Division of Internal Medicine, University Hospital Basel, University of Basel, Basel, Switzerland. Department of Cardiology, Cardiovascular Research Institute Basel (CRIB), University Hospital Basel, University of Basel, Basel, Switzerland. Department of Nephrology, University Hospital Basel, University of Basel, Basel, Switzerland. Sphingotec GmbH, Hennigsdorf, Germany. Department of Nephrology, Kantonsspital Liestal, Liestal, Switzerland. Centro Cardiologico Monzino, Milan University, Milan, Italy.