How safe and effective are new drugs for stroke prevention?

For decades, warfarin was the only oral blood thinner available to reduce the risk of stroke for patients with atrial fibrillation. Warfarin use is cumbersome, because it requires ongoing blood test to monitor the effect and has numerous drug and food interaction. Now a number of non-vitamin K antagonist oral anticoagulant (NOAC) drugs are available for patients with atrial fibrillation and claim to revolutionize the care for patients with atrial fibrillation.