April 5th, 2011
RIVAL Trial Tests Radial Versus Femoral Access
Larry Husten, PHD
Radial access for angiography has gained increasing acceptance in recent years based on the promise of reduced complications and increased patient comfort. At the ACC, and in a simultaneous publication in the Lancet, Sanjit Jolly and colleagues presented the results from RIVAL, the largest trial to date comparing radial versus femoral access.
Some 7021 ACS patients about to undergo angiography were randomized to either radial or femoral access. The primary outcome – a composite of death, MI, stroke, or non-CABG-related major bleeding at 30 days – occurred in 3·7% of patients in the radial access group versus 4·0% of patients in the femoral access group (HR 0·92, CI 0·72–1·17; p=0·50).
However, in the following prespecified subgroups, radial access demonstrated a significant advantage over femoral access:
- in centers in the highest tertile of volume: HR 0·49, CI 0·28–0·87, p=0·015
- in patients with STEMI: HR 0·60, CI 0·38–0·94, p=0·026
Here are more overall results:
- The rate of death, MI, or stroke at 30 days was identical in both groups: 3.2%.
- The rate of non-CABG-related major bleeding at 30 days: 0·7% in the radial group versus 0·9% in the femoral group (HR 0·73, CI 0·43–1·23, p=0·23).
- Large hematoma at 30 days: 42 of 3507 in the radial group versus 106 of 3514 in the femoral group (HR 0·40, CI 0·28–0·57, p<0·0001).
- Pseudoaneurysm needing closure: 7 patients in the radial group versus 23 in the femoral group (HR 0·30, 95% 0·13–0·71, p=0·006).
In combination with results from previous trials, the data “show that radial access reduces major vascular complications compared with femoral access,” according to the investigators. “Percutaneous coronary intervention success rates seem to be similar. Both patients and clinicians might choose radial access because of its similar efficacy and reduced vascular complications.”
In an accompanying comment, Carlo Di Mario and Nicola Viceconte point out that although the highest-volume operators had better results with radial access, the group in the middle tertile had the worst outcome. In addition, they note that the radial approach did not reduce the hospital length of stay or the amount of contrast used. Nevertheless, they offer a cautious endorsement of the technique, writing that there is now “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. 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. Conversely, it is important not to demonise the femoral approach, which is more suitable when large guiding catheters are required and prolonged procedural time is expected for complex lesions, such as chronic total occlusions, some large bifurcations, and diffuse or very calcified lesions.”
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I’m at a loss to explain why the radial approach had better outcomes (combined death, MI, or stroke) than the femoral approach in patients with STEMI but not those with NSTEMI/ACS. Major bleeding rates were similar for both techniques.
Any hypotheses?