Abstract WP254: Predictors of Atrial Fibrillation Detection by Mobile Cardiac Output Telemetry After Hospital Discharge for Acute Ischemic Stroke

Abstract

Background: Patients with cryptogenic stroke without atrial fibrillation (AF) detected in the hospital often undergo 30-day mobile cardiac outpatient telemetry (MCOT) to increase the AF detection rate. We sought to determine the clinical and transthoracic echocardiogram (TTE) characteristics associated with AF detection by MCOT. Methods: We analyzed a cohort of admissions from 2005 to 2016 with an acute ischemic stroke diagnosis, an inpatient TTE, and an MCOT performed upon discharge. Each admission was treated as a unique observation. Cases with subsequent AF vs. no AF on MCOT were compared by Chi-squared tests if variables were categorical and t-tests if continuous. A multivariable stepwise logistic regression model was created to determine the predictors of AF detection as a function of variables which were significant in univariate analysis and not significantly collinear. Results: Of the 4,880 inpatient hospitalizations for acute ischemic stroke with an TTE performed during admission, there were 283 cases which underwent MCOT (10.4 cases/year in 2005-2014, 90 cases/year in 2015-2016). There were 23 (8.10%) cases of AF on MCOT, and they were more likely to be older, white, admitted earlier during the study, and have larger left atrial anterior-posterior and medial-lateral dimensions (Table). A multivariable model demonstrated that age greater than the median of 66 yr (OR 3.25, 1.21-8.74) and left atrial anterior-posterior dimension greater than the median of 40cm (OR 5.86, 2.38-14. 43) were strong predictors of AF detection by MCOT (c-statistic 0.78). Conclusions: We observed low rates of AF on 30-day MCOT post-discharge. Left atrial anatomic dimension is predictive of a higher rate of early AF detection after adjusting for age. This TTE feature, coupled with clinical information, may improve patient selection for MCOTs and potentially avoid the need for more expensive implantable loop monitors in those for whom MOCT does not yield an answer.