Probable benefit is defined as survival to six months on TAH-t System support with the same implanted TAH-t, without experiencing permanent disabling stroke-related deficits. This patient population, without treatment, has a poor prognosis of survival. Per M.L.A. Haeck, "Patients with drug refractory end-stage HF [heart failure] receiving support with inotropic drugs [have] a 3-, 6-, and 12-month survival of 51%, 26%, and 6%, respectively, with a mean survival of only 3.4 months."1