Abstract P566: Identifying Sex-Specific Differences in the Carotid Revascularization Literature: Findings From a Scoping Review

Background and Purpose: No systematic review of the literature has dedicated itself to looking at the management of symptomatic carotid stenosis in women. In this scoping review, we aimed to identify all randomized controlled trials (RCTs) that reported sex-specific outcomes for patients who underwent carotid revascularization, and determine whether sufficient information is reported within these studies to assess women’s short and long-term outcomes.

Methods: We systematically searched Medline, Embase, Pubmed, and Cochrane libraries for RCTs published between 1991 and 2020 that included women and compared either endarterectomy with stenting, or any revascularization (endarterectomy or stenting) with medical therapy in patients with symptomatic high grade (greater than 50%) carotid stenosis.

Results: From 1,537 references examined, 27 eligible studies were identified. Sex-specific outcomes were reported in 13 studies. Baseline patient characteristics of enrolled women were reported in 2 of those 13 studies. Common outcomes reported included stroke and death, however there was significant heterogeneity in the reporting of both periprocedural and long-term outcomes. Sex-specific differences relating to the degree of stenosis and time from index event to treatment were limited to studies comparing endarterectomy to medical therapy. Adverse events were not reported by sex.

Conclusions: Half of the previously published RCTs and systematic reviews report sex-specific outcomes. Detailed analysis on the benefits of carotid artery intervention for women with symptomatic stenosis is limited . Further analysis with individual patient data and a network meta-analysis is the necessary next step to better assess the treatment effects of carotid management in women.

Abstract WP108: What is Equipoise? Stroke Researchers and IRB Chairs Respond

Background: The concept of “equipoise” is often cited as a prerequisite to the conduct of ethical randomized clinical trials (RCTs). However, significant difficulties persist in determining when it exists around a specific clinical question. This issue has arisen around recent stroke RCTs such as ESCAPE and SWIFT DIRECT. We sought to capture how stroke research principal investigators (PIs) and institutional review board (IRB) chairs understand the concept of equipoise.

Methods: We invited stroke PIs and IRB chairs to complete a telephone interview consisting of 9 semi-structured questions surrounding equipoise and the ethics of RCTs. Interviewees provided written informed consent and results remained anonymous. The study was approved by our local IRB. Interviews were recorded and transcribed. Each interview was then analyzed for relevance to the concept of equipoise, with relevant sections coded and organized into themes.

Results: We invited 59 PIs and 84 IRB chairs, with 13 PIs and 15 IRB chairs completing the standardized interview. Respondents defined equipoise in 5 different ways, with the most common definition being uncertainty based on any of individual opinion, group opinion, evidence, lack of evidence, regional variation, or trial design. PIs sought to determine equipoise through appeals to the literature, preliminary clinical data, surveys of expert opinion, and known disagreement. IRB chairs were more dependent upon expert opinion, including that of trial PIs themselves, and were more concerned with patient protections and specifics of study design. All (100%) PIs and 77% of IRB chairs felt that the concept was helpful, though 80% of both groups also found it to be problematic.

Conclusion: Stroke PIs and IRB chairs differ in their understanding of how equipoise is defined and operationalized, which may directly impact the design and approval of current and future stroke trials.