Brain natriuretic peptide and echocardiographic parameters as biomarkers for predicting new atrial fibrillation detection after acute ischemic stroke

Background: Detection of atrial fibrillation (AF) after ischemic stroke (IS) is crucial for starting anticoagulant therapy to prevent IS recurrence. Strategies to identify patients who might benefit the most from extended electrocardiography (ECG) monitoring would be highly desirable. Objectives: We aimed to investigate the role of brain natriuretic peptide (BNP) and echocardiographic parameters as biomarkers for predicting new AF detection in a large cohort of patients with acute IS. Design: We retrospectively analyzed data of 2411 consecutive patients admitted for IS to a single Stroke Center from January 1, 2018, to May 31, 2023. Methods: BNP levels were measured within 48 h of onset. Clinical and echocardiographic variables were evaluated. Single or multiple 12-lead ECG and continuous monitoring with external or implantable devices were used to detect new AF. The outcome measure was new AF detection at 3 months. Results: Of 2337 included patients, 1907 (81.6%) had not previously known AF, and new AF was detected in 422 (22%) patients. In the multivariate analysis, older age (odds ratio (OR) 1.03, 95% confidence interval (CI) 1.02–1.05, p < 0.001), higher National Institutes of Health Stroke Scale score (OR 1.05, 95% CI 1.03–1.07, p < 0.001), BNP ⩾150 pg/ml (OR 4.10, 95% CI 2.95–5.69, p < 0.001), and left atrium (LA) enlargement (OR 2.88, 95% CI 1.99–4.18, p < 0.001) were independently associated with new AF detection. The combination of both BNP ⩾150 pg/ml and LA enlargement showed a strong association (adjusted OR 4.74, 95% CI 3.47–6.48, p < 0.001) and a good discriminative performance for predicting new AF detection at 3 months (area under the receiver operating characteristic curve 0.74, 95% CI 0.71–0.77, sensitivity 0.70 (95% CI 0.65–0.74), specificity 0.78 (95% CI 0.76–0.80)). Conclusion: BNP ⩾150 pg/ml within 48 h of IS onset and LA enlargement, especially if combined, may be valuable biomarkers for predicting new AF detection and identifying patients who might benefit the most from extended ECG monitoring.