Importance: Data regarding upper extremity midline catheter (MC)-related thrombosis (CRT) are sparse, with some evidence indicating that MCs have a high rate of CRT.
Objective: To compare 2 MCs with differing antithrombogenic mechanisms for this outcome.
Design, setting, and participants: In this parallel, 2-arm randomized clinical trial, 496 adult patients hospitalized at a tertiary care suburban academic medical center who received an MC were assessed for eligibility between January 1, 2019, and October 31, 2020, and 212 were randomized.
Interventions: Inpatients were randomized to receive a 4F antithrombotic MC (MC-AT) or a 4.5F antithrombotic and antimicrobial MC (MC-AT-AM).
Main outcomes and measures: The primary outcome was symptomatic midline CRT inclusive of deep vein thrombosis or superficial venous thrombophlebitis within 30 days after insertion. Secondary outcomes included catheter-associated bloodstream infection and catheter failure.
Results: A total of 191 patients (mean [SD] age, 60.2 [16.7] years; 114 [59.7%] female) were included in the final analysis: 94 patients in the MC-AT group and 97 in the MC-AT-AM group. Symptomatic midline CRT occurred in 7 patients (7.5%) in the MC-AT group and 11 (11.3%) in the MC-AT-AM group (P = .46). Deep vein thrombosis occurred in 5 patients (5.3%) in the MC-AT group and 5 patients (5.2%) in the MC-AT-AM group (P > .99). Pulmonary embolism occurred in 1 patient in the MC-AT group. No catheter-associated bloodstream infection occurred in either group. Premature catheter failure occurred in 22 patients (23.4%) in the MC-AT group and 20 (20.6%) in the MC-AT-AM group (P = .64). In Cox proportional hazards regression analysis, no statistically significant difference was found between groups for the risk of catheter failure (hazard ratio, 1.27; 95% CI, 0.67-2.43; P = .46).
Conclusions and relevance: No difference was found in thrombosis in MCs with 2 distinct antithrombogenic mechanisms; however, the risk of CRT in both groups was high. Practitioners should strongly consider the safety risks associated with MCs when determining the appropriate vascular access device.
Trial registration: ClinicalTrials.gov Identifier: NCT03725293.