Abstract 52: Clinical Impairment in Patients Followed With or Without Interventional Therapy in a Randomized Trial of Unruptured Brain Avms (aruba)

Background and Purpose: A Randomized trial of Unruptured Brain Arteriovenous malformations (ARUBA) compared outcome after interventional treatment of unbled brain AVMs with medical management. Follow-up data to assess pre-specified functional impairment after primary outcome events by treatment group and exploratory analyses by Spetzler-Martin grade are presented. Methods: We examined functional impairment using the modified Rankin scale score (mRS ≥2) at the time of primary outcome (death or stroke) by treatment group, and an exploratory analysis with these outcomes by Spetzler-Martin Grade. Analyses were performed both by intention to treat (as randomized) and as treated. Results: After a median of 42 months of follow-up, the median post-primary outcome event mRS for those ‘ as randomized ’ to medical management (MM) was 2 (IQR: 1,4) versus 3 (IQR: 1,5) in the interventional therapy (IT) arm. Values for those ‘ as treated’ , were 1 (IQR: 1,5) versus 4 (IQR: 2,5). The risk of functional impairment, as measured by an mRS ≥2 after a primary outcome event, was significantly lower for patients ‘ as randomized’ to MM (8/110, 7%) compared to IT (27/116, 23%) (HR 0.26, 95%CI 0.12, 0.57), and even lower for those ‘as treated’ (4/122, 3% vs 31/104, 30%; HR 0.09, 95% CI 0.03,0.27). Spetzler-Martin Grade and primary outcome events were not associated in the medical arm (p=0.80) but were so with increasing grades in the interventional arm (p=0.0002). Conclusion: In ARUBA, a death or stroke with a significant increase in functional impairment was more common for patients undergoing preventive intervention compared to those randomized to medical management.