Introduction Posterior circulation strokes account for 20% of all ischemic strokes but are a disproportional cause of morbidity and mortality. New cardiac arrhythmias have been described after ischemic stroke, but it is unclear whether patients with a posterior circulation stroke are at higher risk of developing new arrhythmia. We therefore conducted two retrospective analyses to evaluate the association between stroke circulation and risk of new arrhythmia after stroke.

Methods We performed a retrospective analysis of prospectively collected claims data from the National Readmission Database (NRD) between 2012 and 2014. We included patients with a primary diagnosis of stroke during their admission and evaluated for all newly diagnosed arrhythmias either on admission or follow-up until the end of the calendar year. Validated ICD-9-CM codes were used to identify the qualifying event and outcome. We fitted unadjusted and adjusted Cox proportional hazards models to identify factors associated with new arrhythmias in patients with stroke. In a separate but similar analysis, we performed a retrospective chart review of all stroke hospitalizations at Harborview Medical Center between 2017 and 2022. We abstracted data on demographics, comorbidities, stroke characteristics, and hospital course. Unadjusted and adjusted logistic regression models were used to evaluate the association between these factors and risk of new arrhythmias.

Results In the NRD, we evaluated 409,668 patients who were admitted for a primary stroke (mean age 68.6 [14.4]; 208,942 [51.0%] female). Of these, 13,328 (3%) were diagnosed with a new arrhythmia on admission or follow-up. Patients with a new arrhythmia were more likely to be older (hazard ratio [HR] 1.02; 95% confidence interval [CI] 1.02–1.02; p<0.001), covered by Medicare/Medicare (HR 1.38; 95% CI 1.18–1.62; p<0.001), have longer hospital stays (HR 1.01; 95% CI 1.00–1.01; p<0.001), and be intubated while hospitalized (HR 1.76, 95% CI 1.47–2.12; p<0.001). There was no association between posterior circulation stroke and risk of new arrhythmia (HR 0.89; 95% CI 0.63–1.27; p=0.527). In our single-institutional chart review, we evaluated 1,234 patients who were treated for stroke (mean age 70.8 [14.1]; 505 [41.4%] female). Of these, 64 (5%) were diagnosed with a new arrhythmia on admission or follow-up. Older age (adjusted OR 1.02; 95% CI 1.00–1.04; p=0.048) and large vessel occlusion (adjusted OR 2.12; 95% CI 1.00–4.35; p=0.044) were the only factors associated with higher risk of developing a new arrhythmia in both unadjusted and adjusted analyses. NIHSS >20 was associated with higher risk in unadjusted analyses only (OR 2.14; 95% CI 1.04–4.59; p=0.042). There was no association between laterality (OR 1.45; 95% CI 0.84–2.56; p=0.189) or circulation of stroke (OR 1.19; 95% CI 0.60–2.25; p=0.604) and risk of new arrhythmia.

Conclusions Posterior circulation stroke was not associated with higher risk of new arrhythmia. Patients who are at higher risk and may benefit from close cardiac monitoring include those who are older, covered by public insurance, and have a large vessel occlusion.

Disclosures K. Vanent: None. K. Carroll: None. K. Prijoles: None. M. Levitt: None.