Letter by de Boer and van Veldhuisen Regarding Article, “Risk of Thromboembolism in Heart Failure: An Analysis from the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT)”
To the Editor:
We read with interest the recent article from Freudenberger et al.1 The major observation in this article is the incidence of thromboembolism in patients receiving contemporary heart failure management. The increased risk for thromboembolism in heart failure has been appreciated for quite some time, but whether preventive treatment with antiplatelet or anticoagulant agents is indicated in heart failure remains a controversial issue. Current American Heart Association/American College of Cardiology guidelines for the treatment of heart failure do not recommend standard treatment with antiplatelet or anticoagulant agents, except in patients with additional diseases such as coronary artery disease, atrial fibrillation, or ventricular thrombus, or with prosthetic valves.
Much to our surprise, treatment with anticoagulant agents (warfarin) was not associated with a lower rate of thromboembolic events in the analysis of Freudenberger et al.1 From the data presented, it remains somewhat unclear which patients are struck by thromboembolism, as the authors do not present data on what percentage of the patients using either antiplatelet or anticoagulant or no antithrombotic therapy developed a thromboembolic event. The authors speculate that the number of embolic events, mainly consisting of ischemic stroke, may have primarily been driven by hypertension and atherosclerosis rather than by cardiogenic embolism. Such a mechanism may have been predominant, because the current analysis excluded patients with prior atrial fibrillation or atrial flutter. Nevertheless, from a pathophysiological perspective, oral anticoagulants should theoretically reduce the occurrence of thromboembolism.
These data are important because they add to the currently scarce database on anticoagulant therapy in heart failure. Several (retrospective) analyses from heart failure cohorts2–4 have suggested that anticoagulant agents may reduce heart failure–associated mortality. Thus, next to amiodarone and an implantable cardioverter-defibrillator, available observational evidence suggests that treatment with anticoagulants may reduce morbidity and mortality in heart failure. A large prospective randomized trial testing the efficacy of antiplatelet and anticoagulant therapy in heart failure5 is eagerly awaited.