LAUSR

Background: Takayasu’s Arteritis (TAK) is a rare granulomatous inflammation of the large vessels. Its incidence has been reported to be 2-3 cases per million people in the United States. To our knowledge an inpatient nationwide study of TAK in the United States has not been conducted to date. The aim was to evaluate the demographic characteristics, reason for admission, procedures, mortality and resource utilization of patients with TAK using a national database. Objectives: The primary goal was to estimate the national inpatient prevalence of admissions involving patients with TAK. Secondary outcomes were top reasons for admission, mortality, morbidity, resource utilization, length of hospital stay (LOS), and total hospitalization charges and costs, adjusted for inflation using the Consumer-Price Index. Methods: All patients with a principal ICD9 diagnosis code for TAK were included using the NIS 2013 and 2014, the largest publically available inpatient database in the US. Controls were 1:1 matched using a propensity score including age, gender, and Charlson Comorbidity Index (CCI). Multivariate logistic regression models were used to adjust for race, sex, patient zip code, income, CCI, hospital region, location, size and teaching status. Results: Of a total of 2,840 hospital admissions for patients with TAK, 2,680 were propensity-matched to admissions without TAK and included in the study. Mean age was 49 years, 81% were female. The inpatient prevalence of TAK was 4.6/100,000 admissions. After adjusting for confounders, patients with TAK had propensity-matched mortality odds of 1.44 (p=0.43) when compared to patients without TAK. The top reasons for admission were large vessel vasculitis, sepsis secondary to pneumonia and urinary tract infection, carotid artery stenosis/occlusion, and arthralgias. For secondary outcomes, patients with TAK displayed increased odds of stroke, aortic aneurysm, peripheral vascular disease and aortic valvulopathy when compared to patients without TAK. When CCI was evaluated it was noted that all the patients had an index lower than 4 and the great majority lower than 2 which could be related to the young age of this population. Despite the low CCI, these patients had 7.35 days of in-hospital stay which represented 2.1 days more when compared to non-TAK patients. For resource utilization, patients with TAK displayed higher odds of peripheral vascular intervention and arteriography when compared to patients without TAK. Patients with TAK displayed significantly higher adjusted total hospital costs, charges and LOS compared to patients without TAK. Conclusion: The inpatient prevalence was higher than suspected and could be related to the severity of the disease and complications associated with TAK. TAK was associated with an increased risk of stroke, aortic aneurysm, peripheral vascular disease and vascular interventions, but no increase mortality in this group of patients. The costs associated with hospitalization were substantial. References: [1] Watanabe Y, Miyata T, Tanemoto K. Current Clinical Features of New Patients With Takayasu Arteritis Observed From Cross-Country Research in Japan: Age and Sex Specificity. Circulation. 2015;132(18):1701-9. [2] Schmidt J, Kermani TA, Bacani AK, Crowson CS, Cooper LT, Matteson EL, et al. Diagnostic features, treatment, and outcomes of Takayasu arteritis in a US cohort of 126 patients. Mayo Clinic proceedings.2013;88(8):822-30. Disclosure of Interests: None declared