WARFARIN ANTICOAGULATION AND SURVIVAL - A COHORT ANALYSIS FROM THE STUDIES OF LEFT-VENTRICULAR DYSFUNCTION

Objectives. We sought to evaluate the relation between warfarin antico agulation and survival and morbidity from cardiac disease in patients with left ventricular (LV) dysfunction. Background. Warfarin anticoagu lation plays a major role in the management of patients who have had a large myocardial infarction and in those with atrial fibrillation. Ho wever, its use in patients with LV systolic dysfunction has been contr oversial. Methods. We reviewed data on warfarin use in 6,797 patients enrolled in the Studies of Left Ventricular Dysfunction (SOLVD) trial and analyzed the relation between warfarin use and all-cause mortality , as well as the combined end point of death or hospital admission for heart failure. We used Cox regression to adjust for differences in ba seline characteristics and to test for the interaction between warfari n use and selected patient variables in relation to outcome. Results. On multivariate analysis, use of warfarin was associated with a signif icant reduction in all-cause mortality (adjusted hazard ratio [HR] 0.7 6, 95% confidence interval [CI] 0.65 to 0.89, p = 0.0006) and in the r isk of death or hospital admission for heart failure (HR 0.82, 95% CI 0.72 to 0.93, p = 0.0002). Risk reduction was observed when each trial or randomization arm was analyzed separately, as well as in both gend ers. It was not significantly influenced by the presence of atrial fib rillation, age, ejection fraction, New York Heart Association function al class or etiology. Conclusions. In patients with LV systolic dysfun ction, warfarin use is associated with improved survival and reduced m orbidity. This association is primarily due to a reduction in cardiac events and does not appear to be limited to any particular subgroup. ( C) 1998 by the American College of Cardiology.