1. From the Scottish National Advanced Heart Failure Service, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (S.J.P., R.S.G., S.H.-Y., M.C.P.); Institute of Cardiovascular and Medical Sciences, BHF Glasgow Cardiovascular Research Center, University of Glasgow, Glasgow, United Kingdom (P.S.J., J.J.V.M.); Institute of Cardiovascular Medicine & Science, Liverpool Heart and Chest Hospital, Liverpool, United Kingdom (N.M.H.).