Examining the Association Between Hospital-Documented Atrial Fibrillation and Central Retinal Artery Occlusion.

Background: Carotid stenosis is thought to be the primary risk factor for central retinal artery occlusion (CRAO); however, it is not known whether atrial fibrillation (AF), a cardiac arrhythmia that underlies over 25% of cerebral ischemic strokes, predisposes patients to CRAO. Methods: A retrospective, observational, cohort study was performed using data from the State Inpatient Databases and State Emergency Department Databases from New York (2006-2015), California (2003-2011), and Florida (2005-2015) to determine the association between AF and CRAO. The primary exposure was hospital-documented AF. The primary endpoint was hospital-documented CRAO, defined as having an ICD-9-CM code 362.31 in the primary diagnosis position. Cause-specific hazard models were used to model CRAO-free survival among patients according to hospital-documented AF status. Results: Of 39,834,885 patients included in the study, 2,723,842 (median age: 72.7 years, 48.5% female) had AF documented during the exposure window. Patients with AF were older, more likely to be of non-Hispanic White race/ethnicity and had a higher burden of cardiovascular comorbidities compared to patients without AF. The cumulative incidence of CRAO was 7.09 per 100,000 at risk in those with AF and 2.34 per 100,000 at risk in those without AF over the study period. Before adjustment, AF was associated with higher risk of CRAO (HR 2.55, 95% CI 2.15-3.03). However, after adjustment for demographics, state, and cardiovascular comorbidities, there was an inverse association between AF and risk of CRAO (aHR 0.72, 95% CI 0.60-0.87). These findings were robust in our pre-specified sensitivity analyses. By contrast, positive control outcomes of embolic and ischemic stroke showed an expected strong relationship between AF and risk of stroke. Conclusions: We found an inverse association between AF and CRAO in a large, representative study of hospitalized patients; however, this cohort did not ascertain AF or CRAO occurring outside of hospital or emergency department settings.