Radial Access Doubled for Left Main PCI in the UK Between 2007 and 2014

SAN DIEGO, CA—The radial artery has not only become the principal access site for left main PCI in England and Wales in contemporary practice, but the cases performed using transradial access also have become more complex, according to new registry data.

“Conversion over time to a predominantly radial strategy reduces the total vascular complications, major bleeding, and transfusions in the whole left main stem PCI cohort, and there was a trend for radial access to be independently associated with improved survival,” said Tim Kinnaird, MD (University Hospital of Wales, Cardiff), who presented the results today at TCT 2018.

For the study, Kinnaird and colleagues looked at more than 19,000 cases of unprotected left main PCI from the British Cardiovascular Intervention Society database completed between 2007 and 2014 in England and Wales. In line with previous research, they found the proportion of PCIs overall that were performed in patients with left main disease grew from 2.6% to 4.5% over the study period (P < 0.001 for trend). Also, femoral access dropped in the cohort of left main PCI patients from 77.7% to 31.7% (P < 0.001 for trend), mirroring similar trends observed in the overall PCI population. Notably, the percentage of cases done via the left radial artery grew from 0.8% to 5.2%.

Independent predictors of femoral access over the period 2012-2014 included:

• History of renal disease: OR 2.29 (95% CI 1.76-3.00)
• Restenosis indication: OR 1.69 (95% CI 1.27-2.26)
• CTO intervention: OR 1.66 (95% CI 1.25-2.12)
• Female sex: OR 1.56 (95% CI 1.35-1.79)
• Valve disease: OR 1.47 (95% CI 1.11-1.95)
• History of hypertension: OR 1.31 (95% CI 1.14-1.50)
• Left main intervention alone: OR 1.26 (95% CI 1.07-1.47)
• Diabetes: OR 1.25 (95% CI 1.08-1.46)
• Baseline disease per number of vessels: OR 1.14 (95% CI 1.07-1.21)
• Age, per year: OR 1.01 (95% CI 1.00-1.01)

Additionally, intravascular imaging and chronic anticoagulation were independent predictors of radial access use.

Over the entirety of the study, the proportion of patients with disease in the left main only who received radial access fell from 33.0% to 22.0%, but conversely those with disease in both the LM and proximal LAD and/or proximal circumflex saw increased use of transradial PCI (P < 0.001 for all trends). Likewise, patients who were treated transradially saw increased rates of imaging, rotablation, microcatheters, penetration catheters, and a greater number of stents (P < 0.001 for all trends).

“This data illustrates that cases done radially are more and more complicated as time continues and as experience is gathered,” Kinnaird told TCTMD.

Compared with patients treated via the femoral artery, those who received transradial access between 2012 and 2014 were less likely to have access site complications, access site bleeding, transfusion, in-hospital major bleeding, in-hospital death, and in-hospital MACE. There was no difference in mortality at 30 days between transradial and transfemoral access after adjustment.

Also, reductions were seen in arterial complications, arterial hemorrhage, major bleeding, transfusion, and in-hospital death among the whole cohort of patients receiving left main PCI—radial and femoral (P < 0.001 for trends). “People have argued that we do more and more radially and just leave more complex patients behind in the femoral cohort,” Kinnaird said. But these results show that the rate of a range of complications “are significantly improved as we transition from femoral to radial access.”

Lastly, Kinnaird showed that independent predictors of mortality at 12 months following left main PCI between 2012 and 2014 included acute kidney injury, age, chronic renal failure, ACS, valve disease, lower operator volume, and no use of intravascular imaging. There was also a trend toward higher 12-month mortality following transfemoral PCI.

At this point, the benefit of transradial over transfemoral access is fairly clear, Kinnaird told TCTMD. However, “the very high-volume default femoral operators can get pretty good results,” he said. “In the right hands, I think femoral is perfectly reasonable, but I think there are some things we know are going to be less [with radial] and that is length of stay, which we didn't present, and you're going to get less vascular complications, which is a big deal for most patients.”

Additionally, while femoral access might lead to good results, most patients prefer radial access, Kinnaird observed. “[It’s] a much more pleasant part of the world to go to and it's safer and [has] more rapid ambulation.” For operators who continue to prefer femoral procedures, he stressed proper screening and ultrasound guidance.

But What About Complex Lesions?

In discussion following the presentation, panel member Jens Flensted Lassen, MD, PhD (Rigshospitalet, Copenhagen, Denmark), complimented the researchers on their ability to map the caseload of such a large region, but said it is difficult to perform transradial PCI all of the time because he is often faced with the decision to use larger-bore catheters in complex patients—something which is not always possible with radial access.

“That's fair,” Kinnaird replied, adding that his institution sees “a fairly advanced population of disease” yet still performs radial PCI in at least 90% of their patients. “I think there is a group of patients who do need femoral—obviously CTO for dual catheter—but we do all our rotablation radially. . . . What this illustrates is that a large percentage of left main PCI can be done radially.”

Panel co-chair Jeffrey Moses, MD (NewYork-Presbyterian/Columbia University Irving Medical Center, New York, NY), said he would have liked to see a more granular look at the anatomy of the patient population. “I would really like to know who needs femoral, and not having the anatomy I find is a struggle,” he said.

While this information is not available in the BCIS database now, Kinnaird told TCTMD it may soon be. “We are in the process of updating BCIS and changing it completely,” he said. “At the moment, there's 120 fields in it. There's going to be more, and we are going to analyze the data in a slightly different way.”

Lastly, panel member Robert Pyo, MD (Stony Brook University Hospital, NY), said he most often uses radial access when performing PCI but defaults to femoral for left main bifurcation lesions. He asked Kinnaird why he chooses to use transradial access in complex lesion subsets: “Is it the patient comfort or something else?”

Kinnaird said that “it depends what you value as your endpoint. If you think the most important endpoint is 12-month mortality, then based on this data you might argue there isn't a strong argument. But having spent a lot of time researching bleeding and vascular complications, it is a big deal for patients. . . . In terms of techniques and larger catheters, I suppose it might depend on what your default strategy in terms of what the bifurcation is. I still think the vast majority of cases can be done radially one way or the other. They won't be so easy, but I think the extra occasional difficulty is still worth the outcome.”