Background and purpose: RAO is caused by various etiologies and subsequent vascular events may be associated with underlying etiologies. Our aim is to investigate the etiologies of RAO, the occurrence of subsequent vascular events and their association in patients with RAO.
Methods: We analyzed data from 151 consecutive patients presenting with acute non-arteritic RAO between 2003 and 2013 in a single tertiary-care hospital. The primary outcome was the occurrence of a vascular event defined as stroke, myocardial infarction, and vascular death within 365 days of the RAO onset. The Kaplan-Meier survival analysis and Cox proportional hazard model were used to estimate the hazard ratio of the vascular events.
Results: Large artery atherosclerosis (LAA) was the etiology more frequently associated with of RAO (41.1%, 62/151). During the one year follow-up, ischemic stroke and vascular events occurred in 8.6% and 9.9% of patients, respectively. Ten vascular events occurred in RAO patients attributed to LAA and 4 occurred in undetermined etiology. RAO patients with LAA had a nearly four times higher risk of vascular events compared to those without LAA (hazard ratio 3.94, 95% confidence interval 1.21-12.81). More than a half of all events occurred within one month and over three fourths of ischemic strokes occurred ipsilateral to the RAO.
Conclusion: After occurrence of RAO, there is a high risk of a subsequent vascular event, particularly ipsilateral stroke, within one month. LAA is an independent factor for the occurrence of a subsequent vascular event. Management for the prevention of secondary vascular events is necessary in patients with RAO especially with LAA. Large clinical trials are needed to confirm these findings.