Usefulness of the MrWALLETS Scoring System to Predict First Diagnosed Atrial Fibrillation in Patients With Ischemic Stroke

Some cryptogenic strokes are caused by undetected paroxysmal atrial fibrillation (AF) and could benefit from oral anticoagulation. In this study, we searched for echocardiographic parameters associated with first diagnosed AF, to form a scoring system for the identification of patients with AF. We examined 571 patients with ischemic stroke (72.7 ± 13.5 years, 50.6% women), subdivided into 4 groups: documented cause without AF, first diagnosed AF, known paroxysmal AF, and permanent AF. All patients underwent transthoracic echocardiography, brain computed tomography scan, carotid/vertebral ultrasound, and continuous electrocardiographic monitoring. Eight factors independently characterized first diagnosed AF and formed the “MrWALLETS” score: mitral regurgitation, mild-to-moderate (+1), white matter lesions (−1), age ≥75 years (+1), left atrium ≥4 cm (+1), cerebral lesion diameter ≥4 cm (+1), left ventricular end-diastolic volume <65 ml (+1), tricuspid regurgitation ≥moderate (+1), carotid stenosis ≥50% (−1). In the patients with ≥3 points, positive predictive value was 80%, specificity 97.5%, and sensitivity 57.1%. In the patients with ≥2 points sensitivity rose to 85.7%, but positive predictive value was 47.1%. The area under the receiver-operating characteristic curve was 0.89 (95% CI 0.83 to 0.95). There were important differences among AF groups, which therefore could not be merged. In conclusion, 4 echocardiographic parameters, 3 additional instrumental parameters, and age allow the identification of stroke patients with first diagnosed AF with high positive predictive value.