Antithrombotic therapy for stroke prevention in patients with heart failure

Congestive heart failure (CHF) is associated with an increased risk of stroke mainly due stasis leading to increased risk of thrombus formation in the left ventricle and subsequent cerebral embolism. CHF patients are also at increased risk of atrial fibrillation (AF) that also leads to cerebral embolism. Aggressive medical management to prevent cardiac decompensation and maintain sinus rhythm is indicated in CHF patients. All patients with CHF and AF should be anticoagulated with warfarin or one of the newer oral anticoagulants. There is no clear indication for anticoagulation in CHF patients due to ischemic cardiomyopathy who are in sinus rhythm. Based on data from the WARCEF study (see below), those patients with CHF due to non-ischemic etiologies who are in sinus rhythm and have a left ventricular ejection fraction (LVEF) less than 30 % to 35 % may benefit from warfarin for the reduction of ischemic stroke risk, but warfarin does not increase survival. Whether warfarin is particularly beneficial for CHF patients who have a prior history of stroke or transient ischemic attack (TIA) is unknown. If, however, there is high enough suspicion that the stroke was of cardioembolic origin in patients with low LVEF, then anticoagulation would possibly be a reasonable option for prevention of recurrent stroke or TIA. Warfarin is indicated for stroke prophylaxis among those CHF patients who have an implanted mechanical device. The role of newer anticoagulants in patients with CHF who do not have AF is unknown at this time. Theoretically, there should be no reason against using these agents in place of warfarin in selected patients, particularly those with highly variable International Normalized Ratios (INR) in the context of warfarin therapy, but the newer anticoagulants have not yet been studied among CHF patients without concomitant AF.