Abstract TP171: Liver Cirrhosis is Associated With an Increased Risk of Aneurysmal Subarachnoid Hemorrhage

Abstract

Introduction: Cirrhosis has been associated with non-traumatic subarachnoid hemorrhage (SAH). Additionally, cirrhosis appears to contribute to the development of pulmonary vascular abnormalities. We therefore sought to investigate whether cirrhosis is associated specifically with aneurysmal SAH. Methods: We performed a retrospective cohort study using 2009-2015 inpatient and outpatient claims data from a 5% sample of Medicare beneficiaries ≥66 years of age. Our exposure was cirrhosis as defined by a previously validated algorithm using inpatient and outpatient ICD-9- CM diagnosis codes. The outcome of aneurysmal SAH was identified using a validated approach requiring an inpatient ICD-9-CM diagnosis code for non-traumatic subarachnoid hemorrhage, without concomitant diagnosis codes for trauma or rehabilitation. Additionally, to further ensure we were identifying aneurysmal SAH, we required the presence of an ICD-9-CM procedure code reflecting endovascular or surgical treatment of a cerebral aneurysm during the same hospitalization. Patients were censored at the time of death or end of Medicare coverage or on September 30, 2015. We used survival statistics to calculate incidence rates and Cox proportional hazards models to evaluate the association between cirrhosis and aneurysmal SAH after adjustment for demographics, established SAH risk factors, and Charlson comorbidities. Results: We identified 10,658 (0.6%) patients with cirrhosis from among the 1,778,604 beneficiaries in our sample. The mean age of patients with cirrhosis was 73.2 (±6.5) years, and 48% were female. Over a mean of 4.7 (±2.1) years of follow-up, 4,272 patients were hospitalized with aneurysmal SAH. The annual incidence of aneurysmal SAH in patients with cirrhosis was 0.11% (95% confidence interval [CI], 0.08-0.17%) compared to 0.05% (95% CI, 0.05-0.05%) in patients without cirrhosis. After adjustment for demographics, risk factors, and comorbidities, cirrhosis was independently associated with an increased risk of aneurysmal SAH (hazard ratio, 2.3; 95% CI, 1.5-3.4). Conclusions: We found that cirrhosis was associated with aneurysmal SAH among Medicare beneficiaries. Liver cirrhosis may be an independent risk factor for aneurysmal SAH.