Abstract TP024: Observations from Hotline Usage in an Acute Stroke Trial: Characteristics of Complex Cases

Background: The Multi-arm Optimization of Stroke Thrombolysis (MOST) trial was a single-blind, phase 3, randomized trial evaluating whether adjunctive treatment with argatroban or eptifibatide alongside IV thrombolysis improved outcomes. Given the trial’s time-sensitive nature, a 24/7 hotline was established to support site personnel during enrollment. Our objective was to describe the characteristics of enrolled patients for whom a call occurred and evaluate whether hotline use was associated with protocol deviations and markers of clinical severity. Methods: All calls were recorded between June 2022 and July 2023, when the trial closed. During this period, 167 subjects were enrolled. Calls were linked to enrolled patients where applicable. Enrolled patients were categorized based on whether a related hotline call occurred. We calculated frequencies and proportions with 95% confidence intervals (CIs) for categorical variables and medians with interquartile ranges (IQRs) for continuous variables. Results: Of 167 subjects, 70 (41.9%) had at least one related hotline call. Patient demographics and characteristics were generally similar between call and no-call groups (Table 1). Protocol deviations occurred in 74.3% of the hotline group (95%CI: 62.2, 83.7) and 24.7% (95%CI: 16.8, 34.7) of the no-call group. The most frequent eligibility issue was exceeding the 75-minute study drug window (Table 2). Of the 157 who received study drug, median time to study drug was higher in the hotline group (173 min, IQR: 145-198 vs. 151 min, IQR: 131-174). The median utility-weighted modified Rankin Scale was similar between groups (7.6, IQR: 3.3-9.1 vs. 7.6, IQR: 6.5-9.1). Symptomatic intracranial hemorrhage (sICH) (8.6%, 95%CI: 3.5, 18.4 vs. 1.0%, 95%CI: 0.1, 6.4) and all-cause mortality (20.0%, 95%CI: 11.7, 31.6 vs. 8.2%, 95%CI: 3.9, 16.1) were higher in the call group, although neither were significant. Conclusion: In MOST, protocol deviations occurred more frequently for patients in the hotline call group, particularly regarding the 75-minute drug administration window, underscoring the difficulty of adhering to strict trial protocol timelines in real-world settings. Higher sICH and mortality in the hotline group likely reflect the greater complexity of cases for which support was sought. These findings highlight the value of 24/7 expert support in acute care trials to guide decision-making and uphold protocol integrity under pressure.