Large Meta-analysis Supports Radial as Default Approach in All CAD Types

Regardless of the type of CAD being treated, a radial-first approach results in fewer deaths and complications compared with femoral PCI, a large meta-analysis indicates. 

“These findings support the use of the radial access as the default approach for patients undergoing coronary interventions,” write Giuseppe Ferrante, MD, PhD (Humanitas Clinical and Research Center, Rozzano, Italy), and colleagues. Their study was published online June 29, 2016, before print in JACC: Cardiovascular Interventions.

Although randomized trials of radial versus femoral have shown conflicting results, Ferrante et al conducted what they term a “quantitative appraisal” of the issue by culling data from 24 studies that enrolled 22,843 patients who were treated with PCI for either stable CAD, NSTE-ACS, or STEMI.

Compared with femoral access, use of a radial approach resulted in lower likelihood of all-cause mortality (OR 0.71, 95% CI 0.58 to 0.87) and MACE (OR 0.84; 95% CI 0.75-0.94) in the overall population. Radial also was associated with less major bleeding (OR 0.53; 95% CI 0.42-0.65) and fewer major vascular complications (OR 0.23; 95% 0.16-0.34).

Importantly, MI and stroke rates were similar regardless of access site.

When analyzed by presentation, patients with ACS were less likely to experience NACE with radial versus femoral PCI (OR 0.75; 95% 0.61-0.91). Similarly, consistent benefits of radial over femoral access were seen for all clinical endpoints across the three subgroups, and individual subgroup and trial comparisons showed:

• Greater benefit of radial access on reducing major bleeding in stable CAD patients compared with those with NSTE-ACS or STEMI 
• Trends towards higher benefit of radial with regard to NACE in STEMI versus NSTE-ACS  
• Improved outcomes among centers with high radial expertise when radial was chosen over femoral access 

Safe, but Not Always the Right Choice

In an accompanying editorial, John A. Bittl, MD (Munroe Regional Medical Center, Ocala, FL), says the meta-analysis “provides moderately strong evidence that transradial PCI is slightly safer than transfemoral PCI.” 

But he notes that the approach “is not ideal for every procedure or every practitioner,” including many senior interventional cardiologists who “have performed tens of thousands of transfemoral PCIs safely, and get frustrated during transradial PCI by the occasional aortic arch that directs catheters into the descending aorta.”

In comparison, Bittl contends, younger operators “may have a stronger prehensile feel for radial access than do older practitioners, but not every patient is a candidate for transradial PCI.” He further notes that while radial procedures in the United States “will continue to gradually replace transfemoral approaches as older practitioners retire,” the changeover might be more rapid if radial access were reimbursed at a higher rate than the transfemoral approach.

‘Complete Lack of a Downside’ to Radial

“Whenever a disruptive change is induced in an ecosystem, especially a medical ecosystem, which is inflexible by its inherent nature, we tend to disown the change,” said Samir B. Pancholy, MD (Commonwealth Health, Scranton, PA), in an interview with TCTMD. “When a femoral-only operator comes and tells me that he can do a femoral just as well as I can do a radial, I beg to differ. That’s not what the evidence-based literature indicates, and there is more literature comparing radial versus femoral than any other modality, technology, or procedure in the interventional cardiology space.”

Although trials such as RIVAL and MATRIX have suggested that radial probably is associated with lower mortality after PCI, the new meta-analysis, “shows that not only is the signal very unidirectional, but it’s fairly unequivocal that radial is superior,” said Pancholy, who was not involved in the study. “There is no question of the effect that choosing radial had on mortality.”

He added that the fact that a center’s radial volume was a major driver of improved mortality in the subanalyses should not be overlooked. “In the high-volume centers, all the important outcomes were significantly better with radial than with femoral,” he noted. “This is telling us about the importance of radial first because … if you choose to only do it once in a while, and only consider radial when there’s a problem with femoral access, you fall in the category of low volume. Maybe it’s equivalent to femoral, but it’s not better.”

Another important message is “the complete lack of a downside of doing radial access,” Pancholy noted. “In the majority of skill-based procedures in the medical field, inexperienced people are going to create patient harm much of the time. In all of the studies included in this meta-analysis there was no signal for an increase in harm even among the low-volume operators or institutions.”

In their paper, Ferrante and colleagues note that the mechanisms for why radial delivers such improved outcomes over femoral are poorly understood. Although most of the benefit is believed to derive from reductions in bleeding, Pancholy said he believes the truth is still out there.

“A very large randomized study is needed to understand the mechanisms at play. There’s no argument anymore that radial is better, but when we ask ourselves why does it save more lives, the answer is we don’t know,” he observed. “Reduced bleeding is a driver of the improvement, but there probably are other components as well.”

Disclosures:

• Ferrante and Bittl report no relevant conflicts of interest. 
• Pancholy reports serving as a consultant for Terumo Interventional Systems. 

Related Stories:

• Transradial PCI Shows Consistent Benefit in All ACS Patients: MATRIX Access
• Higher Volume and Proportion of Transradial Cases Linked with Lower Mortality
• Radial vs. Femoral Angioplasty: Still RIVALs