not be evident if hiring new interventionalists—those trained primarily with the transradial approach—was slow. Additionally, advances in transfemoral technologies—such as smaller sheath guiding catheters—might have offset the declining skill sets of the operators, something that was not factored into the analysis.

“[T]here is likely a threshold for operator and center transfemoral access volume below which skills are lacking to adequately perform PCI via this route,” write Le May and Wells. They believe, like the original researchers who first identified the Campeau paradox, that training programs include formal teaching and minimal transfemoral volumes to maintain proficiency and avoid complications.

Much of this fretting over femoral access skills seems to be unfounded. Sunil Rao

Sunil Rao, MD (Duke University Medical Center, Durham, NC), however, called the BCIS registry data an important contribution, saying the numbers address some of the “hand-wringing” over whether operators/fellows might lose their femoral-access skills as they adopt the radial-first approach. Like Mamas, he also cited some of the major limitations of the original paper that first raised concerns over the radial paradox, saying the current BCIS analysis addresses those drawbacks. 

“One thing that has not been pointed out is that the contemporary interventional cardiologist still does a lot of transfemoral procedures,” he commented in an email, specifically pointing to use of hemodynamic support and TAVR procedures. “So they are still keeping up their femoral access skills. So much of this fretting over femoral access skills seems to be unfounded.”

Similarly, Sanjit Jolly, MD (McMaster University, Hamilton, ON), told TCTMD the latest BCIS “analysis dispels the myth of the Campeau paradox,” specifically once the higher-risk case mix is factored into the risk modelling. For when physicians absolutely must use the femoral artery in high-risk patients, Mamas pushes for safer practice techniques, such as ultrasound guidance and micropuncture vascular access kits, to perform the procedure as safely as possible.