Digoxin withdrawal in patients with dilated cardiomyopathy following normalization of ejection fraction with beta blockers

Background: The effect of withdrawal of digoxin on left ventricular functio n inpatients with a history of idiopathic dilated cardiomyopathy (IDCNI) fo llowing normalization of left ventricular ejection fraction (LVEF) with bet a blockers remains unknown. Hypothesis: This study was undertaken to determine the effect of digoxin wi thdrawal on left ventricular function in patients with IDCM. Methods: In 8 consecutive patients with IDCM (5 men, 3 women) who had norma lization of LVEF following beta-blocker treatment, digoxin was withdrawn as part of an office protocol. and LVEF was followed. Baseline EF prior to be ta blocker initiation (carvedilol = 6, atenolol = 1, metoprolol = 1) was me asured with isotope ventriculography (IVG), echocardiography. or left ventr iculography. Post beta blocker ejection fraction (post BB EF) was measured in all patients with IVG at a mean of 17.25 +/- 5.38 months. Follow-up EF w as measured using IVG after digoxin withdrawal at a mean of 6.99 +/- 4.34 m onths. Results: An experienced blinded reader interpreted the IVG scans. Baseline EF was 28.5 +/- 8.26; post BB EF and follow-up EF were 56.1 +/- 4.65 and 51 .0 +/- 7.35, respectively (p = 0.05). Conclusion: These data provide potential evidence that digoxin withdrawal c an result in a small but significant reduction in LVEF in patients with IDC M who had normalization of LVEF after treatment with beta blockers. Mean LV EF, however. remained within normal (> 50%) on beta-blocker therapy and wit hout digitalis. Large, randomized controlled trials are needed to confirm t hese findings.