The AS5F (age, stroke severity National Institutes of Health Stroke Scale [NIHSS] >5 to find atrial fibrillation) risk score was effective for identifying patients eligible for postischemic stroke prolonged electrocardiogram monitoring to detect paroxysmal atrial fibrillation (pAF), according to a study published in Neurology.
Data from a total of 3 prospective studies composed of 1556 patients with a transient ischemic attack (TIA) or stroke were pooled and analyzed. Studies performed prolonged Holter-electrocardiogram monitoring ≥72 hours in duration after TIA or stroke. One cohort was used to develop a clinical risk score based on the TRIPOD (transparent reporting of a multivariable prediction model for individual prognosis or diagnosis) guideline. This score was subsequently validated in 2 different studies.
Approximately 5% (n = 77) of patients had pAF detected during a 72-hour Holter monitoring. Variables predictive of pAF detection within 72 hours of Holter monitoring included age and stroke event, the latter of which was categorized by an NIHSS score of ≤5 (odds ratio 2.4 vs TIA; 95% CI, 0.8-6.9; P =.112) or stroke with an NIHSS score of >5 (odds ratio 7.2 vs TIA; 95% CI, 2.4-21.8; P <.001). These 2 variables were included in the final AS5F score (age, 0.76 points/year; stroke severity [NIHSS] ≤5, 9 points; NIHSS >5, 21 points). A predicted risk for detection of pAF between 5.2% and 40.8% was found to define a high-risk group, and a number needed to screen of 3 for the highest AS5F points.
A limitation of the proposed AS5F risk score includes its lack of validation in randomized controlled trials.
“In short, AS5F is a risk score based solely on clinical parameters that can easily be used by clinicians to select patients for prolonged Holter-ECG monitoring to increase the diagnostic yield of pAF after ischemic stroke or TIA and might improve the secondary preventive strategy in order to prevent recurrent ischemic strokes,” concluded the researchers.
Uphaus T, Weber-Krüger M, Grond M, et al. Development and validation of a score to detect paroxysmal atrial fibrillation after stroke. Neurology. 2019;92(2):e115-e124.