Background and objective: The cardiac safety of digoxin therapy for congestive heart failure (CHF) is a source of concern, especially among those with renal impairment.
Methods: Using a case-control design, we examined the risk of primary cardiac arrest (PCA) associated with digoxin therapy within three levels of renal function.
Results: After adjustment for other clinical characteristics, digoxin therapy for CHF was not associated with an increased risk of PCA [odds ratio (OR)=0.97, 95% confidence interval (CI) 0.59-1.62] among patients with normal renal function (serum creatinine </=1.1 mg/dL). In contrast, digoxin therapy was associated with a modest increase in risk (OR=1.58, CI 0.89-2.80) among patients with mild renal impairment (serum creatinine=1.2-1.4 mg/dL); and a twofold increase in risk (OR=2.39, CI 1.37-4.18) among patients with moderate renal impairment (serum creatinine=1.5-3.5 mg/dL).
Conclusions: These findings suggest that the risks of digoxin may offset the benefits among patients with moderately impaired renal function, but not among patients with normal renal function.