Renal Function, Digoxin Therapy, and Heart Failure Outcomes

Abstract
Renal dysfunction is a common complication for patients with heart failure, but its association with clinical outcomes has not been fully characterized. We evaluated the association of glomerular filtration rate (GFR) with heart failure survival and the effect of digoxin on heart failure outcomes across GFR strata. A secondary analysis from the Digitalis Intervention Group trial was conducted of 6800 outpatients with systolic heart failure. Renal function was categorized as estimated GFR (expressed in ml/min per 1.73 m2). All-cause mortality (mean, 3 yr) was inversely proportional to GFR (GFR >60, 31% mortality; GFR 30 to 60, 46% mortality; GFR P < 0.001). Among patients with a GFR P < 0.0001). Digoxin efficacy did not differ by level of GFR (P = 0.19 for interaction). Renal dysfunction is strongly associated with mortality in stable outpatients with heart failure, notably in patients with estimated GFR 2. The effect of digoxin did not differ by level of renal function.