Management of heart failure. IV. Anticoagulation for patients with heart failure due to left ventricular systolic dysfunction.

OBJECTIVE: This article reviews the incidence of arterial thromboembolism in patients with heart failure who are not receiving anticoagulants. We also examine whether more severe ventricular dysfunction increases this incidence and the efficacy and risks of anticoagulation for patients in sinus rhythm.

DATA SOURCES: English-language studies referenced in MEDLINE or EMBASE (January 1966 to September 1993) were reviewed. We used the search terms heart failure, congestive; congestive heart failure; heart failure; cardiac failure; and dilated cardiomyopathy in conjunction with the terms anticoagulation, cerebrovascular disorders, stroke, and thromboembolism.

STUDY SELECTION: All studies with separate data for patients with chronic heart failure not receiving anticoagulants were included. Articles addressing valvular heart disease or heart failure secondary to acute myocardial infarction or Chagas' disease were excluded. Studies of the occurrence of left ventricular mural thrombi were also reviewed.

DATA EXTRACTION AND SYNTHESIS: Inclusion and exclusion criteria, prevalence of atrial fibrillation, mean follow-up, and the occurrence of arterial thromboembolic events were extracted. If the incidence was not given, this was estimated using the proportion of patients with events divided by the mean follow-up.

CONCLUSION: The incidence of arterial thromboembolism ranged from 0.9 to 5.5 events per 100 patient-years, with the largest studies reporting incidence of 2.0% and 2.4%. Findings regarding the relationship between ventricular function and thromboembolic events are contradictory. No controlled trial has assessed the efficacy or risks of anticoagulation for patients with heart failure and sinus rhythm, and reported efficacy in case series ranged from 0% to 100%. Until adequate studies are performed, anticoagulation should be discouraged for patients with heart failure who are in sinus rhythm.