CARC8: Right versus Left Axillary Artery Access in Impella 5.5 Insertion

Background: The Impella 5.5® is commonly inserted via the axillary artery (AX) in patients with cardiogenic shock. Insertion of Impella through the left AX requires crossing the aortic arch, and possibly a divergent angle of insertion through the aortic valve. However, there is limited data on comparison of choice of laterality of access, both in terms of technicality of the procedure as well as outcomes on device support. Methods: We performed a single-center retrospective cohort analysis of patients who underwent Impella 5.5® implantation between December 2020 and November 2022 (N=28). Data including demographics and outcomes were stratified by laterality of AX access. Adverse events included stroke, ipsilateral upper extremity ischemia, bleeding related to vascular access, infection related to Impella use, and unplanned explant due to complications. Delivery time was defined as time from advancing the first wire to activation of the device. Results: Twenty patients had insertion via the right axillary artery and 8 patients had access through the left side. Average duration of support was comparable (right, 9.8 + 5.3 vs. left, 10.2 + 6.6 days, p=0.83). The median delivery time was lower through right side compared to left sided access (7.9 + 3.6 vs. 12.4 + 6.9 minutes, p=0.048). Overall survival to discharge was 64.3%, with a 21.4% mortality while on support, but there was no difference between groups. Explant rate was similar in both groups (right, 80% vs. left, 75%, p=0.77). Overall adverse event rate was 3.5%, with surgical evacuation of implantation site hematoma in 1 patient with left sided access. There was no difference between the rates of suction events, hemolysis, repositioning or removal required when comparing right versus left. Neither group had patients with stroke, arm ischemia, or infection. Conclusion: Overall, Impella 5.5 support via the AX demonstrated favorable outcomes regarding a low incidence of adverse events and stable support with a high explant rate. In our study, the choice of laterality of AX access for Impella insertion did not affect outcomes, with a similar safety profile. Access through the right AX may be preferable due to shorter delivery time in the absence of contraindications.