ANTICOGULATE OR NOT TO ANTICOGULATE PATIENTS WITH CARDIOMYOPATHY

Abstract

The current published literature does not indicate whether the long-term effect of anticoagulant or antiplatelet therapy contributes to mortality reduction in patients with LV dysfunction. Evaluating patients for personal risk for emboli or for ischemic coronary artery events may influence the choice of therapies. As more is learned about the mechanisms of drug effects in different populations, physicians may be better able to direct appropriate therapies. Until that time, one must weigh the risks and benefits of each drug alone and in combination. In NYHA class IV patients, the risk for thrombosis owing to spontaneous clotting increases as does the adverse potential of warfarin and the adverse effects of inhibiting prostaglandin mediated vasodilation by aspirin. In NYHA class I and II patients, the quality of life and convenience of multidrug therapy is weighed against the devastating effect of a major stroke. In less symptomatic patients, the long-term risk for acute coronary events may be higher than previously identified. This would suggest that all patients with depressed LV function should be on some type of antiplatelet or anticoagulant therapy. The current WATCH study will provide much needed information about the outcome differences between these agents. Conclusions based on available data include the following: Heart failure is increasing in incidence and prevalence. Atherosclerotic disease is an important causative factor for the development of heart failure or may be a comorbid condition in these patients. There is a measurable rate of stroke in patients with heart failure, although the cause of death in large studies is more often owing to sudden death or progressive heart failure. Sudden death may be from new ischemic events, asystole, or from ventricular tachyarrhythmias. In patients with heart failure, not all strokes are cardioembolic in origin. The benefits and risks of warfarin may be increased as the EF worsens or heart failure functional class declines. The interactions of aspirin and ACE inhibitors have been best evaluated for the hemodynamic effects. There may be additional factors hitherto not studied. The hemodynamic effect of ACE inhibitors may be more important in NYHA classes III and IV than in less symptomatic patients. Warfarin use has clear indications for patients in atrial fibrillation with mechanical prosthetic valves, in hypercoagulable states, and with a previous history of embolization. Aspirin is inexpensive and commonly available, but its use must be evaluated and articulated by the prescribing physician. The current multicenter prospective trials will provide much needed guidance on this subject. The ongoing trials do not have a placebo arm, however, indicating a consensus among clinicians that patients with cardiomyopathy should be on an antiplatelet or anticoagulant drug until further data emerge.