Association Between Hospital-Ascertained Atrial Fibrillation And Central Retinal Artery Occlusion: A Study Of 12 Million Patients
Jay Lusk1, Ailin Song2, Shakhthi Unnithan3, Hussein Al-Khalidi3, Jonathan Piccini4, Ying Xian5, Emily O'Brien6, Brian Mac Grory7
1Duke University School of Medicine and Fuqua School of Business, 2Duke University Department of Ophthalmology, 3Duke University Department of Biostatistics and Bioinformatics, 4Duke University Departments of Medicine and Population Health Sciences, 5University of Texas Southwestern Medical Center, 6Duke University Departments of Population Health Sciences and Neurology, 7Duke University Departments of Neurology and Ophthalmology
Objective:
To determine whether hospital-ascertained atrial fibrillation (AF) is associated with subsequent central retinal artery occlusion (CRAO).
Background:
Atrial fibrillation is a major risk factor for cerebral ischemic stroke. However, it is not known whether AF predicts the development of central retinal artery occlusion.
Design/Methods:
A retrospective cohort study was undertaken using data from the California Healthcare Cost and Utilization Project (HCUP) State Inpatient and State Emergency Department Datasets (SID/SEDDs). Patients 18 years and older discharged from non-federal hospitals between 2005 and 2011 who did not have a history of CRAO were analyzed. AF and CRAO were identified using validated ICD-9-CM diagnosis codes. Association between AF and CRAO was modeled using a Fine-Gray method with death as a competing risk with adjustment for age, biological sex, race, and vascular comorbidities.
Results:
A total of 12,181,778 patients were included, 806,397 with AF and 11,375,381 without AF. In total, 309 patients had CRAO. In an unadjusted analysis, there was a higher risk of CRAO in patients with versus without AF (HR 2.24 (95% CI: 1.51 to 3.32)). After adjustment for pre-specified covariates, there appeared to be a lower hazard of CRAO in patients with AF (aHR 0.61 (95% CI: 0.45 to 0.98)). Further analyses including cerebral ischemic stroke (aHR 1.16 (95% CI: 1.14 to 1.18)) and specifically embolic stroke (aHR 4.29 (95% CI 4.10-4.48)) as positive controls argued against overadjustment bias. We present sensitivity analyses including CRAO identified in any position of the ICD list, using different ascertainment windows for AF and using broader categories of retinal ischemia.
Conclusions:
The incidence of CRAO was higher in patients with AF than those without AF, but the hazard of CRAO was not higher for patients with AF after adjustment for measured covariates. Endpoint and exposure ascertainment may have been limited by inclusion only of inpatient and emergency department encounters.