More isn't always better, and that may be especially true when it comes to heart attack medications.

People with abnormal heart rhythms are at a higher risk of getting blood clots, which can cause a stroke. A blood-thinning medication may help. But some questions remain if these medications cause the bleeding.

Patients with atrial fibrillation, a common heart arrhythmia, have a higher risk of experiencing a stroke or blood clots. Warfarin (Coumadin) has long been the gold standard in treatment. That could be changing.

Heart failure patients often take medication to lower their risk of stroke, hemorrhage or dying. A common choice is warfarin (Coumadin), though a large clinical trial has found that cheaper over-the-counter aspirin may be just as effective.

Patients with certain types of atrial fibrillation, a common heart arrhythmia, are at a high risk of stroke and blood clots if they temporarily stop their blood thinning medication before surgery or permanently because of side effects.