A 68-year-old male with a history of hypertension and type 2 diabetes presents to the clinic with complaints of intermittent palpitations, fatigue, and shortness of breath for the past week. He reports occasional episodes of dizziness but denies chest pain or syncope. The symptoms are more noticeable after mild exertion, such as climbing stairs. ECG Findings are significant for absence of P waves, irregular R-R intervals, and fibrillatory waves consistent with atrial fibrillation. You wanted to use CHA2DS2-VASc score as part of your management of this patient. What is the CHA2DS2-VASc score used to assess?