Radial Superior to Femoral Access in Patients With Prior CABG

For patients with a history of CABG surgery in need of a diagnostic catheterization and/or PCI, radial artery procedures are associated with a significantly lower risk of death, bleeding, and vascular complications when compared with procedures performed with femoral access, according to an observational study.

Experts say the new report provides yet more evidence for the “radial-first” approach advocated by the American Heart Association, and hope it will encourage more US operators to adopt radial access for patients with surgical grafts. This analysis confirms such a strategy is used in fewer than one in five patients in this subset.

“At our center, we’re 96% radial access,” senior researcher Sunil Rao, MD (Duke University Medical Center, Durham, NC), told TCTMD. “We do everybody with radial access if we can, regardless of whether they’ve had bypass surgery. We’ve gotten pretty good at setting up the patient and making it comfortable for the operator to use the left side. As you can see in this study, if the overall rate of radial access is about 50% in the US, only 19% of patients with a prior bypass are getting radial access. It still seems to be a barrier to some operators.”

Europe, Asia, and Canada have widely adopted the radial approach, and the overall percentage of cases done transradially in the United States has increased in the last decade. However, as David Fischman, MD (Thomas Jefferson University Hospital, Philadelphia, PA), notes in an accompanying editorial, “there still remains a large population of PCIs where the radial artery is not used for access, [and] specifically this includes the patient with prior coronary artery bypass surgery.”

From a technical standpoint, it can be a little more challenging to use the radial artery in patients with prior CABG surgery, and as such, operators may default to femoral access because they feel more comfortable, Fischman noted to TCTMD.  

“Many individuals do radial cases via the right radial artery,” he said. “They’re accustomed to working on that side of the patient. Some will do the left radial—I do the majority of mine with the left radial artery—but some think it’s more awkward to be on that side. The technical challenge is that if you’re going from the right side, and the patient has an internal mammary graft, crossing over from the right side to the left to get to the mammary is difficult. You really have to go on the left side if you want to get that easily.”

Rao noted that use of the left internal mammary artery (LIMA) for grafting to the LAD is a quality metric for CABG surgery, and that use of the LIMA can make a right-side transradial procedure trickier. “Surgeons really use that artery quite a bit, and it’s easier to get a picture of that bypass graft using the left radial artery rather than right,” he said. “If you’re coming from the right radial artery, your catheter has to do a little bit of gymnastics to get up into the left shoulder. If you’re coming from the left wrist, the left shoulder is a straight shot and you can get the LIMA very easily.”

The new study was published online March 31, 2021, ahead of print in JACC: Cardiovascular Interventions.

No Harm to Patient or Operator

Two small studies have specifically sought to evaluate radial access in patients with prior CABG surgery, with mixed results. In the RADIAL-CABG study, which looked at radial versus femoral access for diagnostic angiography, the radial approach was associated with longer procedures, greater use of contrast, and increased radiation exposure. On the other hand, the L-RECORD study showed the radial approach didn’t negatively affect procedure or fluoroscopy times or lead to more radiation or higher contrast volumes.

Clinical trials such as RIVAL, RIFLE-STEACS, and MATRIX, all of which provided solid evidence for improved patient outcomes with radial access, have largely excluded patients with a history of CABG from those trials.

In this study, the researchers analyzed 1,279,058 index procedures in patients with a history of CABG surgery performed between 2009 and 2018 at 1,173 sites and included in the National Cardiovascular Data Registry (NCDR) CathPCI Registry. Of these, 35.3% of the procedures involved a diagnostic cardiac catheterization plus PCI, 60.9% involved a diagnostic cath alone, and 3.8% involved a PCI alone. In 2009, just 1.4% of the procedures were performed via the radial artery. By 2018, 18.7% of cases were done with radial access.   

Overall, women were less likely than men to be treated with the radial approach, as were Black patients, whereas those with a history of PCI and PAD were more likely to be treated via the wrist. Patients treated at hospitals with the highest average annual PCI volume (≥ 2,000 cases per year) were more likely to undergo radial-access procedures, as were those treated at a teaching hospital. Not surprisingly, operators who performed more of their overall procedures via the radial route were more likely to use radial access when treating patients with a prior CABG.

After inverse propensity weighting, the radial approach was associated with a lower risk of mortality (OR 0.83; 95% CI 0.75-0.91), a lower risk of bleeding (OR 0.57; 95% CI 0.51-0.63), and deceased vascular complications (OR 0.38; 95% CI 0.30-0.47) compared with transfemoral procedures. The radial approach was also associated with greater procedural success, less bleeding at 72 hours, and lower contrast volume, although fluoroscopy times were slightly longer (12.1 vs 9.4 minutes).

Given the study’s observational nature, Rao was cautious interpreting the outcomes data, but said the results line up with prior randomized trials. The reduction in bleeding and vascular complications have been shown in the major trials, and these findings, including the procedural outcomes, should provide reassurances for operators opting for the radial approach in patients with prior CABG.

“If you have someone who is proficient with radial access, they are not going to be putting themselves or the patient at risk by using radial access,” said Rao.  

In his editorial, Fischman says the study raises awareness about the need for further targeted education, homing in specifically on centers where radial access isn’t performed as frequently, such as lower-volume centers and nonteaching hospitals. “This needs to be adopted throughout,” Fischman told TCTMD. “Sometimes operators want to get in and get out as quickly as possible, and they think going through the radial artery is going to take more time. It really doesn’t. It’s about learning how to do it, feeling comfortable, and to keep pushing through.”