1. From the Department of Cardiology (J.E.R.v.L., E.E.v.d.W.) and Department of Medical Statistics (A.H.Z.), Leiden University Medical Center, Leiden; Department of Internal Medicine (H.T.W., D.W.E.), University Medical Center Utrecht, Utrecht and Oosterschelde Hospital (H.W.O.R.v.L), Goes, the Netherlands. Correspondence to Ernst E. van der Wall, MD, Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, the Netherlands.