LOS ANGELES – Radial-artery access for percutaneous coronary interventions finally took off in the Unites States starting about 3 years ago, rising from a steady rate of less than 2% of all American coronary interventions done through early 2009 to more than 11% of all coronary procedures by the third quarter of 2011, according to a nationwide registry.
Registry data from more than 2.2 million PCIs done during January 2007–September 2011 also confirmed better safety for PCI with a radial-artery approach, with bleeding and vascular complication rates substantially below those of patients who underwent PCI via a femoral approach. In addition, procedural success showed a small but statistically significant benefit in favor of radial entry for PCI, Dr. Dmitriy N. Feldman reported at the annual scientific sessions of the American Heart Association.
But these advantages seen in observational data plus the rising use of radial access come against a backdrop of radial access’ failure to show any safety or efficacy advantage over femoral access in the largest randomized trial to compare the two approaches, published in 2011.
"The biggest and best randomized, controlled trial that compared femoral and radial for PCI, the RIVAL [Radial Versus Femoral Access for Coronary Angioplasty and Interventions in patients with Acute Coronary Syndromes] trial, showed absolutely no difference in bleeding or clinical outcomes," commented Dr. Eric R. Bates, an interventional cardiologist and professor of medicine at the University of Michigan in Ann Arbor (Lancet 2011;377:1409-23). Seeing differences in the registry data reported by Dr. Feldman "is a classic observational-trial effect. It could all be because of confounding and selection bias," Dr. Bates said in an interview.
Dr. Eric Bates
The registry data reported at the meeting also documented a continued split among U.S. cardiologists in their use of radial-artery PCI: 20% of the 1,315 U.S. hospitals that contributed data to the registry during the study years did not perform any radial-access procedures, while 13 hospitals (1% of the total) used radial-artery approaches for more than half the PCIs they performed, said Dr. Feldman, an interventional cardiologist at New York-Presbyterian Hospital and Weill Cornell Medical School in New York.
Results from a second study reported at the meeting confirmed the superior safety of radial-artery PCI compared with femoral-artery access in a review of more than 750 patients treated at Ohio State University before and after a program-wide switch to radial-artery access as the default approach for elective PCIs, said Dr. Quinn Capers IV, an interventional cardiologist at Ohio State in Columbus. His comparison of complication rates during a period when few patients underwent PCI by a radial approach with a period shortly after when half the patients had the radial approach showed that this changeover to radial use linked with a greater than 75% drop in the rate of post-PCI myocardial infarctions and cuts by about two-thirds in the rate of blood transfusions and the rate of major access-site complications, Dr. Capers said.
American use of radial-artery PCI began rising sharply in late 2009 because of a "tipping point at that time," commented Dr. Jennifer Tremmel, an interventional cardiologist at Stanford (Calif.) University. "It was driven by fellows. Our fellows [at Stanford University] can now do both radial and femoral access" equally well, which allows them to better match their approach to what works best for the patient and for the procedure the patient will undergo.
"Most coronary interventions today can be done through the radial artery, while other procedures, like transcatheter aortic-valve replacement, use devices that are too large to go through the radial," said Dr. Ian C. Gilchrist, an interventionalist and professor of medicine at Penn State Hershey (Pa.) Medical Center. "There is a best approach for each procedure, but as equipment gets smaller and smaller I think you’ll see less and less of a role for femoral access for routine coronary work.
"Once you get into a period of rapid uptake [with radial-access PCI] it continues until you get up to 70% or 80%," Dr. Gilchrist predicted. "My guess is that radial will continue to rise [in the United States] until it far exceeds the transfemoral approach. That’s been the experience worldwide.
"In the United States there was a 10-year love affair with closure devices; that’s probably why radial didn’t kick up right away. But closure devices are at least $300 apiece, and they have never been shown to make a difference in outcomes. In my mind, transradial is a game changer," Dr. Gilchrist said in an interview. "It’s not just a minor change in the access site. It allows you to really redesign the cath lab – you don’t need all the beds." And it provides a better platform for routinely performing elective PCIs on a same-day discharge basis.