Radial RIVALs Femoral Access, Especially in Women

Because women undergoing cardiac cath are at higher risk of vascular access site complications than men, they may benefit more from radial procedures, according to a study published in the April 20, 2015, issue of JACC: Cardiovascular Interventions.

The main RIVAL trial randomized 7,021 ACS patients undergoing angiography for possible intervention to radial or femoral access. At 30 days, there was no difference between the groups in the primary composite endpoint (death, MI, stroke, or non-CABG bleeding).

The prespecified subanalysis compared the 2 approaches in the 5,160 men (2,599 receiving radial access and 2,561 femoral) and 1,861 women (908 radial and 953 femoral). In these subgroups, the sexes were well matched in terms of baseline characteristics, presentation, and DES usage, but men were more likely to be treated with a glycoprotein IIb/IIIa inhibitor (GPI).

Among men and women, there were no differences between access sites in the primary composite endpoint and the composite of death, MI, or stroke. There were also no differences in reductions in ACUITY non-CABG bleeding and major vascular complications with a radial approach. However, women reaped a higher absolute benefit than men in major vascular complications (3.0% vs 2.1%; table 1).

Crossover to femoral access from radial was higher than in the other direction in both women and men (P < .0001 for both; P for interaction = .054). Among women, radial-to-femoral crossover occurred in 11.1%, for which the most common causes were radial artery spasm, radial artery loop, and subclavian tortuosity.

PCI success was high among both men and women irrespective of access site, with no differences in procedure time, fluoroscopy time, or in contrast volume used.

The great majority of women who had radial access (86.1%) noted that they would prefer repeat radial access, while only about half of those who had femoral access said they would prefer to repeat their procedure.

Overall, major vascular complications were higher in women than men (4.7% vs 1.7%; P < .0001). On multivariate analysis, female sex was an independent predictor of this outcome (HR 2.39; 95% CI 1.76-3.25) as were increased age, PCI vs no PCI, and use of GPIs. Additionally, predictors of radial-to-femoral crossover included female sex (HR 1.39; 95% CI 1.04-1.85), increased age, and previous CABG.

Several Caveats

“These data suggest that women undergoing coronary angiography for acute coronary syndrome may particularly benefit from the radial approach,” write Ellen C. Keeley, MD, MS, and Vertilio M. Cornielle-Caamano, MD, both of the University of Virginia School of Medicine (Charlottesville, VA), in an accompanying editorial.

However, they note several caveats. First, the analysis was not powered to assess the differences between men and women, especially since randomization was not stratified by sex. “Hence, it is possible that selection bias played a role in recruiting specific women (such as those with strong radial pulses) into the trial; such a bias would limit the applicability of these results to all women undergoing angiography,” the editorialists explain.

Next, operator experience with the radial technique was not included, and the main RIVAL analysis showed radial to be superior to femoral access only if performed by expert operators, they note.

Lastly, “the influence of choice of pharmacotherapy on vascular access site complications is not addressed by the present study, which left this choice to the operator’s discretion,” Drs. Keeley and Cornielle-Caamano write. “Because bivalirudin… has been shown to decrease bleeding in patients undergoing PCI, it is possible that the use of bivalirudin would negate the effect of vascular access site.”

The ongoing SAFARI-STEMI trial, which is randomizing men and women with STEMI to radial vs femoral access and requiring bivalirudin, “should help to tease out the relative effect of access site and choice of pharmacotherapy on bleeding complications in high-risk men and women undergoing PCI,” they say.

Radial Should Be the Default Approach for Women Too

Although the SAFE-PCI trial was terminated early and failed to meet its primary endpoint, the results are consistent with those of RIVAL, Robert W. Yeh, MD, MSc, MBA, of Massachusetts General Hospital (Boston, MA), told TCTMD in an email. However, “RIVAL has a significantly larger sample size of women undergoing PCI than SAFE-PCI did, and as a result had much more power to look at the specific benefit of transradial PCI in women,” he noted.

This additional evidence supports the proposition that “radial access should be the default approach for both women and men,” Dr. Yeh continued, adding that women especially “have higher rates of vascular complications than men, and this is the most effective strategy we have for reducing them.”

With that said, not all patients are candidates for radial access, Dr. Yeh said, citing those with inaccessible arteries, arteriovenous fistulas, and severe arterial spasm as likely to need femoral access.

“But there is a larger group of women for whom radial access might make the procedure take longer or more challenging to complete—patients with multiple bypass grafts, patients with chronic total occlusions requiring advanced techniques, for example,” he said. “Here, I think the benefits of radial versus femoral access are less clear and very operator-dependent. But we should all be making efforts to expand our ability to complete these types of complex procedures from the radial approach, so that the bleeding and vascular benefits can be gained by a greater number of women.”

Additionally, Dr. Yeh said, “Patient preference is very important, particularly when a procedure can be done in different ways and achieve essentially equivalent results with regard to PCI success.”

Sources:
1. Pandie S, Mehta SR, Cantor WJ, et al. Radial versus femoral access for coronary angiography/intervention in women with acute coronary syndromes: insights from the RIVAL trial (Radial Vs femorAL access for coronary intervention). J Am Coll Cardiol Intv. 2015;8:505-512.
2. Keeley EC, Cornielle-Caamano VM. Radial artery access in women undergoing percutaneous coronary procedures [editorial]. J Am Coll Cardiol Intv. 2015;8:513-514.

Related Stories:

• With Some Caveats, SAFE-PCI Shows Positive Signs for Radial Access in Women
• SAFE-PCI: Radial Artery Access Beneficial in Women
• State Registry Shows Radial PCI Rare but Beneficial