Dilated cardiomyopathy and role of antithrombotic therapy

There is no consensus as to whether anticoagulation has a favorable risk:benefit in reducing thromboembolic events in patients with heart failure (HF) secondary to dilated cardiomyopathy who do not suffer from atrial fibrillation or primary valvular disease.

The literature reviewed on this topic included most recent and ongoing studies that assessed the use of anticoagulation for this population. Several large retrospective studies showed an increased risk of thromboembolic events among patients with depressed left ventricular function. The relative risk of stroke in individuals with HF from all causes was found to be 4.1 for men and 2.8 for women, but confounding comorbidities (such as atrial fibrillation and coronary artery disease) were commonly present. Currently, there are no randomized prospective trials to guide the use of antithrombotics for these patients, and the risk of bleeding secondary to anticoagulation has limited the use of oral anticoagulants for prevention of thrombosis. Among patients with HF, increasing age directly correlates with both major bleeding and thromboembolic events, with a 46% relative risk of bleeding for each 10-year increase in age older than 40 years.

To date, there is no agreement on appropriate antithrombotic treatment (if any) for primary thromboembolism prophylaxis in patients with dilated cardiomyopathy with sinus rhythm. In recent years, several promising prospective trials were terminated prematurely due to inadequate enrollment. The Warfarin Aspirin-Reduced Cardiac Ejection Fraction trial may provide evidence regarding the use of anticoagulation for patients with decreased myocardial function.