Newly detected atrial fibrillation (NDAF) following an ischemic stroke (IS) or transient ischemic attack (TIA) is often paroxysmal in nature. While challenging to detect, extended ECG monitoring is often used to identify NDAF which has resource implications. Prognostic risk scores have been derived which may stratify the risk of NDAF and inform patient selection for ECG monitoring approaches after IS/TIA.
The overall aim was to identify risk scores that were derived and/or validated to predict NDAF after IS/TIA and evaluate their performance.
Summary of Review
A systematic literature review was undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, with application of the Quality Assessment of Diagnostic Accuracy (QUADAS)-2 tool. Published studies which derived and validated clinical risk scores in patients with IS/TIA, or externally validated an existing score to predict NDAF after IS/TIA were considered and independently screened by two reviewers. 21 studies involving 23 separate cohorts were analyzed from which 17 integer-based risk scores were identified. The overall frequency of NDAF was 9.7% (95% CI 8%-11.5%; I2=98%). The performance of the scores varied widely among derivation and validation cohorts (AUC 0.54-0.94); scores derived from stroke cohorts (12 scores) appeared to perform better (AUC 0.7-0.94) than those derived from non-stroke cohorts (5 scores; AUC 0.53-0.79). The scores also varied considerably in their complexity, ascertainment, component variables, participant characteristics, outcome definition and ease of application limiting their generalizability and utility.
Overall, the risk scores identified performed variably in their discriminative ability and the utility of these scores to predict NDAF in clinical practice remains uncertain. Further studies are required using larger prospective cohorts and randomized control trials to evaluate the usefulness of such scores for clinical decision making and preventative intervention.