the features of this patient (dilative cardiomyopathy, decreased FE, dilated hepatic artery) go for cardiac failure secondary to severe liver VMs, which is typically a dilative cardiomyopathy, initially at high output.
Some fundamental data are missing for understanding better the patient condition:
how’s the patient? (NYHA class?)
other cardiac performance data: CI, pulmonary pressures in particular? atrial fibrillation?
How large is hepatic artery?
CT data (VMs:where?) conflict with angiographic data, which however finds a dilated hepatic artery (typically associated to liver VMs); will you verify this discrepancy?
How about her LFTs? cholestasis?
If the high output cardiac failure secondary to severe liver VMs is confirmed, patient would require a more extensive assessment (including heart cath for pulmonary pressure assessment and search for other visceral VMs, lung and brain in particular); you should avoid cholecystectomy which could precipitate devastating ischemic cholecisto-cholangitis; start intensive cardiological treatment including appropriate anemia correction; start evaluation for OLT provided heart and pulmonary pressures are permissive (cardiac function improves markedly after OLT); bevacizumab 5 mg/kg every 21 days, 6 times for induction cycle is an option either as a bridge to OLT if there is a substantial hemodynamic response or as treatment (and in this case she will require maintenance therapy).
Hope these synthetic suggestions can be of some help; I also suggest you to read EASL guidelines re vascular disorders of liver just appeared on Journal of Hepatology, section Hereditary hemorrhagic telangiectasia.
HHT Center of reference, Crema, Italy