Distal Radial PCI Safety for the Hand Holds Up Longer Term

PHOENIX — Introducing the percutaneous coronary intervention (PCI) catheter through the anatomical snuffbox on the wrist remained as safe at 1 year for hand function as the usual radial access route, longer-term results from the DIPRA trial showed.

All three measures of function — hand grip, pinch grip, and patient-reported performance in daily life — showed similar results between PCI access routes at 1 year, reported Karim Al-Azizi, MD, of Baylor Scott & White Health in Frisco, Texas, at the Society for Cardiovascular Angiography and Interventions (SCAI) meeting here.

The composite hand function z-score declined by 0.07 points in the distal radial access group and by 0.03 in the proximal radial access group compared with baseline, which was not a significant difference (P=0.59).

The findings largely mirrored the 30-day results reported at SCAI the year prior, but without the trend for a differential change in pinch grip strength as a component of the hand function composite endpoint seen at the early point (albeit also seen in the uncatheterized hand). At 1 year, pinch grip z-score was -0.09 in the distal radial artery access group compared with baseline and -0.02 in the proximal radial artery access group (P=0.66).

While the trial was underpowered for radial artery occlusion, no cases either distal or proximal, were seen at 1 year after distal radial artery access PCI. In the proximal radial artery group, there were two cases of distal occlusion and one of proximal occlusion (2% and 1%, respectively, P=0.48).

Based on prior meta-analysis of several registries and short-term outcome studies, “there has been a strong signal about reduction in radial artery inclusion rates in distal cohorts versus proximal, though not shown here because we’re not really powered for it,” Al-Azizi said.

Another potential advantage is preserving the radial artery for future use in arteriovenous grafts for dialysis or for coronary artery bypass graft use, he added.

“We are pushing radial in general, but [distal radial] is still something that we can keep in the toolbox and perhaps actually there is an argument for it in certain patients over proximal,” he said.

There has been a shift in the U.S. toward radial catheterization, now accounting for some 70% of PCI access according to the NCDR registry, “which is a huge change compared to about 5 or 10 years ago,” noted session moderator Prashant Kaul, MD, of the Piedmont Heart Institute in Atlanta. “So congratulations to everyone, I guess, for that.”

While his informal survey of the room showed a similar proportion of radial-first operators, none indicated a predominantly distal radial approach.

Al-Azizi acknowledged the learning curve for operators but noted that several operators came into the study who didn’t do distal radial access initially. “It is being adopted nicely; our fellows are enthused about it.”

More importantly, he said, “Patients love it. They are less likely to have hematoma.”

Indeed, patient comfort level might be what moves the needle, “whether it’s faster movement, less pain, less discomfort, whether acutely, subacutely or even chronically,” suggested Gagan Singh, MD, of the UC Davis Medical Center in Sacramento, California.

Even with a radial occlusion, “they don’t really care as long as it’s not bothering them,” he said. “They may not care about the downstream effects, but discomfort is a big deal.”

The DIPRA trial included 300 randomized patients with a mean age of 66.6, among whom 32% had diabetes mellitus, 77% had hypertension, and 19% had prior PCI. Radial artery catheterization in the prior year was an exclusion criterion. Patients could decide whether their dominant or non-dominant hand was used for access. The primary composite endpoint included hand grip and thumb-to-forefinger pinch grip strength, as measured before and after the procedure with a dynamometer, as well as the QuickDASH survey, typically used in occupational therapy for self-reporting hand function in daily use scenarios, like opening a jar.

Session panelist Samir B. Pancholy, MD, of the Wright Center for Graduate Medical Education in Scranton, Pennsylvania, called the 216 patients who completed assessment at 1 year out of the 300 randomized patients “a fair loss to follow-up” of about 20% that “could very significantly affect outcomes.”

Al-Azizi responded that “it was reassuring that on the long term, despite the loss to follow-up, you get the same signal.”