Abstract WP130: Unruptured Intracranial Aneurysm Treatment Score Fails for at Risk Patients Over 58 Years Old

Abstract

Introduction: The Unruptured Intracranial Aneurysm Treatment Score (UIATS) weighs treatment versus observation risk, while the PHASES score estimates rupture risk. Certain clinical and radiographic features overlap between them whereas other features diverge. Thus management decisions may rely on conflicting information. Objective: We sought to determine the UIATS for known aneurysmal subarachnoid hemorrhage (aSAH) patients, as if the aneurysms been detected prior to rupture, and to correlate this with their PHASES scores. Methods: UIATS and PHASES scores were calculated for consecutive aSAH patients admitted to a regional stroke center between 1/2014 and 8/2018. A UIAT differential score was derived by subtracting the ‘observation’ from the ‘treatment’ score (a higher score favors treatment). Pro-treatment UIATS rates were calculated for the whole group and after excluding patients with non definitive scores of -3 to 3. These rates were also calculated for age-quartiles (<44, 45-58, 59-66, and >/=67 years). The relationship of age and PHASES scores with UIATS was assessed using logistic regression. Results: Of 130 total patients, 121 (mean age 55 +/-15 years) had complete data, with median PHASES score of 5, concordant with their ultimate aSAH. Conversely, their median UIATS score was -1, and only in 54 (45%) did the score show balance (0) or favor treatment. Excluding those with UIATS -3 to 3, the number dropped to 18 (15%). Each unit increase in PHASES score was associated with 23% higher likelihood of pro-treatment UIATS (OR: 1.23, 95% CI: 1.05-1.44, p=0.009) indicating a degree of harmony. In contrast, although age>/=70 increases PHASES score, the odds of UIATS favoring treatment decreased by 5% with each year increase [OR: 0.95, 95% CI: 0.92-0.98, p=0.002]. When the four quartiles were analyzed, as age rose >58 years, the likelihood of pro-treatment UIATS fell (45-58 years, 63%; 59-66 years, 32%; >/=67 years, 0%). Results were comparable when analysis was repeated after excluding cases with UIATS - 3 -to 3. Discussion: UIATS and PHASES scores help guide management discussions, but clinicians should assume caution with those>58 years, as UIATS is more likely to fail these patients, who may still be at greater natural history risk of aneurysmal rupture.