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

Abstract

Background: The effect of withdrawal of digoxin on left ventricular function in patients with a history of idiopathic dilated cardiomyopathy (IDCM) following normalization of left ventricular ejection fraction (LVEF) with beta blockers remains unknown. Hypothesis: This study was undertaken to determine the effect of digoxin withdrawal on left ventricular function in patients with IDCM. Methods: In 8 consecutive patients with IDCM (5 men, 3 women) who had normalization of LVEF following beta-blocker treatment, digoxin was withdrawn as part of an office protocol, and LVEF was followed. Baseline EF prior to beta blocker initiation (carvedilol = 6, atenolol = 1, metoprolol = 1) was measured with isotope ventriculography (IVG), echocardiography, or left ventriculography. 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 was measured using IVG after digoxin withdrawal at a mean of 6.99 ± 4.34 months. 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 can result in a small but significant reduction in LVEF in patients with IDCM who had normalization of LVEF after treatment with beta blockers. Mean LVEF, however, remained within normal (> 50%) on beta-blocker therapy and without digitalis. Large, randomized controlled trials are needed to confirm these findings.