MIAMI—In STEMI patients presenting within 12 hours of symptom onset, the radial approach was associated with a significant lower incidence of major bleeding and access site complications and a significant better net clinical benefit, according to the late-breaking STEMI RADIAL trial, presented Oct. 26 at the annual Transcatheter Cardiovascular Therapeutics (TCT) conference.

In the STEMI-RADIAL trial, researchers examined the net clinical benefit of using the radial versus femoral approach in patients presenting within 12 hours of symptom onset of acute STEMI.

STEMI-RADIAL was a randomized, multicenter, parallel group trial conducted in 707 patients at four high-volume centers in Europe—348 patients in the radial group and 359 patients in the femoral group. All investigators performed more than 200 PCIs per year, and more than 80 percent of their cases were done with the radial approach.

Operator volume remains a large consideration for positive outcomes with the radial approach. However, presenter Ivo Bernat, MD, of University Hospital and Faculty of Medicine in Pilsen, Czech Republic, told Cardiovascular Business that the “learning curve shouldn’t be long. After a practice has been using the radial approach in elective patients for approximately one year, they should be able to start the approach in STEMI patients with good results.”

However, as a study discussant, James B. Hermiller, MD, of St. Vincent Heart Center of Indiana in Indianapolis, added that “operator volume in the U.S. is relatively low, and particularly in STEMI patients. Trying to translate the high-volume results found in this trial is going to be challenge, but what will move the needle in the U.S. is that new fellows are emerging with radial training.”

In the study, patients eligible for both access sites without cardiogenic shock were randomized to the radial or femoral access approach. The patients received either heparin or glycoprotein IIb/IIIa inhibitors, not bivalirudin. “This is an important point—not to distract from the importance of the study as a whole—because a lot of the differential is probably driven by IIb/IIIa inhibition,” said panelist William A. Gray, MD, of Columbia University Medical Center/New York-Presbyterian Hospital in New York City.

The primary endpoint was the cumulative incidence of major bleeding and vascular access site complications (requiring intervention) at 30 days. Secondary endpoints included major adverse cardiovascular events (MACE: death, reinfarction and stroke), technical success, access site failure, procedural and fluoroscopy times, contrast volume, intensive care stay and target lesion revascularization. The average door-to-balloon times in both groups were approximately 30 minutes.

The primary endpoint of major bleeding or access site complications occurred in 7.2 percent of the femoral access patients and 1.4 percent of the radial access patients. The rate of MACE at 30 days was 4.2 percent in the femoral access group, and 3.5 percent in the radial access group.

Moreover, the radial approach reduced significantly intensive care unit stay from three days to 2.5 days, as well as contrast volume (170 vs. 182) compared to the femoral approach.

In the STEMI population in the RIVAL trial, there was a mortality benefit, which was not seen in this trial. “The difference between RIVAL and our trial was not that great numerically, but a little different with the percentage, said Bernat. STEMI RADIAL was not powered to assess mortality also.  

“Our results support the use of radial approach in primary PCI in experienced radial centers as a first choice,” concluded Bernat.