Abstract T P157: The Effect of Paroxysmal Atrial Fibrillation on Stroke Outcomes Among Ischemic Stroke/TIA Patients: An Eight Year Cohort Study

Abstract

Background: Paroxysmal atrial fibrillation (PAF) is more prevalent than chronic AF in the general population. It may also be more prevalent in ischemic/TIA patients. It is difficult to diagnose PAF prior to event and most studies focus on chronic AF (CAF). In this study we evaluate the effect of PAF on stroke outcomes and highlight the need to focus on this treatable condition to ensure appropriate care. Methods: • The study population included ischemic/TIA cases with AF status known from July, 2006-July, 2014 (n=2951). AF status (n=573) was classified as paroxysmal (31.4%) or chronic (68.6%). o PAF was diagnosed with telemetry during hospitalization. • Outcomes included discharge disposition (alive/expired) and neurological impairment at discharge, quantified using the National Institutes of Health Stroke Scale (NIHSS). CHADS2 score was evaluated as a continuous variable. • Patient demographics and co-morbidities including diabetes, hypertension, smoking and dyslipidemia were considered as confounders in logistic regression. • Analysis was done using R-based statistical tools. Bi-variate analysis included t-tests for continuous variables and chi-square tests for categorical variables. Multivariable analysis was done using logistic regression. Results were determined to be statistically significant within a 95% confidence interval. Results: • PAF patients were more likely to be female (61.3%) than CAF (56.7%), although not significantly more likely, p=0.38. PAF patients were mean age of 76 (± 12.4) years. • PAF patients were two times as likely as non-AF patients and three times as likely CAF patients to expire (R.R. 2.2, 95% C.I. 1.17-10.9; R.R. 3.1, 95% C.I. 0.55-17.97). • There were no significant differences in recurrent stroke rate between PAF and CAF patients or PAF patients and non-AF patients. • Admission NIHSS and CHADS2 for PAF patients were higher than for non-AF patients (p<0.0001 for both). There were no significant differences between PAF and CAF patients. Conclusion: • PAF patients had a significantly higher mortality rates compared to CAF patients, despite no significant differences in CHADS2 or admissions NIHSS. • Careful evaluation is important for PAF patients since they are higher risk of poor outcomes.