To my knowledge, there are no absolute medical contraindications for patients with hepatic hemangiomas and CoQ10. That said, I would discuss this with your father's personal physician first, as there may be other co-morbidities that may preclude use of CoQ10.
That said, there is no reliable evidence that CoQ10 consistently lowers blood pressure.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin Pho, M.D.
KevinMD.com
Twitter.com/kevinmd