[Anticoagulation in primary prevention of thromboembolism in advanced left ventricular dysfunction]

Patients with heart failure have an increased risk for thromboembolic events. In clinical practice the physician is often confronted with the decision to establish a prophylactic anticoagulation.

The incidence for clinical embolization is 1.5 to 3.5% per year. It seems that patients with a lower peak oxygen uptake and with a lower ejection fraction are at higher risk for embolic events. There is no evidence for a correlation of such events with the clinical classification (NYHA) or with the genesis of heart failure. Concerning a prophylactic anticoagulation, the results of the published studies and meta-analyses are inhomogenous with a benefit in some, no difference in others and a significant disadvantage for the patients with anticoagulation in a part of them compared to a non-treated control group. None of these data is established by a prospective, randomized, controlled study with the primary endpoint thromboembolic event in patients with or without anticoagulation. The incidence for a hemorrhage under anticoagulation is 0.6-5.3% per year for life-threatening and 0.04-0.64% for fatal bleeding.

Because of similar incidences for thromboembolic events and for the bleeding complication of anticoagulation, there is no evidence for a general indication for anticoagulation of patients with heart failure, persistent sinus rhythm and lack of risk factors. In patients with high-grade heart failure (e.g. VO2max < 14 ml/min/kg body weight or left ventricular ejection fraction < 20-30%), who belong to a high-risk population, anticoagulation should be considered and may be acceptable in individual cases.