Abstract WP225: Changes in Hemoglobin Levels During Vascular Events in Moyamoya Arteriopathy

Abstract

Background: Anemia is a well-established risk factor for stroke in many populations. Recent data suggest that in patients with moyamoya arteriopathy (MMA), decrease in hemoglobin is associated with perioperative stroke. Evaluating the role of anemia in stroke pathogenesis outside of the perioperative period in MMA could aid in risk stratification and stroke prevention. Hypothesis: We hypothesized that patients with MMA have lower hemoglobin levels in the setting of vascular events compared to their pre-event baseline. Methods: In this retrospective self-controlled case series, we abstracted demographic and clinical data from patients < 40 years old with MMA cared for in our institution’s pediatric or young adult stroke clinics between 2003 and 2023. Laboratory data for each vascular event (stroke or TIA) were collected. The most recent laboratory data preceding events were also collected (baseline). Perioperative events (those occurring ≤7 days after revascularization) were excluded. Pre- and post-revascularization events were analyzed together and separately. Paired T-tests were used to compare baseline and vascular event hemoglobin values. Results: Eighty-nine (89) participants met inclusion criteria. There were 32 vascular events with corresponding baseline data available. There was no significant difference in hemoglobin between event and baseline values (11.2 v 11.3 g/dL, p = 0.87). However, among only pre-surgical events (n=20), hemoglobin was lower during events compared to baseline (10.4 v 11.5 g/dL, p=0.03). For events that occurred >7 days post-revascularization (n=12), hemoglobin was higher during events compared with baseline (12.6 v 10.9 g/dL, p=0.008). Conclusions: In our cohort of children and young adults with MMA, hemoglobin was lower than baseline during presurgical vascular events and higher than baseline during post-revascularization vascular events. Though further exploration with multivariate models is necessary, these preliminary data suggest that while anemia and dehydration may both increase the risk of stroke in MMA, the relative contributions of these stroke risk factors differ based on surgical status.