A patient with new-onset atrial fibrillation and a CHA2DS2-VASc score of 4 without contraindications. What is the recommended stroke prophylaxis?

• A. Antiplatelet therapy alone
• B. Rate-control therapy only
• C. No therapy needed
• D. Initiate oral anticoagulation (prefer a DOAC if no contraindication)

Answer: (D)

The main point is that stroke risk in atrial fibrillation is best addressed with anticoagulation, and the level of risk guides therapy. A CHA2DS2-VASc score of 4 in new-onset AF places the patient in a high-risk category for ischemic stroke, so preventive anticoagulation is indicated. Antiplatelet therapy alone does not reduce stroke risk as effectively in AF, and rate-control therapy targets heart rate and symptoms rather than thromboembolism risk, so it doesn’t address the stroke danger. If there are no contraindications, starting oral anticoagulation is recommended. A direct oral anticoagulant is preferred when possible because it offers similar or superior protection against stroke, a lower risk of intracranial bleeding, and easier management (no routine INR monitoring) compared with warfarin, provided renal function and drug interactions are appropriate. No therapy would leave the patient at substantial stroke risk.