Association of Mortality Risk with High Serum Digoxin Concentrations

Abstract

Background

There are data suggesting a possible association of serum digoxin concentrations (SDC) and risk of mortality in patients treated with digoxin.

Objective

To determine whether SDCs in the therapeutic range of 1.2 to 2 ng/mL increase the risk of mortality when compared to a lower range of 0.5 to 1.1 ng/mL.

Methods

Retrospective cohort study to compare the risk of mortality in male patients with SDCs less than 1.2 ng/mL to patients with SDCs of 1.2 to 2 ng/mL.

Results

A total of 261 male patients were included, 191 (73%) had SDCs in the low range (0.5 to 1.1 ng/mL), and 70 (27%) had SDCs in the high range (at least 1.2 to 2 ng/mL). A high SDC showed a significant increase in risk for mortality with a hazard ratio (HR) of 1.656; 95 % HR confidence interval, 1.153 to 2.38; P = 0.0063.

Conclusion

Our results showed an increased risk of mortality in the high SDC group (1.2 to 2 ng/mL). This study's findings are consistent with the results of a post hoc evaluation of SDC in male patients in the DIG trial. ¹ A prospective trial is warranted to confirm our findings.