ECONOMIC OUTCOMES OF WITHDRAWAL OF DIGOXIN THERAPY IN ADULT PATIENTS WITH STABLE CONGESTIVE-HEART-FAILURE

Objectives. This study sought to analyze the health and economic outcomes of withdrawal of digoxin therapy among U.S. adult patients with stable congestive heart failure. Background. New information regarding the outcomes of digoxin withdrawal has been provided by the Prospective Randomized Study of Ventricular Failure and Efficacy of Digoxin (PROVED) and Randomized Assessment of Digoxin and Inhibitors of Angiotensin-Converting Enzyme (RADIANCE) trials. We interpreted and extrapolated the results of these trials to describe implications on a national level. Methods. We used a decision-analytic model to estimate the outcomes of two alternative strategies to 1) continue and 2) withdraw digoxin in patients with congestive heart failure with normal sinus rhythm, New York Heart Association functional class II or III and left ventricular ejection fraction less than or equal to 35%. Epidemiologic assumptions were derived from published reports and expert opinion. Assumptions regarding the effectiveness of digoxin therapy were derived from the RADIANCE and PROVED digoxin withdrawal trials, Hospital and Medicare data were used for economic assumptions. Calculated outcomes included treatment failures, cases of digoxin toxicity and health care costs. Results. The continuation of digoxin therapy in these patients with congestive heart failure nationally would avoid an estimated 185,000 clinic visits, 27,000 emergency visits and 137,000 hospital admissions for congestive heart failure. After accounting for an estimated 12,500 cases of digoxin toxicity, the net annual savings would be $406 million, with a 90% range of uncertainty of $106 to $822 million. One-way sensitivity analysis indicated that digoxin therapy is cost-saving when the assumed annual incidence of digoxin toxicity is less than or equal to 33%. Conclusions. The continuation of digoxin therapy in patients with stable congestive heart failure should be strongly considered, because this strategy is likely to lead to both lower costs and greater health benefits on the basis of available information.