Radial vs. Femoral Angioplasty: Still RIVALs

NEW ORLEANS, LA—In the largest randomized trial to compare transradial and transfemoral access, researchers demonstrated that while the 2 approaches show similar overall safety and effectiveness, the radial approach for angiography and percutaneous coronary intervention (PCI) yields lower vascular complications and may be preferred at high-volume centers and for ST-segment elevation myocardial infarction (STEMI).

Results from the study, which was published simultaneously online in the Lancet, were presented during a late-breaking trial session at the annual American College of Cardiology Scientific Session/i2 Summit on April 4, 2011.

For the RIVAL (RadIal Vs. femorAL) trial, researchers led by Sanjit S. Jolly, MD, MSc, of Hamilton General Hospital (Hamilton, Canada), randomized 7,021 ACS patients undergoing coronary angiography for possible intervention at 158 hospitals in 32 countries to radial (n = 3,507) or femoral (n = 3,514) access. Operators in each group performed 300 PCI procedures per year, with radial accounting for 40%.

The primary composite outcome of death, MI, stroke, and non-CABG major bleeding was similar between the 2 groups at 30 days, as were each of the component endpoints and stent thrombosis (table 1).

Table 1. Outcomes at 30 Days

 

Radial
(n = 3,507)

Femoral
(n = 3,514)

P Value

Death, MI, Stroke, Major Bleeding

3.7%

4.0%

0.5

Major Bleeding

0.7%

0.9%

0.23

Death

1.3%

1.5%

0.47

MI

1.7%

1.9%

0.65

Stroke

0.6%

0.4%

0.30

Stent Thrombosis

0.7%

1.2%

0.14


Major vascular access site complications, however, were reduced with radial access (1.4% vs. 3.7%; P < 0.0001), driven by decreases in large hematoma (1.2% vs. 3.0%; P < 0.0001) and pseudoaneurysm requiring closure (0.2% vs. 0.6%; P = 0.006).

In terms of procedural outcomes, radial access required longer fluoroscopy times, but rates of PCI success were similar, as were procedure time and length of stay. And more patients preferred their next procedure to be via the radial route (table 2).

Table 2. Procedural Outcomes

 

Radial
(n = 3,507)

Femoral
(n = 3,514)

P Value

Fluoroscopy Time, min

9.8

8.0

< 0.0001

PCI Success

95.4%

95.2%

0.83

PCI Procedure Time, min

35

34

0.62

Hospital Length of Stay, days

4

4

0.18

Patient Preferred Next Procedure to Be Radial

90.2%

50.7%

< 0.0001


In subgroup analysis, radial PCI lowered the primary composite endpoint in patients treated at centers in the upper tertile of radial volume (median operator volume > 146 radial PCI/year; 1.6% vs. 3.2%; P = 0.015) and in patients with STEMI (3.1% vs. 5.2%; P = 0.026). Mortality was also reduced in STEMI patients (1.3% vs. 3.2%; P = 0.006).

Two-thirds of the patients in each arm received PCI, while 28% had STEMI and 32% were treated at a high-volume center.

“Interventional cardiologists can feel reassured that both radial and femoral approaches are safe and effective in the current era,” Dr. Jolly concluded. “With increasing experience, this actually may improve the outcomes of radial access, and I think this is intuitive, the more you do the better you get. Finally, clinicians and patients may choose radial access because of its similar efficacy and its reduced vascular complications.”

Major Bleeding Defies Expectations

The biggest surprise of the trial was the lack of difference in major bleeding, which is thought to be lower with radial access. “We expected to see a larger reduction,” Dr. Jolly said.

The researchers offered several reasons in the Lancet paper, starting with the fact that the rate of major bleeding was extremely low in the femoral arm, implying that operators were highly experienced at that technique. In addition, the majority of the major bleeding events were at non-vascular access sites, such as gastrointestinal or intracranial. Bleeds at these sites would not be altered by the method of angiography, the researchers explained.

In an e-mail communication with TCTMD, Gregg W. Stone, MD, of Columbia University Medical Center (New York, NY), agreed that, “contrary to what had been widely anticipated, surprisingly, major bleeding and transfusions were NOT decreased with the radial approach. Rather, only local hematomas were reduced with radial intervention, and we have shown previously that while non-access-site bleeds and those requiring transfusions are strongly associated with subsequent mortality, local hematomas are not.”

‘No Mandate’

Nevertheless, “RIVAL is an important study that settles many issues that have been hotly debated among the ‘radialists vs. femoralists,’” Dr. Stone said. “Bottom line—both approaches are acceptable for PCI, and operators should use whichever approach they are most comfortable with, with no ‘mandate’ arising from this study for either radial or femoral access.”

In an editorial accompanying the Lancet paper, Carlo Di Mario, MD, PhD, and Nicola Viceconte, MD, both of Royal Brompton Hospital (London, United Kingdom), noted that “the most compelling result in favor of radial angioplasty is the mortality reduction for PCI during STEMI,” although this finding was not strong enough to effect any changes to current guidelines.

Still, “[a]fter this study, there is little justification to ignore one of the main developments in interventional cardiology and stubbornly refuse to embrace a technique likely to reduce minor adverse events (but in patients with STEMI, possibly also major adverse events and mortality) and improve patients’ comfort,” they write. “Especially, operators with a high workload of acute procedures should seriously consider retraining in radial angioplasty, and all new trainees should be taught and become proficient with this approach.”

Patient Preference Could Drive Change

Dr. Jolly offered this advice to clinicians: “Practice makes perfect. You really need to do a high volume of these radial procedures.”

Panel member Alexandre Abizaid, MD, PhD, of the Instituto Dante Pazzanese (São Paolo, Brazil), though, was not satisfied. “Is this trial going to change practice in the United States?” he asked.

“The short answer is time will tell,” Dr. Jolly responded. “Patient preference could lead to differences in referral patterns, and in this free market economy, that could be a driver for change.”

 


Sources:
1. Jolly SS, Yusuf S, Cairns J, et al.
Radial versus femoral access for coronary angiography and intervention in patients with acute coronary syndromes (RIVAL): A randomised, parallel group, multicentre trial. Lancet. 2011;Epub ahead of print.

2. Di Mario C, Viceconte N. Radial angioplasty: Worthy RIVAL, not undisputed winner. Lancet. 2011;Epub ahead of print.

 

Disclosures:

  • The study was funded by Bristol-Myers Squibb, the Canadian Network and Centre for Trials Internationally, the Population Health Research Institute, and Sanofi-Aventis.
  • Dr. Jolly reports receiving institutional grants from Bristol-Myers Squibb, Medtronic, and Sanofi-Aventis and consulting fees from AstraZeneca, GlaxoSmithKline, and Sanofi-Aventis.
  • Drs. Di Mario and Viceconte report no relevant conflicts of interest.
  • Dr. Stone reports serving on the scientific advisory boards for Abbott Vascular and Boston Scientific and as a consultant for Medtronic.

 

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