Plasma digoxin levels and ejection fraction in pediatric heart failure
Abstract: Digoxin has long been prescribed in children
with heart failure, but its efficacy has not been evaluated. A previous study
at the Department of Child Health, Dr. Cipto Mangunkusumo Hospital revealed
that plasma digoxin levels, following a maintenance dose of 15 μg/kg/d, were
sub-therapeutic. Regarding its narrow margin of safety, the trend is to use
digoxin in even lower dose. Thus, the drug’s impact on cardiac performance need
to be evaluated.
Objective To evaluate whether a lower maintenance dose of digoxin (10
μg/kg/d) is sufficient to achieve a therapeutic level and to assess for possible
correlations between plasma digoxin level and left ventricular ejection
fraction (LVEF) as well as fractional shortening (LVFS).
Methods A cross-sectional study was conducted on 20 pediatric heart
failure patients at the Department of Child Health, Dr. Cipto Mangunkusumo
Hospital, Jakarta, from January to May 2012. Plasma digoxin levels were
measured by ELISA method after one month or more of treatment; LVEF and LVFS
were measured by echocardiography. Correlations between plasma digoxin level
and LVEF or LVFS were analyzed by Spearman’s correlation test. The LVEF before
and after digoxin treatment were compared by paired T-test.
Results Thirteen out of 20 patients had plasma digoxin levels within
therapeutic range (0.5-1.5 ng/mL; 95%CI 0.599 to 0.898) and 7 had
sub-therapeutic levels (<0.5 ng/mL; 95%CI 0.252 to 0.417). No significant
correlations were observed between plasma digoxin level and LVEF (r=-0.085;
P=0.722) or LVFS (r=-0.105; P=0.659). There was a significant increase in LVEF
before [42.18 (SD 14.15)%] and after digoxin treatment [57.52 (SD 11.09)%], (P
< 0.0001).
Conclusion Most patients in this study have plasma digoxin levels within
therapeutic range. There are no significant correlations between plasma digoxin
level at the time point of measurement and LVEF or LVFS. However, an increase
of LVEF is observed in every individual patients following digoxin treatment.
Author: Nafrialdi, Sake Juli
Martina, Mulyadi M. Djer, Melva Louisa
Journal Code: jpkedokterangg150276
