What can realistically be achieved in most patients is a reduction in the burden of AF by prolonging the period to recurrence. Minimizing adverse effects is foremost. When therapy is commenced, normal electrolyte status is important and, with agents known to prolong the QT interval, the starting dose should be low and increased slowly. Patients should be well educated regarding potential drug interactions. Anticoagulation with warfarin reduces the risk substantially.
Efficacy varies with intensity of anticoagulation.
If the INR drops below 2, the risk of stroke increases. At an INR of 1.7, the risk is doubled. Above an INR of 4, the risk of intracerebral hemorrhage is increased. In some randomized studies of anticoagulation and lone AF, the event rates were not improved by warfarin therapy. Therefore, anticoagulation should be administered only to those who are most likely to benefit.