Systemic thromboembolism in chronic heart failure. A prospective study in 406 patients.

In patients with heart failure the risk of systemic thrombo-embolism and the benefit of anticoagulation are uncertain. To assess the incidence of systemic thromboembolism and the factors associated with an increased risk, 406 consecutive patients with chronic heart failure were prospectively investigated. Their left ventricular ejection fraction was 23 +/- 8%, pulmonary wedge pressure 19 +/- 10 mmHg and cardiac index 2.3 +/- 1.41. min-1.m-2 of body surface area. Two hundred patients were in NYHA functional class III-IV. Two hundred and thirty-two patients were receiving oral anticoagulants. Over a follow-up period of 16 +/- 11 months, thromboembolism occurred in 11 patients (2.7%), seven of whom were on anticoagulants. Among clinical, echocardiographic and haemodynamic variables, atrial fibrillation, more severe haemodynamic impairment and low exercise capacity were associated with increased thromboembolic risk. No echocardiographic findings, including the presence of intracavitary thrombi, either at baseline or during follow-up, were related to subsequent thromboembolic events. The rate of embolism did not differ in patients receiving anticoagulants (4%) compared with those who did not receive anticoagulants (1%). No major bleeding occurred during follow-up. Thus, in patients with chronic heart failure and sinus rhythm the incidence of systemic thromboembolism is low regardless of anticoagulant treatment. Atrial fibrillation, particularly when associated with low cardiac index, identifies a subgroup of patients at high risk of events. In this subgroup, a moderate-intensity anticoagulant regimen provides unsatisfactory protection against thromboembolism.