Reed Miller

May 10, 2012

May 10, 2012 (Las Vegas, Nevada) — The meaning of the Radial vs Femoral Access for Coronary Intervention (RIVAL) trial results continue to stir spirited debate among interventionalists about the appropriate role of transradial- and transfemoral-access techniques in PCI.

In a staged debate here at the Society for Cardiovascular Angiography and Intervention 2012 Scientific Sessions, Dr David Cox (Lehigh Valley Hospital, Bethlehem, PA) decried the "zealotry" of self-described "radialists" who see the RIVAL results as a coup de grâce for the traditional transfemoral approach, even though the RIVAL results were mixed. In a head-to-head comparison in ACS patients, RIVAL showed the rates of death, MI, stroke, and non–CABG-related major bleeding at 30 days were about the same with either approach, but transradial access reduced the risk of large vascular-access complications, as reported by the physicians, by 63%.

"I daresay that we don't need that attitude," Cox said. "Interventionalists should perform PCI with the access route that they are most comfortable with that gains the best results for patients." Cox earned some applause from the large audience at the debate when he said, "We are all interventionalists, and we all need to be skilled in both femoral and radial approaches and do the right one for any given patient."

Dr Tift Mann (Wake Heart and Vascular Associates, Raleigh, NC) took the proradial side of the debate. "Radial PCI is a dominant strategy. It reduces access bleeding complications. It reduces mortality in STEMI when performed by experienced operators. It reduces hospital costs, and it's overwhelmingly preferred by patients," he argued.

Mann stressed that the Radial versus Femoral Randomized Investigation in ST Elevation Acute Coronary Syndrome (RIFLE STEACS) STEMI patients who were treated with the transradial approach had a significantly lower risk of bleeding and major adverse cardiac and cerebrovascular events, including 30-day death, compared with patients treated with transfemoral PCI. However, Cox pointed out that the same difference has not been demonstrated in non-STEMI patients.

Too much bleeding?

Mann's argument focused primarily on femoral access-site bleeding. He argued that the definition of bleeding in the RIVAL study was very restrictive and only counted life-threatening bleeds as major events. So most of the bleeding events recorded in the study were from sites other than the access route, and most of the real bleeding events were counted just as access-site complications, he said. But under what he considers a more reasonable definition of bleeding, like the TIMI definitions, most of the bleeding events would have been access-site bleeds, making the femoral results in RIVAL look a lot worse.

"In my interpretation of RIVAL, the femoral outcomes were biased, because there were clearly clinically significant femoral bleeding complications that were not included in the primary end point because of the restricted definitions, and perhaps equally important, there was mortality in the femoral group that was artificially low because late deaths beyond 30 days were not counted," Mann said. "If we've learned nothing else in the past decade, we know that bleeding from the groin causes problems. It's not a trivial event. It is a major issue and is potentially life-threatening, whether it's just a hematoma or a large retroperitoneal bleed. Also there is continued attrition after the first event. If you just determine the end point at 30 days, you're missing a number of events."

Cox agrees that access-site bleeding is an important adverse event but pointed out that mortality with the bleeds at sites other than the access site are twice that of the access-site bleeds. He added that in the roughly 17 000 patients in ACUITY and REPLACE 2, hematomas greater than 5 cm were not a predictor of mortality. "So even if you bleed from the groin with a hematoma, you don't die from that," he said. "And I've never seen anyone die from AV fistula or a pseudohemorrhage."

On the other hand, Cox is disappointed that retroperitoneal hemorrhage rates weren't reported in RIVAL. "I'm astounded that such a wonderful study didn't report that. He cited recent BlueCross/BlueShield data from Michigan showing that in over 10 000 patients, the rate of retroperitoneal hemorrhage was 0.4% and a predictor of in-hospital and out-of-hospital death. Patients at risk for this injury are good candidates for the radial-access approach, Cox argues. "That's the target for radials, and that's why I want to be the best radial operator that I can be. To prevent that in my patients."

Many unknowns remain

Cox argued that the ACUITY trial showed that although the transradial approach results in fewer access-site bleeds than the transfemoral approach, this difference disappeared in patients appropriately treated with bivalirudin. He also acknowledged that patients generally prefer the transradial approach but argued that transfemoral patients treated with an access-site closure device are usually able to walk within a few hours anyway.

Mann argued that the cost of the femoral closure devices needs to be accounted for in the comparison of the two access methods. "A wise man said sooner or later we're going to be responsible for the costs we generate in the cath lab."

At the end of the debate, the chair of the session on transradial PCI, Dr Sunil Rao (Duke University, Durham, NC), argued for a randomized trial comparing outcomes and costs of transradial PCI with transfemoral PCI with a closure device. He added that the companies that manufacture the closure devices could easily afford to fund such a study, while there is no comparable industry support for the transradial approach.

Cox is an advisor for Abbott Vascular and Boston Scientific. Mann receives grants or research report from Abbott and Boston Scientific. Rao is a consultant for Zoll, Terumo, and the Medicines Company and has grants from Ikaria and Abbott.

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