DIPRA Study’s 30-Day Findings Compare Distal and Proximal Radial Artery Access

May 19, 2022—The single-center DIPRA randomized controlled trial evaluated outcomes of hand function and effectiveness of conventional proximal radial artery (PRA) access compared to distal radial artery (DRA) access for cardiac catheterization.

According to the Society for Cardiovascular Angiography & Interventions (SCAI) press release, the study’s background is that current guidelines recommend PRA access for patients undergoing percutaneous intervention. However, a complication of PRA is radial artery occlusion, which can compromise the access of the artery for future coronary bypass surgery, dialysis, or other cardiovascular procedures.

DRA has the potential to preserve the radial access, but little is known of the potential detrimental effects on hand function due to the close proximity to the radial nerve, noted SCAI.

In the DIPRA study, 300 patients were randomized 1:1 to undergo cardiac catheterization through the DRA or PRA. The primary endpoint was a change in hand function from baseline at 30 days and 1 year. Hand function was a composite of the QuickDASH questionnaire, handgrip test, and pinch test. Secondary endpoints included access feasibility, radial artery patency, and complications.

The initial 30-day findings from DIPRA were presented as late-breaking clinical research at the SCAI 2022 scientific sessions held May 19-22 in Atlanta, Georgia. The investigators noted that data is being collected out to 1-year to evaluate the safety of DRA on hand function and they anticipate sharing results in 2023.

As reported in the SCAI press release, 251 patients completed the 30-day follow-up with 126 of these patients randomized to DRA and 125 to PRA. Both groups had similar rates of access site bleeding (DRA, 0% vs PRA, 1.4%). Radial artery occlusion occurred in two patients in the PRA versus none in the DRA.

There was no significant difference in the change of hand function in the catheterization hand, measured in the following:

• In handgrip (DRA -0, interquartile range [IQR] -3, 3.3] vs PRA 0 [IQR-2.7, 3.8] kg
• In pinch grip (DRA -0.3 [IQR-1.2, 0.5] vs PRA 0 [IQR -0.9, 0.9] kg)
• In QuickDASH (DRA 0 [IQR -4.6, 2.3] vs PRA 0 [IQR -4.6, 2.3] points).

There was no significant difference in the composite of hand function between PRA and DRA, concluded the investigators.

The lead author of the DIPRA study is Karim Al-Azizi, MD, an interventional cardiologist at Baylor Scott & White Health—The Heart Hospital in Plano, Texas.

“Recently, we’ve seen growing interest in the distal artery as a unique access for cardiac catheterization,” commented Dr. Al-Azizi in the SCAI press release. “This study serves as reassurance for physicians that should we choose distal radial access over proximal access, it is safe at 30 days and provides minimal risk to hand function.”