MIAMI — A new study presented today at TCT 2012 once again confirms the benefit of radial-access PCI for the treatment of ST-segment-elevation MI (STEMI) patients [1]. Among individuals presenting to the hospital within 12 hours of STEMI, radial-access PCI was associated with a lower rate of major bleeding and access-site complications, as well as a significant increase in net clinical benefit.

"What was also interesting was that the contrast volume and [intensive care unit] ICU stay were significantly lower in the radial group," said lead investigator Dr Ivo Bernat (University Hospital, Pilsen, Czech Republic) during a press conference announcing the results.

With these positive results, the investigators conclude that the radial artery should be the preferred access route over the femoral artery in primary PCI. The lone caveat, however, is that these results were obtained by experienced radial-access operators. In this present study, known as STEMI-RADIAL, the interventional cardiologists all performed more than 80% of their procedures via the radial artery.

Dr James Hermiller (St Vincent Heart Center of Indiana, Indianapolis), a high-volume operator who was not affiliated with the study, said that radial-access primary PCI remains a challenge in the US because operator volume, in general, tends to be low, with relatively few primary PCIs done per doctor. "So trying to translate the high-volume master radialist approach as presented in this study is going to be a challenge," said Hermiller. "What will move the needle more than anything is that as fellows come out of this country they are trained with radial expertise."


The study included 707 STEMI patients randomized to primary PCI via the femoral (n=359) or radial (n=348) artery. There was no difference in baseline patient and procedural characteristics or differences in symptoms-to-balloon time. In addition, there was no significant difference in the use of anticoagulants. All patients received aspirin, clopidogrel, and heparin, and 45% of patients in both treatment arms received GP IIb/IIIa inhibitors.

During clinical follow-up, the rate of 30-day bleeding (defined by HORIZONS-AMI bleeding criteria) and access-site complications were 80% lower in patients treated via the radial artery (7.2% in the femoral group vs 1.4% in the radial group; p=0.0001). The 30-day net adverse clinical event rate, which included major adverse cardiac events (MACE) plus major bleeding, was 58% lower in the radial-access PCI arm (11.0% vs 4.6%; p=0.0028). There was no difference in the MACE rate alone. Less contrast volume was used in radial-access PCI, and the length of ICU stay was 0.5 days shorter in the radial-treated patients (3.0 days in the femoral group vs 2.5 days in the radial group; p=0.0016).

Overall, the mortality rate in RADIAL-STEMI was 2.3% in the radial-access PCI arm and 3.1% in the femoral-access arm, a nonsignificant difference that Bernat said was likely the result of the study being underpowered for death.

Switched Over to Radial PCI Seven Years Ago

Until seven years ago all the operators at Bernat's hospital were performing PCIs via the conventional femoral artery. Given the switch to radial access, they sought to assess bleeding and access-site complications among their center and three others performing a majority of their PCIs via radial access. When the study was initiated in 2009, there were no published data on the benefits or risks of radial-access PCI. Since then, RIVAL and RADIAL-STEACS have now been published.

With RIVAL, the largest study of radial-access PCI to date, the treatment of patients with acute coronary syndromes (ACS) with PCI via the radial artery did not reduce the rate of death, MI, stroke, or non-CABG-related major bleeding at 30 days. Transradial access, however, did result in a 63% reduction in the risk of large vascular-access complications. RIVAL included 7021 patients, of whom 1958 presented with STEMI.

Speaking with the media at TCT 2012, Bernat said that radial-access experience in RIVAL was quite variable compared with STEMI-RADIAL. Asked about the applicability of the findings, he added that the learning curve for radial-access PCI is not as steep as some physicians think and that most centers could make the switch to radial-access primary PCI once they become familiar with performing elective procedures via the radial artery.

"I think the findings are consistent with what we know about radial vs femoral PCI," added Dr Robert Byrne (Deutsches Herzzentrum, Munich Germany), another interventionalist who commented on the study. "If there is a benefit to be seen, it's in patients with STEMI. I think this certainly focuses our attention that perhaps a lot of the difference is in the anticoagulation strategies that are used in these patients."