DIPRA: Distal Radial Access Safe, No Negative Impact on Hand Function vs Proximal Radial Access

Karim Al-Azizi, MD

Results of the DIPRA study provide evidence supporting the use of distal radial artery access for cardiac catheterization.

Presented at the Society for Cardiovascular Angiography and Interventions (SCAI) 2022 Scientific Sessions, results of the study demonstrate distal radial artery access was a safe strategy with a low complication rate, with no significant differences observed for change in hand function of the catheterization hand when compared to proximal artery access up to 30 days post-procedure.

“Recently, we’ve seen growing interest in the distal artery as a unique access for cardiac catheterization,” said lead investigator Karim Al-Azizi, MD, FSCAI, an interventional cardiologist at Baylor Scott and White Health at The Heart Hospital in Plano, Texas, in a statement. “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.”

Although proximal radial artery access is recommended within guidelines as the preferred method for cardiac catherization, concerns have grown around the potential risk for occlusion of the artery. As a result, interest in the prospect of distal radial artery access has grown. With this in mind, the Distal versus Proximal Radial Artery (DIPRA) trial was launched to assess the differences in procedural success rate and assessment of hand function post-cardiac catheterization.

Conducted at Baylor Scottand White Health, the trial enrolled 300 patients from March 2020-December 2021 who underwent randomization in a 1:1 ratio to undergo cardiac catheterization with distal radial artery access or proximal radial artery access. For inclusion in the study, a patient’s distal radial artery and proximal radial artery needed to be palpable and non-occlusive flow needed to be confirmed via ultrasound. Additionally, distal radial artery and proximal radial artery needed to be sizable to accommodate at least a 5fr sheath.

The primary outcome of interest for the trial, which was assessed using average Z-score methodology, was change in hand function from baseline at 30 days and 1 year. For the purpose of analysis, hand function was defined as a composite of the QuickDASH questionnaire, the hand grip test, and the thumb forefinger pinch test, with the latter 2 measured with hand and pinch grip dynamometers. Secondary outcomes of interest included access feasibility, radial artery patency, and rate of complications.

At the time of analysis, 251 of the 300 patients who underwent randomization had completed their 30-day follow-up, including 126 randomized to distal radial access and 125 randomized to proximal radial access. Investigators pointed out demographics and procedural characteristics, including sheath size used and type of procedure completed were balanced in both groups.

Similar rates of access site bleeding were observed winning the distal radial access arm (0%) and the proximal radial access arm (1.4%) (P=.25). Investigators pointed out 6 patients in the distal radial access arm failed success access and were converted to proximal radial access and a pair of patients randomized to proximal radial access failed successful access. Further analysis revealed radial artery occlusion occurred among 2 patients in the proximal radial access arm and none in the distal radial access arm.

When assessing hand function, investigators found there were no significant differences in the change of and function in the cauterization for the composite score. When assessing individual components of the endpoint, no significant differences were observed between the distal radial access arm and the proximal radial access arm for hand grip (-0 [IQR,-3 to 3.3] vs 0 [IQR, -2.7 to 3.8] kg; P=.29), pinch grip (-0.3 [IQR, -1.2 to 0.5] vs 0 [IQR, -0.9 to 0.9] kg; P=.051), and QuickDASH (0 [IQR, -4.6 to 2.3] vs 0 [IQR, -4.6 to 2.3] points; P=.81).

This study, “Distal versus Proximal Radial Artery Access for Cardiac Catheterization and Intervention: 30-day outcomes of The DIPRA study,” was presented at SCAI 2022.