Predictors of Atrial Fibrillation in Patients With Stroke Attributed to Large- or Small-Vessel Disease

Abstract

ImportanceThe Stroke of Known Cause and Underlying Atrial Fibrillation (STROKE AF) trial found that approximately 1 in 8 patients with recent ischemic stroke attributed to large- or small-vessel disease had poststroke atrial fibrillation (AF) detected by an insertable cardiac monitor (ICM) at 12 months. Identifying predictors of AF could be useful when considering an ICM in routine poststroke clinical care.ObjectiveTo determine the association between commonly assessed risk factors and poststroke detection of new AF in the STROKE AF cohort monitored by ICM.Design, Setting, and ParticipantsThis was a prespecified analysis of a randomized (1:1) clinical trial that enrolled patients between April 1, 2016, and July 12, 2019, with primary follow-up through 2020 and mean (SD) duration of 11.0 (3.0) months. Eligible patients were selected from 33 clinical research sites in the US. Patients had an index stroke attributed to large- or small-vessel disease and were 60 years or older or aged 50 to 59 years with at least 1 additional stroke risk factor. A total of 496 patients were enrolled, and 492 were randomly assigned to study groups (3 did not meet inclusion criteria, and 1 withdrew consent). Patients in the ICM group had the index stroke within 10 days before insertion. Data were analyzed from October 8, 2021, to January 28, 2022.InterventionsICM monitoring vs site-specific usual care (short-duration external cardiac monitoring).Main Outcomes and MeasuresThe ICM device automatically detects AF episodes 2 or more minutes in length; episodes were adjudicated by an expert committee. Cox regression multivariable modeling included all parameters identified in the univariate analysis having P values <.10. AF detection rates were calculated using Kaplan-Meier survival estimates.ResultsThe analysis included the 242 participants randomly assigned to the ICM group in the STROKE AF study. Among 242 patients monitored with ICM, 27 developed AF (mean [SD] age, 66.6 [9.3] years; 144 men [60.0%]; 96 [40.0%] women). Two patients had missing baseline data and exited the study early. Univariate predictors of AF detection included age (per 1-year increments: hazard ratio [HR], 1.05; 95% CI, 1.01-1.09; P = .02), CHA2DS2-VASc score (per point: HR, 1.54; 95% CI, 1.15-2.06; P = .004), chronic obstructive pulmonary disease (HR, 2.49; 95% CI, 0.86-7.20; P = .09), congestive heart failure (CHF; with preserved or reduced ejection fraction: HR, 6.64; 95% CI, 2.29-19.24; P < .001), left atrial enlargement (LAE; HR, 3.63; 95% CI, 1.55-8.47; P = .003), QRS duration (HR, 1.02; 95% CI, 1.00-1.04; P = .04), and kidney dysfunction (HR, 3.58; 95% CI, 1.35-9.46; P = .01). In multivariable modeling (n = 197), only CHF (HR, 5.06; 95% CI, 1.45-17.64; P = .05) and LAE (HR, 3.32; 1.34-8.19; P = .009) remained significant predictors of AF. At 12 months, patients with CHF and/or LAE (40 of 142 patients) had an AF detection rate of 23.4% vs 5.0% for patients with neither (HR, 5.1; 95% CI, 2.0-12.8; P < .001).Conclusions and RelevanceAmong patients with ischemic stroke attributed to large- or small-vessel disease, CHF and LAE were associated with a significantly increased risk of poststroke AF detection. These patients may benefit most from the use of ICMs as part of a secondary stroke prevention strategy. However, the study was not powered for clinical predictors of AF, and therefore, other clinical characteristics may not have reached statistical significance.Trial RegistrationClinicalTrials.gov Identifier: NCT02700945

Atrial Fibrillation In Patients With Stroke Attributed to Large- or Small-Vessel Disease

“…In contrast, the detection rate in patients undergoing standard monitoring remained low at 2.4% despite the performance of numerous intermittent recordings. Similar to the findings at 1 year, risk factors for ICM detection of AFDAS include heart failure and left atrial enlargement, with QRS duration and BMI achieving significance as additional risk factors . Most AF episodes in the ICM group were asymptomatic and most patients with AF had at least 1 episode greater than an hour.…”

“…Similar to the findings at 1 year, risk factors for ICM detection of AFDAS include heart failure and left atrial enlargement, with QRS duration and BMI achieving significance as additional risk factors. 7 Most AF episodes in the ICM group were asymptomatic and most patients with AF had at least 1 episode greater than an hour. AF burden increased over the course of monitoring in many patients with at least 6 minutes of AF detected.…”

“…It demonstrated that ICM was superior to usual care (12.5% vs 1.8% at 1 year) 4 and that patients with heart failure and/or left atrial enlargement were at significantly higher risk (23.4% vs 5.0% for patients with neither [hazard ratio [HR], 5.1; 95% CI, 2.0-12.8; P < .001]). 7 It remains unknown for how long after index stroke the detection of AFDAS continues to increase and whether the superiority of ICM over standard monitoring persists beyond 1 year in this patient population. Here, we present the results of the STROKE AF 3-year poststroke follow-up, rate of AFDAS, assessment of high-risk subgroups, AF burden, and clinical implications.…”

“…The Stroke of Known Cause and Underlying Atrial Fibrillation (STROKE AF) study measured the rate of AFDAS in patients with stroke attributed to LAD or SVD and multiple vascular risk factors. It demonstrated that ICM was superior to usual care (12.5% vs 1.8% at 1 year) and that patients with heart failure and/or left atrial enlargement were at significantly higher risk (23.4% vs 5.0% for patients with neither [hazard ratio [HR], 5.1; 95% CI, 2.0-12.8; P < .001]) . It remains unknown for how long after index stroke the detection of AFDAS continues to increase and whether the superiority of ICM over standard monitoring persists beyond 1 year in this patient population.…”