A 35-year-old patient in whom a Toyobo left ventricular assist device (LVAD) was implanted with descending aortic perfusion for the treatment of critical heart failure due to global myocardial infarction after repeat aortic root operations with a mechanical aortic valve developed complete thrombotic occlusion of the ascending aorta. This phenomenon was supposedly brought about by the patient's left ventricular contraction being too poor to open the mechanical aortic valve. The patient has, however, been doing well under LVAD support, with no thromboembolic events occurring for at least 2 years since the device was implanted.